Ministry of Forests and Range Range Branch Biocontrol Development Group
BIOLOGICAL CONTROL AGENTS
BIOLOGICAL CONTROL AGENT: AGAPETA ZOEGANA L...... 4 Type of Agent: Root feeding moth ...... 4 Status: Secondary ...... 4 BIOLOGICAL CONTROL AGENT: APHTHONA CYPARISSIAE (KOCH) ...... 5 Type of agent: Root feeding flea beetle ...... 5 Status: Tertiary ...... 5 BIOLOGICAL CONTROL AGENT: BOTANOPHILA SENECIELLA (MEADE) ...... 7 Type of Agent: Seed feeding fly ...... 7 Status: Secondary ...... 7 BIOLOGICAL CONTROL AGENT: BRACHYPTEROLUS PULICARIUS L...... 8 Type of Agent: Seed feeding beetle ...... 8 Status: Tertiary ...... 8 BIOLOGICAL CONTROL AGENT: CHRYSOLINA HYPERICI (FORST.) ...... 9 Type of agent: Foliar feeding beetle ...... 9 Status: Tertiary ...... 9 BIOLOGICAL CONTROL AGENT: CHRYSOLINA QUADRIGEMINA (SUFFR.) ...... 10 Type of agent: Foliar feeding beetle ...... 10 Status: Tertiary ...... 10 BIOLOGICAL CONTROL AGENT: CHRYSOLINA VARIANS (SCHALLER) ...... 12 Type of agent: Foliar feeding beetle ...... 12 Status: Tertiary ...... 12 BIOLOGICAL CONTROL AGENT: CYPHOCLEONUS ACHATES (FAHR.) ...... 13 Type of agent: Root feeding beetle (weevil) ...... 13 Status: Secondary ...... 13 BIOLOGICAL CONTROL AGENT: GALERUCELLA CALMARIENSIS (L.) ...... 15 Type of agent: Foliar feeding beetle ...... 15 Status: Secondary ...... 15 BIOLOGICAL CONTROL AGENT: GALERUCELLA PUSILLA (DUFT.)...... 17 Type of agent: Foliar feeding beetle ...... 17 Status: Secondary ...... 17 BIOLOGICAL CONTROL AGENT: LARINUS MINUTUS GYLL...... 19 Type of Agent: Seed feeding beetle (weevil) ...... 19 Status: Secondary ...... 19 BIOLOGICAL CONTROL AGENT: LARINUS OBTUSUS GY ...... 21 Type of Agent: Seed feeding beetle (weevil) ...... 21 Status: Secondary ...... 21 BIOLOGICAL CONTROL AGENT: LARINUS PLANUS (F.) ...... 23 Type of agent: Seed feeding beetle (weevil) ...... 23 Status: Secondary ...... 23 BIOLOGICAL CONTROL AGENT: MECINUS JANTHINUS GERMAR...... 25 Type of agent: Stem mining beetle (weevil) ...... 25 Status: Secondary ...... 25 BIOLOGICAL CONTROL AGENT: METZNERIA PAUCIPUNCTELLA ZELL...... 27 Type of agent: Seed feeding moth ...... 27 Status: Secondary on Meadow knapweed ...... 27 Status: Tertiary on Spotted knapweed ...... 27 BIOLOGICAL CONTROL AGENT: MOGULONES CRUCIGER (HERBST) ...... 29 Type of agent: Root feeding beetle (weevil) ...... 29 Status: Secondary ...... 29 BIOLOGICAL CONTROL AGENT: PUCCINIA ACROPTILI SYD ...... 31 Type of agent: Leaf and stem rust (fungus) ...... 31 Status: Tertiary ...... 31 BIOLOGICAL CONTROL AGENT: PUCCINIA CHONDRILLINA BUBAK & SYD...... 32 Type of agent: Leaf and stem rust (fungus) ...... 32 Status: Tertiary ...... 32 BIOLOGICAL CONTROL AGENT: PUCCINIA JACEAE OTTH...... 34 Type of agent: Leaf and stem rust (fungus) ...... 34 Status: Tertiary ...... 34 BIOLOGICAL CONTROL AGENT: RHINOCYLLUS CONICUS FROEL ...... 35 Type of agent: Seed feeding beetle (weevil) ...... 35 Status: Primary on Marsh plume thistle ...... 35 Status: Secondary on Bull thistle, Canada thistle, Plumeless thistle and Scotch thistle ...... 35 Status: Tertiary on Nodding thistle ...... 35 BIOLOGICAL CONTROL AGENT: RHINUSA ANTIRRHINI (PAYKULL) ...... 37 Type of Agent: Seed head feeding beetle (weevil) ...... 37 Status: Secondary ...... 37 BIOLOGICAL CONTROL AGENT: RHINUSA NETA GERMAR ...... 39 Type of Agent: Seed head feeding beetle (weevil) ...... 39 Status: Tertiary ...... 39 BIOLOGICAL CONTROL AGENT: SCLEROTINIA SCLEROTIORUM (LIB.) ...... 40 Type of agent: Root, leaf and stem fungus ...... 40 Status: Tertiary ...... 40 BIOLOGICAL CONTROL AGENT: SPHENOPTERA JUGOSLAVICA OBENB...... 41 Type of agent: Root feeding beetle ...... 41 Status: Tertiary ...... 41 BIOLOGICAL CONTROL AGENT: TERELLIA RUFICAUDA (FAB.) ...... 43 Type of agent: Seed feeding fly ...... 43 Status: Secondary on Marsh plume thistle ...... 43 Status: Tertiary on Canada thistle ...... 43 BIOLOGICAL CONTROL AGENT: UROPHORA AFFINIS FRFLD...... 44 Type of Agent: Seed feeding fly ...... 44 Status: Tertiary ...... 44 BIOLOGICAL CONTROL AGENT: UROPHORA QUADRIFASCIATA (MEIG.) ...... 46 Type of Agent: Seed feeding fly ...... 46 Status: Secondary on Meadow knapweed ...... 46 Status: Tertiary on Diffuse and Spotted knapweeds ...... 46 BIOLOGICAL CONTROL AGENT: UROPHORA STYLATA F...... 48 Type of agent: Seedhead gall producing fly ...... 48 Status: Secondary ...... 48
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BIOLOGICAL CONTROL AGENT: AGAPETA ZOEGANA L. Its native distribution includes the former Yugoslavia, eastern Rumania, western Hungary and eastern Austria. Small populations Type of Agent: Root feeding moth occur in the Upper Rhine Valley, but it is absent in the Swiss Valais. Status: Secondary
BRITISH COLUMBIA EXPERIENCES Invasive Plant Species Attacked: Origin: Spotted knapweed. (Centaurea biebersteinii), The A. zoegana populations released in BC originate in Europe. Diffuse knapweed. (Centaurea diffusa)
History: Operational Field Guide: The first A. zoegana release was made in 1982. Since then, Agapeta zoegana - Operational Field thousands of adult moths have been collected and redistributed Guide, Ministry of Forests and throughout the province. In 1998 A.zoegana received secondary Range. status. Assisted redistribution is ongoing.
DESCRIPTION AND BIOLOGY Field results: Adult: A. zoegana is well dispersed in the southern interior and can be Adult moths are bright yellow and black. They are 1 - 2 cm long and seen frequently from mid June through mid August. Recent have a wingspan that measures 1.5 - 2.3 cm. Forewings are bright observations indicate, as A. zoegana disperses, its density declines. yellow with brown-black markings; hind-wings are dark grey. The Many larvae can be found on a single root, for example, 56 A females have a larger and more rounded abdomen than the males. zoegana larvae were found on a large root (over 20 cm long). The males have a pair of clasping pincers at the end of their Twenty-eight Cyphocleonus achates larvae were also present on this abdomen. Adults emerge from roots during mid June to mid August same root and begin to mate and lay eggs within 24 hours. Females oviposit 66 - 185 eggs individually or in groups of two or three onto leaves or Habitat: stems close to the crown, selecting plants with a root diameter of Releases have occurred in the Bunchgrass, 0 2.4 mm or larger. Temperatures between 18 - 30 C are best for Coastal Douglas-fir, Coastal western hemlock, mating. Cool, windy days will delay oviposition. Adults live 10 to 14 Interior cedar-hemlock, Interior Douglas-fir, days. Montane spruce, Ponderosa pine and Sub- boreal spruce biogeoclimatic zones. Egg: Establishment and dispersal has been found Eggs are initially white and turn yellow-red after four days. They are throughout each of these with the exception of flattened, oval shaped, measuring 0.75 mm x 0.45 mm. With the Montane spruce and Sub-boreal spruce magnification, a network of meshed lines can be observed on the zones. outer egg surface. Eggs hatch in seven to ten days. Collection for redistribution Larva and pupa: Using light suction, adults can be aspirated head first into prepared The larvae are segmented, with white bodies collection containers. Peak emergence periods are in early mornings and brown heads. Newly hatched larvae move or evenings. Adults rest low on the plants or on the soil surface to the root crown to begin feeding. The larvae during the day. Disturbing the plants will cause the adults to take develop through six instars. The first through short flights. fourth instars mine about 10 cm of the taproot over 40 - 45 days. As they mine the outer root NOTES layers, they produce a whitish web tunnel that A. zoegana can exist with other root feeding biocontrol agents, encloses around the larvae as they create a spiral trail downward including Sphenoptera jugoslavica and Cyphocleonus achates. before they return towards the top of the root. If they require
additional food, the larvae can move through the soil to adjacent roots within 10 cm. In 70 days the larvae will be mature in its sixth REFERENCES instar. Pupation takes about eight weeks which occurs the following Harris, P. 2007. Classical biological control of weeds established spring within the webbing. Multiple larvae can exist on a single root. biocontrol agent Agapeta zoegana (L.) Root-cortex feeder. Gov. of Can., Agriculture and Agri-Food Canada. January 15, 2007. Overwintering stage: It will overwinter in any larvae instar within the root. MFR STAFF OBSERVATIONS AND COMMENTS Muller, H., D. Schroeder and A. Gassmann. 1988. Investigations on LOCATION AND EFFECTIVENESS OF ATTACK Agapeta zoegana Haw. (Lep.: Cochylidae), a possible biocontrol Agapeta zoegana larvae feed on the outer layers of the root, agent of spotted knapweed Centaurea maculosa Lam. (Compositae) creating spiral tunnels which can kill small plants and prevent the in Canada. flowering of larger ones. When the larvae enter the root, they often Powell, G. W., A. Sturko, B. Wikeem and P. Harris. 1994. Field guide damage the vegetative stem bud, causing the plant to send up to the biological control of weeds in British Columbia. B.C. Min. For. multiple short stems instead of a single bolt. Plants may become Res. Prog. susceptible to secondary insect or pathogen attack. Rees, N. E., Quimbly, Jr., P. C., G. L. Piper, E. M. Coombs, C. E. Turner, N. R. Spencer, L. V. Knutson (editors). 1996. Biological PREDICTED AND NATIVE HABITAT control of weeds in the west. A. zoegana is common to the mesic, cooler areas where knapweed grows. Often it is associated with sites that have moderate humidity and temperatures within the Bunchgrass and Ponderosa pine biogeoclimatic zones. It can tolerate low winter temperatures, but it requires a long growing season. The literature states that sites over 1,000 m may not allow sufficient time for development. Suitable host plants have 2.4 mm diameter roots growing in undisturbed locations that are not mowed, grazed or cultivated.
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BIOLOGICAL CONTROL AGENT: APHTHONA CYPARISSIAE (KOCH) The larvae stage is the main factor of control as it feeds on the various roots, disabling the plants ability to absorb and store Type of agent: Root feeding flea beetle nutrients and moisture. The feeding will suppress the plants vigour Status: Tertiary and its reproductive ability, delay flowering, and weaken or kill plants. Invasive Plant Species Attacked: Leafy spurge Adult foliage feeding is quite impressive as they can completely (Euphorbia esula) consume small and young leaves, however the larvae contribute to the majority of the plant control. Each Aphthona species group Cypress spurge feeds in a specific manner; brown coloured flea-beetles, including A. (E. cyparissias) cyparissiae feed on the leaf margins. Adult feeding on leaf tissues and new shoots can impede photosynthesis, compounding nutrient DESCRIPTION AND BIOLOGY starvation. Adults usually remain close to the release showing Adult: immediate effects of attack, but tend to disperse after five years. Adults are light brown or coppery coloured, oval- Visual impacts seen at well established treatment sites: shaped and measure 3 - 4 Reduced number of flowering stems; mm long. Their unique A temporary increase of short, non-flowing stems is common, feature, a dark brown gap at and will disappear after about four years; and the top of the wing-covers Native grasses replace the voids left from dead spurge. distinguishes them from other Aphthona species. PREDICTED AND NATIVE HABITAT Adults begin to emerge in late June and continue through to August, A. cyparissiae prefers habitats similar to that of A.nigriscutis, but in often persisting later in lower numbers. As with all Aphthona slightly moister areas often located in the bottom third of valley species, adults congregate for feeding, mating and egg-laying. Adults slopes and in depressions. They prefer spurge sites within a will breed almost immediately and begin to lay eggs within one bunchgrass plant community where soils have a sand content week. Intensive egg-laying lasts for two months before it slows for between 40 and 60%. A. cyparissiae will do well in areas where A. another two months. Eggs are deposited slightly underground near nigriscutis populations have decreased from the result of increased spurge roots in clusters of 20 or 30 every 3 - 5 days. Each female will moisture. Of all the Aphthona species in BC, this species is most lay up to 285 eggs during this period. Aphthona cyparissiae has a tolerant of spurge at low density rates of 50 - 125 stems/m2and longer oviposition period than A. nigriscutis. This species remains when mature plants reach at least 51 cm tall. It will not compete high on plants during warm summer days, often taking short flights. well at locations where there are high ant populations. A climate On warm days it avoids predation by jumping readily, but as 0 0 with a 4-month period of temperatures of 10 or less is required for temperatures drop to 10 C or less, they move less and are complete development. A. cyparissiae shows a strong preference for susceptible to animal grazing. cypress spurge over leafy spurge.
Egg: RITISH OLUMBIA XPERIENCES Eggs measure 0.7 x 0.4 mm. During the three week incubation B C E period, the pale coloured eggs darken to brown-yellow. Origin: The A. cyparissiae populations released in BC originated from Larva and pupa: Eurasian stock reared in Alberta and Saskatchewan. Elongated, slender, white larvae with brown heads often maintain a slight 'comma' shape History: through the three instars. Upon emergence, The first A. Cyparissiae BC release in BC occurred in 1989 in the east the larvae often feed together in small groups Kootenays. In 1994, a population mixed with A. nigriscutis was in a parallel formation on the youngest roots, released near Kamloops, and flourished within three years. Several avoiding the latex producing layers. The first thousands of adults have been collected from this location for instar completes in eight days. The second redistribution and today the site has significantly less spurge. Since instar lasts 25 to 30 days and it no longer 1989 almost 100 A. cyparissiae releases have been made in BC. A. avoids the latex as it feeds on the outer tissue of older roots and cyparissiae and A.nigriscutis occur in mixed populations, dispersing freely moves between them. This feeding pattern continues for 45 freely in BC. days through the third instar. The damage the larvae create initiates new growth the next year, causing the plant to send out new shoots Field results: from the attacked locations. This is essential for the insect's survival. Past monitoring results found mixed A. cyparissiae/A. nigriscutis These new shoots provide an abundance of young roots for larvae populations established and well dispersed at most the release sites. feeding the next year and may subsequently increase the adult It is difficult to separate these two species and, therefore, it is population. At optimal temperatures, the larvae feeding stage will acceptable to consider them as mixed populations in field results. last 75 to 80 days. When lower temperatures arrive, the larvae Adult populations drop significantly when the plants become dried prepare for further development by returning to the soil. Complete in August. When temperatures rise rapidly over a short period, development requires a 4-month period with temperatures at 100C adults become harder to locate (adults found abundantly in 1998 or less, (surviving to -130C). Larvae which fail to complete the disappeared quickly after several consecutive, intensely hot days). required feeding before the onset of winter will not finish development. Pupation takes 28 to 57 days, occurring the following Habitat: year during late spring or early summer. A. cyparissiae has been released and found established in the Bunchgrass and Interior Douglas-fir biogeoclimatic zones. It has also Overwintering stage: been released into the Sub-boreal spruce zone, but there is no Mature larvae overwinter in a prepared pupal chamber within the record of it becoming established before a high risk invasive plant soil. established on the site and required immediate herbicide treatment.
LOCATION AND EFFECTIVENESS OF ATTACK Collection for redistribution
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Sweep for adults through early summer on warm and hot days and aspirate to clean the collection. During bright, hot days, adults rapidly rise on plants, allowing for repeat sweeping. Sites are usually harvestable by three years following treatment.
Literature sources indicate new treatments provide earlier results when large numbers are released. When treatments are made with small numbers, the resulting populations tend to persist with small numbers, never showing a significant upward surge in population.
NOTES A. cyparissiae and A. nigriscutis habitats overlap and are visually similar, making identification between the two difficult.
REFERENCES Harris, P. 1994. Biological control of leafy spurge on the prairies. Leafy Spurge News. Vol. XVI, Issue 3: 2.
Harris, P. 2006. Classical biological control of weeds. Established biological control agent Aphthona cyparrisiae (Koch). Root beetle. Agriculture and Agri-Food Canada. December 8, 2006.
Mason, P. G. and J. T. Huber. Biological control programmes in Canada, 1981-2000.
MFR STAFF OBSERVATIONS AND COMMENTS Powell, G. W., A. Sturko, B. Wikeem and P. Harris. 1994. Field guide to the biological control of weeds in British Columbia. B.C. Min. For. Res. Prog.
Rees, N. E., Quimbly, Jr., P. C., G. L. Piper, E. M. Coombs, C. E. Turner, N. R. Spencer, L. V. Knutson (editors). 1996. Biological control of weeds in the west.
Saskatchewan Agriculture and Food and Saskatchewan Rural Development. No date. Biological control of leafy spurge. Farm Facts. Gov. of Can. 3 p.
Spencer, N. R. 1997. Niche specificity of insects introduced for leafy spurge control. Leafy Spurge News. Vol. XIX, Issue 1: 8.
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BIOLOGICAL CONTROL AGENT: BOTANOPHILA SENECIELLA Initially B. seneciella was introduced to BC into 1968. The lack of establishment was blamed on poor synchronization of plant and (MEADE) agent. Releases were made again in 1970 in the Fraser Valley and Type of Agent: Seed feeding fly today it is broadly dispersed in the Fraser Valley, on Vancouver Status: Secondary Island and also in the Okanagan. It is the only tansy ragwort agent established beyond the lower mainland at this time. Invasive Plant Species Attacked: Tansy ragwort (Senecio jacobaeae) Field results: B. senenciella is the only tansy ragwort biocontrol agent to establish DESCRIPTION AND BIOLOGY in the Okanagan. It was not intentionally released here and how or Adult: when it arrived is not known. By mid to late September, some larvae The dull grey adults are similar to were still present in seedheads. houseflies. They have slightly clouded, clear wings that extend Habitat: beyond their body, ranging from 4 - 6 mm long. The female's B. seneciella was originally released into the Coastal western abdomen is conical, while the male's is narrow and both are covered hemlock biogeoclimatic zone. It has since freely dispersed itself with short hairs. Adults emerge to coincide with floral bud within the Coastal Douglas-fir, Coastal western hemlock, and formation of tansy ragwort. Females can be observed walking over Interior Douglas-fir zones. bolting plants investigating floral bud suitability. Appropriate buds used for oviposition will be 3 - 4 mm in diameter. Egg-laying Collection for redistribution coincides with floral development, usually about one week after B. seneciella has dispersed itself freely enough to no longer warrant they emerge. Females deposit eggs individually near the top of collections for new releases in most situations. If releases are developing seeds between floral bracts. Adult life span is about 44 required, larvae transfers are best suited for this agent by days. transplanting infested plants to new locations. Larvae can be transferred in a variety of methods: Egg: Releasing 1,000 to 1,500 seedheads average 10 to 15 % attack Eggs incubate for 3 - 4 days. and is sufficient to create a new colony; Plants can be transplanted to new sites by moving infested Larva and pupa: plants just before peak bud formation to ensure seed heads Creamy white larvae emerge during June, July and early August. At are infected. Transfers made too early or too late can result in high elevations, emergence may be delayed until July. Three larvae non-viable treatments; instars feed for 26 - 29 days, developing to 4 - 6 mm long while Infested plants can also be harvested in late summer and by consuming part or all of the seeds. Early stages of seedhead attack keeping plant roots adequately moist and their stems placed can be identified by observing a frothy secretion appearing from a on sand allows the larvae to leave the heads and pupate in the small brown puncture dot. Late stages are recognized by tufts of sand. The sand is then stored in a cool location and placed at sticky brown florets or white pappus appearing from between the release point the following spring; and bracts. Infected seedheads, when opened, will expose the larvae or Adults can also be swept as an alternative to larvae/pupae feeding evidence - a hollow black cavity. Larvae mature in late transfers. Adult collections can occur in the early mornings summer, exit the seedheads and move to the soil to pupate. A dark when the temperatures are still cold. By keeping the adult flies brown puparium is developed five days after the larvae enters the cool and dry they can survive up to one week before they must soil and remains there until the following spring. be released.
Overwintering stage: NOTES Pupae overwinter within the soil. B. seneciella is also known as Hylemya seneciella Meade and Pegohylemyia seneciella. LOCATION AND EFFECTIVENESS OF ATTACK It can co-exist with Longitarsus spp. and Cochylis atricapitana, Larvae feed in developing seedheads, often consuming all seeds and but is a poor competitor against T. jacobaeae. Isolated small reproductive floral parts. The best control has been on small sites or widely spaced individual plants are undesirable for T. isolated tansy ragwort patches where 30% of flower heads are jacobeae. B. seneciella will establish in these types of attacked. On large sites, the rate of attack plummets to 2%. infestations, subsequently avoiding competition and filling a Botanophila seneciella , on its own, is unable to provide adequate specific niche. control, but contributes to the overall desired affect when released It is not a strong invasive plant control agent but is the only onto sites with Longitarsus spp. or Cochylis atricapitana. one to establish east of the Cascade Mountains.
PREDICTED AND NATIVE HABITAT REFERENCES B. seneciella appears to have few site restrictions, establishing easily Harris, P. 2003. Classical biological control of weeds established on tansy ragwort growing in variable habitats. It has shown a biocontrol agent Botanophila seneciella a (Meade). Seed-head fly. preference for the open habitat of meadows, forest openings and Agriculture and Agri-Food Canada. May 20, 2003. right-of-ways. Commonly it attacks plants in semi-shaded areas with light canopy but avoids heavy shade. It fills a niche for areas less MFR STAFF OBSERVATIONS AND COMMENTS desired by other agents, specifically Tyria jacobaeae. It has superior Powell, G. W., A. Sturko, B. Wikeem and P. Harris. 1994. Field guide host seeking capabilities and can easily locate isolated patches of to the biological control of weeds in British Columbia. B.C. Min. For. tansy ragwort. Res. Prog.
BRITISH COLUMBIA EXPERIENCES Rees, N. E., Quimbly, Jr., P. C., G. L. Piper, E. M. Coombs, C. E. Origin: Turner, N. R. Spencer, L. V. Knutson (editors). 1996. Biological The Canadian B. seneciella populations came from French stock control of weeds in the west. reared in California. History:
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BIOLOGICAL CONTROL AGENT: BRACHYPTEROLUS PULICARIUS L. It is unknown where the source of the B. Pulicarius populations, found in BC, originated. Type of Agent: Seed feeding beetle Status: Tertiary History: B. pulicarius was found in Saskatchewan by 1950. It is believed to Invasive Plant Species Attacked: have entered into Canada via the accidental introduction from New Dalmatian toadflax York, where it was first noticed in 1919. The first B. pulicarius (Linaria dalmatica), release in BC was made near Grand Forks in 1989. No further Yellow toadflax assisted redistribution efforts continued because it was found to (L. vulgaris), already be well established in BC. Narrow-leaved Dalmatian toadflax Habitat: (L. genistifolia spp. B. pulicarius is found in the Bunchgrass, Coastal western hemlock, dalmatica) Interior cedar hemlock, Interior Douglas-fir, Ponderosa pine and Sub-boreal spruce biogeoclimatic zones. DESCRIPTION AND BIOLOGY Adult: Field results: The beetles are shiny black, elongate to oval, 2.4 x 1.0 mm, and B. pulicarius has self dispersed and is commonly found throughout sparsely covered with hairs. Short wing covers expose the last the toadflax infestations and appears to have no preference for one abdominal segments of their bodies. Females have slightly longer variety over the other. Early reports show that toadflax inventory covers than the males. Rear legs are darker than the other legs. and B. pulicarius dispersal occurred in many areas of BC. Although it Near equal male/female ratio adults begin to appear in early May, may not be present in its adult form at the same time as other usually when the plants are 15 - 20 cm tall. Adults congregate and biocontrol agents, it is often found sharing sites with Rhinusa spp., feed on pollen, flowers and on young foliage, sometimes completely Calophasia lunula, and Mecinus janthinus. consuming terminals. Mating occurs in June when the plants begin to bud. Heavy feeding can cause significant flower loss, which may Collection for redistribution delay oviposition until the second flowering cycle in July. Eggs are Wide dispersal of this agent eliminates the need to collect and laid individually or in small clusters of up to three into unopened release B. pulicarius in most circumstances. Adults can be swept floral buds. Adults live one to three months and populations begin from plants in early summer. Aspirating adults is efficient and less to subside by August. destructive to plants.
Egg: NOTES The eggs are white and measure 0.6 mm long. Just prior to hatching, B. pulicarius directly competes with Rhinusa antirrhini and R. the eggs turn yellow. neta.
Larva and pupa: REFERENCES Pale yellow larvae with brown heads emerge and begin feeding on Harris, P. 1961. Control of toadflax by Brachypterolus pulicarius (L.) the reproductive parts of the flowers and move between flowers (Coleoptera: Nitidulidae) and Gymnaetron antirrhini (Payyk.) and developing buds. Smaller flowers are less nutritious than larger (Coleoptera: Curculionidae) in Canada. ones and, therefore, the quantity of floral damage each larva
destroys relates to bloom size. Older larvae will feed on seeds. Harris, P. 2005. Classical biological control of weeds established Mature larvae move into the soil to pupate. Yellow pupae measure biocontrol agent Brachypterolus pulicarius L flower-feeding beetle. 2. 8 x 2. 0 mm and develop for three weeks. Gov. of Can., Agriculture and Agri-Food Canada. February 1, 2007.
Overwintering stage: Hervey, G. E. R. No date. A European Nitidulid, Brachypterolus Most overwinter as pupae, however adults can overwinter in pulicarius L. (Coleoptera, Family, Nitidulidae). Journal of Economic climates with long growing seasons. Entomol., Vol. 20: 809-814.
Location and effectiveness of attack Adults feed first on early succulent terminal growth, causing MFR STAFF COMMENTS AND OBSERVATIONS extensive damage and later move onto flowers and floral buds as Powell, G. W., A. Sturko, B. Wikeem and P. Harris. 1994. Field guide they become available. Stem and terminal damage initiates to the biological control of weeds in British Columbia. B.C. Min. For. branching. Heavy attack causes delayed bloom until July or August. Res. Prog. Larvae feed on the reproductive parts of the plants and developing seeds. Brachypterolus pulicarius feeding reduces the first bloom by Rees, N. E., Quimbly, Jr., P. C., G. L. Piper, E. M. Coombs, C. E. 95%; the second by 82%; and, the third by 52%. Overall seed Turner, N. R. Spencer, L. V. Knutson (editors). 1996. Biological production is reduced by 74% and each beetle is responsible for control of weeds in the west. destroying 76.5 seeds. Heavy foliar feeding can help reduce plant vigour. Smith, J. M. 1959. Notes on insects, especially Gymnaetron spp. (Coleoptera: Curculionidae), associated with toadflax, Linaria Predicted and native habitat vulgaris Mill. (Scrophulariaceae), in North America. The Can. The adventive biocontrol agent, B. pulicarius is abundant and Entomol., Vol. XCI, No. 2. Pp. 118-119. common in all Canadian provinces that support yellow and Dalmatian toadflax varieties. It shows a preference for yellow toadflax but is commonly found on both. It has a broad range of climatic and habitat preferences, from warm to hot open sites, to warm, slightly moist semi-shaded locations. Sites with coarse sandy and poor soils are common with the plant and B. pulicarius. In Europe B. pulicarius is wide spread. BRITISH COLUMBIA EXPERIENCES Origin: 8 | P a g e
BIOLOGICAL CONTROL AGENT: CHRYSOLINA HYPERICI (FORST.) C. hyperici released in BC came from reared populations from Loftus, California. The California stock arrived from Australia that Type of agent: Foliar feeding beetle originated from populations from Great Britain. Status: Tertiary History: Invasive Plant Species Attacked: C. hyperici was one of the two species introduced to BC near St. John's wort (Hypericum perforatum Fruitvale in 1951. Imported populations for field release continued for several years. These early established releases provided DESCRIPTION AND BIOLOGY collection sources for future BC populations and the first field Adult: collection occurred in 1981. Over the next few years Chrysolina The beetles are metallic bronze-green coloured and measure 5.3 - species were released in several locations in the southern interior. 6.1 mm long. The adults emerge in early June and begin feeding in Subsequent releases have established and the beetles have clusters on young terminal leaves, flower buds or the underside of dispersed freely with limited assistance. leaves. They continue to feed until leaf drop in July and early August. Reproduction is related to day length, with longer daylight, Field results: less feeding and reproduction occurs. This changes when day length In recent years St. John's wort has been re-establishing and, is reduced. At this time they move into plant litter and await the fall therefore, renewed efforts have been underway to assist with rains. A significant amount of moisture is needed to break redistributing the beetles in mixed populations. In the southern dormancy. If dormancy is not broken, mating and egg-laying is interior, larvae are readily seen in May and adults are abundant in delayed until the following spring, which is often the case in June. Canadian habitat. Adults that do reappear in the autumn will mate. Females oviposit up to 2000 eggs individually or in small clusters Habitat: onto basal winter foliage. Chyrsolina hyperici adults are hardier, Releases have been made into the Coastal western hemlock, Interior smaller, and appear later in the spring than C. quadrigemina. Douglas-fir and Ponderosa pine biogeoclimatic zones. Establishment Colouring can vary between sites, more bronze coloured adults are was found at the Interior Douglas-fir zone site and is suspected to found in mild climates. be established in the other zones in a mixed population. Dispersal of Chrysolina species is found in Coastal Douglas-fir, Coastal western Egg: hemlock, Engelmann spruce-subalpine fir, Interior Douglas-fir, The elongated 1.2 mm x 0.5 mm orange eggs overwinter and hatch Montane spruce and Ponderosa pine zones. Some southern interior the following spring. The eggs are susceptible to desiccation. habitats include elevations to 1100 m. On dry Ponderosa pine sites, C. hyperici replaces C. quadrigemina. Larva and pupa: The plump, humped-back larvae, initially orange coloured, change Collection for redistribution to dirty pink-grey as they mature. Newly hatched larvae usually By early June, adults can be swept when they cluster on the plants. appear in the spring, although some will hatch in the fall. They feed on leaf buds and immature leaves causing complete defoliation NOTES before moving on to adjacent plants. Feeding on St. John's wort C. hyperici are similar to other Chrysolina species released in causes the larvae to become light sensitive. Photosensitivity BC making identification difficult in the absence of the other prevents them from feeding during the day, therefore they must species for comparison. C. hyperici adults are smaller than C. feed during low light periods, and do so before sunrise. After the quadrigemina and emerges later in the fall. They also more morning feed they seek shade and protection, the smallest hide in frequently delay oviposition until spring, therefore, laying leaf buds while the larger ones move under the plants or into the fewer eggs in the fall. Of the two, C. hyperici is hardier. soil. They resume feeding at sunset. Mature larvae burrow into the Summer rains do not affect its dormancy. soil during late spring and early summer and create a pupal cell.
REFERENCES Overwintering stage: Harris, P. 2003. Classical biological control of weeds established In most cases it overwinters as an egg. However adults and larvae biocontrol agent Chrysolina hyperici (Forst.). Defoliating beetle. Gov. can also overwinter; both have good winter survival in mild climates of Can., Agriculture and Agri-Food Canada. May 20, 2003. or under snow cover.
Harris, P. and D. P. Peschken. 1971. 32. Hypericum perforatum L., St. LOCATION AND EFFECTIVENESS OF ATTACK John's wort (Hypericaceae). Biological Control Programmes Against Early spring larvae feedings on fleshy new growth cause the most Insects and Weeds in Canada 1959-1968. Commonwealth damage. This timing is the controlling key. Although adult feeding Agricultural Bureaux. Pp. 90. can be impressive, it has less impact than larvae feeding. Heavy fall feeding may cause some impact on the plants ability to overwinter. Manitoba Agriculture. No date. St. John's wort (Hypericum perforatum L.). Brochure. Gov. of Man. PREDICTED AND NATIVE HABITAT C. hyperici adapts well to ocean or maritime climates, accepting MFR FIELD OBSERVATIONS AND COMMENTS moister sites than C. quadrigemina and tolerates higher summer Powell, G. W., A. Sturko, B. Wikeem and P. Harris. 1994. Field guide precipitation than other species. It can withstand cold climates with to the biological control of weeds in British Columbia. B.C. Min. For. little or no snow cover. It requires soft soils, sites which are rocky or Res. Prog. barren are undesirable. It needs open sunny locations; avoiding shaded and forested areas. It is adaptable to environmental Rees, N. E., Quimbly, Jr., P. C., G. L. Piper, E. M. Coombs, C. E. conditions, enabling it to persist when other species fail. Turner, N. R. Spencer, L. V. Knutson (editors). 1996. Biological C. hyperici is native in the Atlantic regions of Europe. In Scandinavia control of weeds in the west. it is restricted to the coastal areas. In Rumania it has shown a higher tolerance for dry conditions than C. varians.
BRITISH COLUMBIA EXPERIENCES Origin:
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BIOLOGICAL CONTROL AGENT: CHRYSOLINA QUADRIGEMINA It tolerates dryer climates than C. hyperici. It requires snow cover or plant litter in areas that experience severe frost. (SUFFR.) Type of agent: Foliar feeding beetle BRITISH COLUMBIA EXPERIENCES Status: Tertiary Origin: C. quadrigemina released in BC came from reared populations in Invasive Plant Species Attacked: Loftus, California. California sources came from Australia originating St. John's wort from Mediterranean France stock. (Hypericum perforatum) History: DESCRIPTION AND BIOLOGY C. quadrigemina was one of two Chrysolina species introduced to BC Adult: near Christina Lake in 1952. Imported populations for field release The beetles are metallic continued for several years. Over the next few years Chrysolina bronze, green, blue, species were released in several locations in the southern interior. purple or black coloured These early established releases provided collection sources for and measure 6.1 - 7 mm long. The adults emerge in early June and future BC populations and the first field collection occurred in 1981. begin feeding in clusters on young terminal leaves, flower buds or Subsequent releases have established and the beetles have the underside of leaves. They continue to feed until leaf drop in July dispersed freely with limited assistance. and early August. Reproduction is related to day length, the longer daylight, less feeding and reproduction occurs. This changes when Field results: day length is reduced. At this time they move into plant litter and In recent years St. John's wort await the fall rains which break their dormancy and encourage them has been re-establishing and, to return to the upper plant portions to mate. Females oviposit up therefore, renewed efforts to 1,500 eggs individually or in small clusters onto winter basal have been underway to assist foliage. with redistributing the beetles in mixed populations. In the Egg: southern interior, larvae are The eggs are reddish coloured and measure 1.2 mm x 0.5 mm. They readily seen in May and adults overwinter and hatch the following spring. Chrysolina quadrigemina are abundant in June. eggs are more resistant to desiccation than those of C. hyperici and C. varians. Habitat: Pure C. quadrigemina and mixed populations have been released Larva and pupa: into the Coastal western hemlock and Interior Douglas-fir The plump, hump-backed larvae, initially orange coloured, change biogeoclimatic zones. Establishment and dispersal of Chrysolina to dirty pink-grey as they mature. Newly hatched larvae usually species have been found in Coastal Douglas-fir, Coastal western appear in the spring, although some will hatch in the fall. They feed hemlock, Engelmann spruce subalpine-fir, Interior cedar hemlock, on leaf buds and immature leaves causing complete defoliation Interior Douglas-fir, Montane spruce and Ponderosa pine zones. It before moving onto adjacent plants. Feeding on St. John's wort has spread through the Fraser Valley and lower mainland, adapting causes the larvae to become light sensitive. Photosensitivity to the higher precipitation levels. Larvae are readily seen in May prevents them from feeding during the day, therefore they must with adults abundant in June. feed during low light periods, and do so before sunrise. After the morning feed they seek shade and protection, the smallest hide in Collection for redistribution leaf buds while the larger ones move under the plants or into the By early June, adults can be collected by sweeping as they cluster on soil. They resume feeding at sunset. In mid May the larvae are the plants. mature and burrow into the soil and create a pupal cell. NOTES Overwintering stage: C. quadrigemina are very similar to other Chrysolina species Usually they overwinter as eggs on basal leaves. In mild climates the making identification difficult in the absence of the other larvae and adults will survive the winter if temperatures remain species for comparison. C. quadrigemina adults are larger and 0 above -8 C. often lay more eggs in the fall than in the spring than C. hyperici. LOCATION AND EFFECTIVENESS OF ATTACK C. quadrigemina larvae emerge slightly earlier in the spring Early spring larval feedings on fleshy new growth cause the most than C hyperici. damage; this timing is the controlling key. Although adult feeding can be impressive, it has less impact than larvae feeding. Heavy fall REFERENCES feeding may cause some impact on the plants ability to overwinter. Harris, P. 2003. Classical biological control of weeds established biocontrol agent Chrysolina quadrigemina (Suffr.). Defoliating PREDICTED AND NATIVE HABITAT beetle. Gov. of Can., Agriculture and Agri-Food Canada. May 20, C. quadrigemina prefer elevations below 1000 m and sites with less 2003. summer precipitation than other Chrysolina spp. It is best suited for maritime ocean climates and dry continental habitats. Abundant Harris, P. and D. P. Peschken. 1971. 32. Hypericum perforatum L., St. populations are found in Mediterranean type habitats. It requires John's wort (Hypericaceae). Biological Control Programmes Against open sunny locations as it is intolerant of shade. Dry summers are Insects and Weeds in Canada 1959-1968. Commonwealth necessary to avoid breaking their mandatory dormant period. Agricultural Bureaux. Pp. 90. Locations with frequent summer rains will break dormancy, effecting the agent's survival. Kelleher, J. S. and M. A. Hulme, (editors). 1984. Biological control programmes against insects and weeds in Canada 1969-1980. C. quadrigemina has the most southern native European distribution Commonwealth Agricultural Bureaux. of all the Chrysolina species released in BC. It has a range from northern Africa to Denmark (but is absent from mainland Sweden).
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Manitoba Agriculture. No date. St. John's wort (Hypericum perforatum L.). Brochure. Gov. of Man.
MFR STAFF OBSERVATIONS AND COMMENTS Powell, G. W., A. Sturko, B. Wikeem and P. Harris. 1994. Field guide to the biological control of weeds in British Columbia. B.C. Min. For. Res. Prog.
Rees, N. E., Quimbly, Jr., P. C., G. L. Piper, E. M. Coombs, C. E. Turner, N. R. Spencer, L. V. Knutson (editors). 1996. Biological control of weeds in the west.
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BIOLOGICAL CONTROL AGENT: CHRYSOLINA VARIANS (SCHALLER) was released 1957 near Westbank into a buchgrass habitat surrounded by Ponderosa pine. No evidence of the beetle was Type of agent: Foliar feeding beetle found the following year and it was presumed the site was too dry Status: Tertiary to support this Chrysolina species. The area has undergone significant development since the release. In 1958 another release Invasive Plant Species Attacked: was made into an area dominated by Interior Douglas-fir and short St. John's wort term establishment was found. (Hypericum perforatum) Habitat: DESCRIPTION AND BIOLOGY C. varians was released into the Bunchgrass and Interior Douglas-fir Adult: biogeoclimatic zones. Early monitoring determined it did not The beetles are metallic bronze, establish and it was indicated that the sites may be too dry. brown or greenish coloured. Bunchgrass and Ponderosa pines biogeoclimatic zones are probably Adults emerge in early June and begin feeding in clusters on young not favourable for this particular species. terminal leaves, flower buds or the underside of leaves (May to September in Europe). They continue to feed until leaf drop in July Field results: and early August. Reproduction is related to day length, with longer Historical records indicate that the second C. varians release in only daylight, less feeding and reproduction occurs. This changes when survived one winter. A few beetles were found one year later, but day length is reduced. At this time they move into plant litter and no further evidence was found in subsequent years. If it did await the fall rains. Once precipitation breaks dormancy, mating and establish long term, it may now be found only in mixed populations egg-laying begins. Females oviposit eggs individually or in small with two other Chrysolina species. clusters on winter basal leaves. Collection for redistribution Egg: By early June, adults can be swept when they cluster on the plants. The elongated, 1.2 mm x 0.5 mm orange eggs overwinter and hatch the following spring. The eggs incubate for 6 - 7 days. NOTES C. varians is similar to the other Chrysolina species released in Larva and pupa: BC making identification difficult in the absence of the other The plump, humped-back larvae, initially orange coloured, change species for comparison. to dirty pink-grey as they mature. The eggs that have overwintered usually hatch in May. The new larvae feed on buds and immature REFERENCES leaves causing complete defoliation before moving on to adjacent Harris, P. 2003. Classical biological control of weeds established plants. Feeding on St. John's wort causes the larvae to become light biocontrol agent Chrysolina hyperici (Forst.). Defoliating beetle. Gov. sensitive. Photosensitivity prevents them from feeding during the of Can., Agriculture and Agri-Food Canada. May 20, 2003. day, therefore they must feed during low light periods, and do so
before sunrise. After the morning feed they seek shade and Harris, P. 2003. Classical biological control of weeds established protection, the smallest hide in leaf buds while the larger ones move biocontrol agent Chrysolina quadrigemina (Suffr.). Defoliating under the plants or into the soil. They resume feeding at sunset. beetle. Gov. of Can., Agriculture and Agri-Food Canada. May 20, Mature larvae burrow into the soil during spring and early summer 2003. and create a pupal cell.
Harris, P. and D. P. Peschken. 1971. 32. Hypericum perforatum L., St. Overwintering stage: John's wort (Hypericaceae). Biological Control Programmes Against Overwinters in egg form on fall/winter basal leaves. Insects and Weeds in Canada 1959-1968. Commonwealth
Agricultural Bureaux. Pp. 90. LOCATION AND EFFECTIVENESS OF ATTACK Early spring larvae feeding on fleshy new growth cause the most Kelleher, J. S. and M. A. Hulme, (editors). 1984. Biological control damage. Although adult feeding can be impressive, it has less programmes against insects and weeds in Canada 1969-1980. impact than early larvae feeding. Heavy fall feeding may cause some Commonwealth Agricultural Bureaux. impact on the plants ability to overwinter. Manitoba Agriculture. No date. St. John's wort (Hypericum PREDICTED AND NATIVE HABITAT perforatum L.). Brochure. Gov. of Man. Chrysolina varians habitat appears narrower than other Chrysolina species. It may be best suited for maritime climates. It does not MFR FIELD OBSERVATIONS AND COMMENTS. tolerate hot dry conditions. It requires soft soils for pupation; Powell, G. W., A. Sturko, B. Wikeem and P. Harris. 1994. Field guide avoiding sites which are rocky or barren. As with other Chrysolina it to the biological control of weeds in British Columbia. B.C. Min. For. requires open sunny locations; avoiding shaded and forested areas. Res. Prog.
Its native distribution is from Spain to west Siberia. C. varians occurs Rees, N. E., Quimbly, Jr., P. C., G. L. Piper, E. M. Coombs, C. E. in northern and alpine areas of Europe. It is common where Turner, N. R. Spencer, L. V. Knutson (editors). 1996. Biological summers are moist. In harsh winter habitat it requires sufficient control of weeds in the west. snow cover for protection. In Sweden it is found abundantly in moist forest openings and at sites with low canopy bushes.
BRITISH COLUMBIA EXPERIENCES Origin: C. varians stock originated from Sweden.
History: C. varians was one of the three Chrysolina species introduced to BC. A pure population
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BIOLOGICAL CONTROL AGENT: CYPHOCLEONUS ACHATES (FAHR.) Once new weevils leave the root, their exit holes allow an entry point for secondary attacking pathogens. Type of agent: Root feeding beetle (weevil) Status: Secondary PREDICTED AND NATIVE HABITAT
C. achates prefers hot and dry habitat, with loose, well drained Invasive Plant Species Attacked: coarse soils. It establishes in undisturbed bunchgrass habitat, Spotted knapweed (Centaurea biebersteinii) favouring bare soil surfaces where grasses do not crowd the target Diffuse knapweed (C. diffusa) plants. It shows a preference for spotted knapweed over diffuse
knapweed. Sites need to be somewhat large with a corridor of Operational Field Guide: plants for it to disperse to by walking. Cyphocleonus achates -
Operational Field Guide, Its native distribution includes areas in eastern and southern Europe Ministry of Forests and and Asia Minor. It is found in the former Czechoslovakia, Austria, Range Hungary, Romania, Bulgaria, Greece, Turkey, Syria and the former
USSR. DESCRIPTION AND BIOLOGY Adult: BRITISH COLUMBIA EXPERIENCES The weevils measure 0.8 - Origin: 1.75 cm and at first have C. achates released in BC originate from Austria, Hungary and dark reddish-brown soft bodies. In a few days their bodies harden Romania. and they become grey-brown. Their colouring allows them to
camouflage on dried plants, floral bracts and soils. Females have a History: rounded abdomen while the males are flattened. They are rapid C. achates was first introduced to BC in 1987. This first shipment walkers which compensates for their inability to fly. Adults emerge was released into rearing tents in Kamloops, open rearing plots at from roots in mid July; peak in August, then taper off into Castlegar and a field release in the south Okanagan. In 1988, an September. The earliest quantity of emerging weevils has a higher open field release made in Kamloops became a collection source in ratio of males, later the ratio becomes equal, and near the end of 1991. Over time several sites became premium collection sources, the season more females are present. Mating begins within one or producing thousands of adults for redistribution. In 10 years (1987 - two weeks of emergence and egg-laying begins in August. Females 1997) 18,487 weevils had been collected for redistribution. In 1996, mate repeatedly and oviposit an average of 45 eggs over their entire BC shipped 529 weevils to Brocket, Alberta for a field release, but 10 week life span. The procedure to lay each egg takes about 25 there has been no further contact to determine the status of this minutes to complete. Females excavate head first, 10 - 20 mm into site. Assisted redistribution is still ongoing in BC. soft soil and chew an attachment location on the plant crown. Then
they back out and reverse into the site to deposit a single egg, Habitat: cementing it in place with soil particles. Usually the females will fill C. achates has been released into the Bunchgrass, Coastal Douglas- the excavation before moving on to repeat the process. If the fir, Coastal western hemlock, Engelmann spruce-subalpine-fir, females do not backfill, another female will often use the prepared Interior cedar-hemlock, Interior Douglas-fir, Montane spruce, site to oviposit another egg. Ponderosa pine, and Sub-boreal spruce biogeoclimatic zones. C.
achates is found established and dispersed in all these zones except Egg: the Montane spruce and Sub-boreal spruce. The oval eggs are 1.76 x 1.24 mm. Initially, they are white or pale
yellow and darken during incubation, which takes 10 - 12 days. Field results:
C. achates successfully establishes with other bioagents, however Larva and pupa: when competition becomes heavy, its population density seems to The larvae are plump, creamy white decline. It has been found co-existing in sites with three other root or yellowish, with large, light brown feeders: Agapeta zoegana, Pterolonche inspersa and Sphenoptera head capsules. Similar to most jugoslavica , as well as with the seed feeders - Larinus minutus, L. weevils, they retain a "C" shape. obtusus, Urophora affinis, U. quadrifasciata and Metzneria There are four larval instars. Upon paucipunctella, and the stem/leaf rust Puccinia jaceae. C. achates hatching, new larvae mine inward to mating is not observed before the first week of August, and egg- the root core. The first two instars feed within roots until fall and laying follows in the third week. then rest overwinter and resume feeding the following spring. Third
and fourth instar causes the root to swell and enlarge. Several larvae Collection for redistribution on one root create large linked formations, 2 - 4 cm long x 1 cm Hand picking adults off plants allows for the immediate sorting of wide. Pupation occurs in late spring or early summer, lasting about sexes if required. If collection occurs when the sex ratio is in favour two weeks. New adult weevils chew through the root and crawl to of the males, efforts are not as efficient as release sites will not the surface. receive as many ovipositing females. Collection is best done when
the ratio is either equivalent or favours the females. Care must be Overwintering stage: taken, however to not collect too late in their season as females Second instar larvae overwinter in the root. would have already laid their eggs. Hand collecting is rapid and
successful once the technique and weevil behaviour is learned. LOCATION AND EFFECTIVENESS OF ATTACK Adults congregate on host plants and other vegetation, often in Larvae mine the plant roots which notably pairs. Shadows and plant disturbance causes them to drop and feign reduce the plants ability to dispense energy death. They will move away from potential danger by moving used to produce shoot growth. Studies indicate that two behind stems and circling out of view. Sweeping for adults can be larvae/spotted knapweed rosette reduces shoot biomass by 65%. done, but increases the chance of damaging the adults. Larvae feeding cause plants to become shortened, producing fewer flowers and less seeds. Adult feeding on leaves, especially young NOTES leaves, reduces plant vigour. As plants become smaller or die, more C. achates can exist with A. zoegana and the two work better soil surface becomes exposed, increasing heat absorption which in conjunction than on their own. A. zoegana prefers dense further enhances Cyphocleonus achates - preferred environment. 13 | P a g e
knapweed stands and their attack decreases the plant size, which exposes more soil surface, which results in higher soil temperatures and preferred C. achates habitat.
REFERENCES Harris, P. 2005. Classical biological control of weeds established biocontrol agent Cyphocleonus achates (Fahr.). Root-core weevil. Gov. of Can., Agricul. Agri-Food Canada. February 7, 2007.
Mason, P. G. and J. T. Huber, (editors). 2002. Biological control programmes in Canada, 1981-2000. CAB International.
MFR STAFF OBSERVATIONS AND COMMENTS Powell, G. W., A. Sturko, B. Wikeem and P. Harris. 1994. Field guide to the biological control of weeds in British Columbia. B.C. Min. For. Res. Prog.
Province of British Columbia. 1998. Operational field guide to the propagation and establishment of the bioagent Cyphocleonus achates (knapweed root weevil). Min. For., For. Practices Br., Range Sec., Noxious Weed Control Program. 30 p.
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BIOLOGICAL CONTROL AGENT: GALERUCELLA CALMARIENSIS (L.) following growing season. Sites with high larvae densities will cause defoliation by the end of July. Type of agent: Foliar feeding beetle Status: Secondary PREDICTED AND NATIVE HABITAT
G. calmariensis tolerates varying habitats where purple loosestrife Invasive Plant Species Attacked: grows. It is tolerant of flooding, but continual flooding may not Purple loosestrife suitable. For that reason, sites with a moisture gradient will offer (Lythrum salicaria L.) alternative locations of choice habitat. They appear to prefer areas
on the margins of wet lands. Galerucella beetles prefer full sun and, DESCRIPTION AND BIOLOGY therefore, locations with sun exposure will be preferred over Adult: shaded or partially shaded sites. Adults are 3 - 5 mm long, tan coloured with a dark In its native environment, G. calmariensis occurs in varying climates band appearing along the within wide ranging ecological habitats. Field surveys indicate their margin of their wing-cover range to be in central and north European countries, for example in and with a triangular mark behind their head. Overwintered adults south Sweden and Finland and to the south to north Africa, and with appear in mid May into early June, usually when the plants are 20 recorded sightings in Siberia, Kazakhstan and central Asia. When G. cm tall, and begin feeding on the plant buds and tender new calmariensis and G. pusilla habitats overlap, G. calmariensis occurs growth. Females will oviposit within the first week of emergence when the plants are growing in higher densities. beginning in June, peaking about mid month then slowing after the summer solstice and continuing into July. They will lay a few eggs BRITISH COLUMBIA EXPERIENCES and then disperse. Repeated mating is required for viable eggs. The Origin: eggs are laid in small masses of 1 - 36 (average eight) on the lower G. calmariensis populations released in BC originate from Germany. parts of the plant stems and are covered with a strip of black faecal
material. Over their life, females can lay between 300 and 400 eggs. History: Egg-laying is heaviest (about 10/day) when temperatures are over The first G. calmariensis treatment in British Columbia was made in 250C, this reduces when the temperature lowers to 200C. Adults 1993 in the Fraser Valley. Since populations are routinely considered disperse well and their mobility enables them to readily seek new mixed with G. pusilla, it is possible both species occur on most, if not plant sites. all, sites.
The second generation are more prone to dispersal than those that Habitat: overwinter and emerge in the spring. Adults emerging in July will Galerucella spp. treatments have been made into Bunchgrass, mate and oviposit within a week and lay eggs for one month and Coastal western hemlock, Coastal Douglas-fir, and Interior cedar- those that appear later may breed, but will not oviposit before they hemlock biogeoclimatic zones. All zones have shown establishment. hibernate. For two months parent and F1 generation adults are both
present, with their oviposition periods overlapping for one month. Field results: Adults that emerge and lay to produce the first generation will die Impressive feeding damage can be by the end of summer. In the habitats with two generations, some found within coastal and interior of the adults will lay a few eggs in late summer and early fall, prior sites from mid-summer onward. On to their hibernation. The duration from egg to adult is 30 - 40 days. long linear sites, plants are failing to
produce flowers near the immediate Egg: release point. In the interior, adults The creamy-white, 1 mm diameter, spherical eggs incubate for 12 can be observed from July into early days. August, and the seasons' abundant
feeding is evident in early Larva and pupa: September. In the lower mainland, adults and egg masses were seen Larvae are pale yellow. There are three instars and all are similar from mid May through June. Adults were collected from the lower with no distinguishing changes. The youngest larvae feed primarily mainland in June well within the incoming tide level showing their on young buds and leaves on the upper most part of stems. Soon tolerance for wet sites. In BC, two generations are normal. after, they feed on the undersides of larger leaves. Since this species Galerucella spp. treatment sites in the lower mainland now have emerges earlier than Galerucella pusilla , it will destroy fewer buds. low plant densities and reduced flowering, which have negatively After 14 days the mature larvae will be 3 - 5 mm long and pupation impacted seed production. This same success is starting to show in is then initiated. Pupation normally occurs in the soil. However at the southern interior. sites which flood, pupation takes place in the plant stems above the
water level. The new adults will remain on the soil or lower stems Collection for redistribution for two days until their bodies become hardened and then appear Transfers can be successfully done by moving plant material with on the upper plant parts. larvae into new locations or adults can be aspirated from plants
during peak periods. When treatments are made with small Overwintering stage: numbers of beetles released, small populations will usually Adults overwinter in the soil near the surface. Hibernation is continue, therefore large releases perform best. controlled by temperature.
NOTES LOCATION AND EFFECTIVENESS OF ATTACK By combining the two Galerucella spp., benefits are gained. G. Larvae and adult feeding on buds will stunt plants and reduce seed calmariensis feeds on early plant growth, causing the plants to production. In heavy populations, plants will be destroyed. The send out new shoots that then coincide with G. pusilla feeding spring emerging adults attack early growth, impacting the plants' requirements. ability to photosynthesize and restore nutrients. Reduced flowering DNA of these closely related species have been studied and and seed production is common after several years attack. Delayed demonstrate a distinct reproductive separation. flowering by one month also reduces the number of flowers the
plant can produce and later blooming limits pollination. Repeated heavy defoliation and attack will reduce the plants' vigour the REFERENCES 15 | P a g e
Blossey, B. and D. Schroeder. 1991. Study and screening of potential biological control agents of purple loosestrife (Lythrum salicaria L.). Internat. Instit. Biol. Control, European Station, Delemont, Switzerland. Final Report. 41 p.
Corrigan, J. and P. Harris. 2003. Classical biological control of weeds established biocontrol agent Galerucella calmariensis (L.) and G. pusilla (Duft.). Defoliating beetles. May 20, 2003
Mason, P. G. and J. T. Huber, (editors). 2002. Biological control programmes in Canada, 1981-2000. CAB International.
MFR STAFF FIELD OBSERVATIONS AND COMMENTS. Powell, G. W., A. Sturko, B. Wikeem and P. Harris. 1994. Field guide to the biological control of weeds in British Columbia. B.C. Min. For. Res. Prog.
Rees, N. E., Quimbly, Jr., P. C., G. L. Piper, E. M. Coombs, C. E. Turner, N. R. Spencer, L. V. Knutson (editors). 1996. Biological control of weeds in the west.
Wilson, Linda M., Mark Schwarzlaender, Bernd Blossey, and Carol Bell Randall. No date. Biology and biological control of purple loosestrife. Wash. State Univers. & Oregon Dept. of Agric. 78 p.
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BIOLOGICAL CONTROL AGENT: GALERUCELLA PUSILLA (DUFT.). suitable. For that reason, sites with a moisture gradient will offer alternative locations of choice habitat. They appear to prefer areas Type of agent: Foliar feeding beetle on the margins of wet lands. Galerucella beetles prefer full sun and, Status: Secondary therefore, locations with sun exposure will be preferred over shaded or partially shaded sites. Invasive Plant Species Attacked: Purple loosestrife (Lythrum salicaria L.) In its native environment, G. pusilla occurs in varying climates within wide ranging ecological habitats. Field surveys indicate their range DESCRIPTION AND BIOLOGY to be in central and north European countries, and is found in south Adult: Sweden and Finland and to the south to north Africa, and with The adults are 3 - 5 mm long, light golden-brown and lack the dark recorded sightings in Siberia, Kazakhstan and central Asia. When G. coloured wing margins found on Galerucella calmariensis. pusilla and G. calmariensis habitats overlap, G. pusilla occurs when Overwintered adults appear one week later than G. calmariensis, the plants are growing in lower densities. usually in late May to early June when the plants are 20 cm tall. Adults first feed on young shoots and new budding leaves before BRITISH COLUMBIA EXPERIENCES feeding on mature leaves. Oviposition starts within one week of Origin: adult emergence, beginning in June, peaking around mid month G. pusilla populations released in BC originate from Germany. then slowing after the summer solstice and continuing into July. Repeated mating is necessary for viable eggs. The females usually History: lay the eggs in masses of three on lower parts of plant stems and The first G. pusilla treatment in British Columbia was made in 1994 cover them with a strip of black faecal material. Egg-laying is on Vancouver Island. Before its establishment could be confirmed, 0 heaviest when temperatures are over 25 C. G. pusilla is strongly the site was destroyed by development. Another G. pusilla affected by low temperatures during oviposition. Over their life, the population was later released into the southern interior and adults females will lay between 300 and 400 eggs. G. pusilla disperses less were located in 2001 and 2002. However at this location the than G. calmariensis and therefore creates a local dense population collections are suspected to now be mixed Galerucella spp. before moving to new locations. populations. Since populations are routinely considered mixed, it is possible both species occur on most, if not all, sites. The second generation are more prone to dispersal than those that overwinter and emerge in the spring. Adults emerging in July will Habitat: mate and oviposit within a week and lay eggs for one month and Treatments have been made into Bunchgrass, Coastal Douglas-fir, those that appear later may breed, but will not oviposit before they Coastal western hemlock, and Interior cedar-hemlock hibernate. For two months parent and F1 generation adults are both biogeoclimatic zones and all zones have shown establishment. present, with their oviposition periods overlapping for one month. Adults that emerge and lay to produce the first generation will die Field results: by the end of summer. The duration from egg to adult is 24 days at Impressive feeding damage can be found within coastal and interior 0 25 C. sites from mid-summer onward. On long linear sites, plants are failing to produce flowers near the immediate release point. In the Egg: interior, adults can be observed from July into early August, and the Creamy-white, 1 mm diameter, spherical eggs incubate for 12 days. seasons' abundant feeding is evident in early September. In the lower mainland, adults and egg masses were seen from mid May Larva and pupa: through June. Adults were collected from the lower mainland in The larvae are pale yellow coloured. There are three instars, all are June well within the incoming tide level showing their tolerance for similar and have no distinguishing changes. Upon hatching, new wet sites. In BC, two generations are normal. Galerucella spp. larvae move to the leaf buds and flowers concentrating on young treatment sites in the lower mainland now have low plant densities foliage before moving onto older leaves. After 14 days the mature and reduced flowering, which have negatively impacted seed larvae will be 3 - 5 mm long and pupation is initiated. The pupae are production. This same success is starting to show in the southern light brown, 3 - 5 mm long, and will complete pupation in seven interior. days in the top 3 cm of soil. However at sites which flood, pupation takes place in the plant stems above the water level. The new adults Collection for redistribution will remain on the soil or lower stems for two days until their bodies Transfers can be successfully done by moving plant material with become hardened and then appear on the upper plant parts. larvae into new locations or adults can be aspirated from plants during peak periods. When treatments are made with small Overwintering stage: numbers of beetles released, small populations will usually Adults overwinter in the soil near the surface. Hibernation is continue, therefore large releases perform best. controlled by temperature.
NOTES LOCATION AND EFFECTIVENESS OF ATTACK By combining the two Galerucella species, benefits are gained. Larvae and adult feeding on buds will stunt plants and reduce seed G. calmariensis feeds on early plant growths causing the plants production. In heavy populations, plants will be destroyed. The to send out new shoots that then coincide with G. pusilla's spring emerging adults attack early growth, impacting the plants' feeding requirements. ability to photosynthesize and restore nutrients. Reduced flowering DNA of these closely related species have been studied and and seed production is common after several years attack. Delayed demonstrate a distinct reproductive separation. flowering by one month also reduces the number of flowers the plant can produce and later blooming limits pollination. Repeated REFERENCES heavy defoliation and attack will reduce the plants vigour the Blossey, B. and D. Schroeder. 1991. Study and screening of potential following growing season. Sites with high larvae densities will cause biological control agents of purple loosestrife (Lythrum salicaria L.) defoliation by the end of July. Internat. Instit. Biol. Control, European Station, Delemont,
Switzerland. Final Report. 41 p. PREDICTED AND NATIVE HABITAT G. pusilla tolerates a variety of habitats where purple loosestrife grows. It can tolerate flooding, but continual flooding may not 17 | P a g e
Corrigan, J. and P. Harris. 2003. Classical biological control of weeds established biocontrol agent Galerucella calmariensis (L.) and G. pusilla (Duft.). Defoliating beetles. May 20, 2003
Mason, P. G. and J. T. Huber, (editors). 2002. Biological control programmes in Canada, 1981-2000. CAB International.
MFR STAFF FIELD OBSERVATIONS AND COMMENTS. Powell, G. W., A. Sturko, B. Wikeem and P. Harris. 1994. Field guide to the biological control of weeds in British Columbia. B.C. Min. For. Res. Prog.
Rees, N. E., Quimbly, Jr., P. C., G. L. Piper, E. M. Coombs, C. E. Turner, N. R. Spencer, L. V. Knutson (editors). 1996. Biological control of weeds in the west.
Wilson, Linda M., Mark Schwarzlaender, Bernd Blossey, and Carol Bell Randall. No date. Biology and biological control of purple loosestrife. Wash. State Univers. and Oregon Dept. of Agric. 78 p.
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BIOLOGICAL CONTROL AGENT: LARINUS MINUTUS GYLL. Larvae feeding in flowers cause significant decreased seed production. In trials L. minutus is the main seed feeder and creates Type of Agent: Seed feeding beetle (weevil) the most impact. Status: Secondary
PREDICTED AND NATIVE HABITAT Invasive Plant Species Attacked: Typically Larinus minutus prefers dryer sites with higher Spotted knapweed (Centaurea biebersteinii), temperatures than those tolerated by L. obtusus. It favours dense Diffuse knapweed (C. diffusa), knapweed stands with little plant competition. It requires well Meadow knapweed (C. debeuxii) drained, coarse soils; avoiding compacted sites. Open areas with
south aspects at elevations between 300 and 800 have proven Operational Field Guide: successful. Larinus spp. is the last of the seed feeding biocontrol Larinus minutus - Operational Field Guide, Ministry of Forests and agents to oviposit and competing agents can limit its success. Range
Its native geographical distribution is from Bulgaria, Greece, Israel, DESCRIPTION AND BIOLOGY Rumania, Caucasus Mountains, Kazakhstan, and southern western Adult: parts of the former USSR. Weevils are 5 - 10 mm long, mottled rusty BRITISH COLUMBIA EXPERIENCES brown, with a line of Origin: short yellowish hairs The L. minutus populations released in BC originate from Greece. on their wing covers.
Their rostrum (nose) is History: short, bent and blunt. L. minutus was approved for release in North America in 1990 and in They are strong fliers 1991 the first adults were shipped to BC. The first shipment was and readily take flight divided into several southern interior field releases and the rearing on hot days. facility in Kamloops. That same year, a second generation was Overwintered adults collected from the propagation tent and released near Castlegar. In emerge in late spring before the plants have set bud and feed on 1994, field sites began to produce enough adults to become foliage, stems and seedlings. Females require sufficient feeding on collection sources. Assisted redistribution is still ongoing and may knapweed to develop mature ovaries. Mating occurs from late occur in mixed populations withL. obtusus. In 1999, L. minutus was morning through mid afternoon, beginning from the onset of the designated secondary status. flowering period (usually four weeks after emergence). Females
oviposit into fresh flowers that have just opened. They chew holes Field results: in the center of the bud, damaging 3 - 4 florets, and lay a single egg From 1994 to 1998, there were 78,766 adults collected from field which they cover with a protective secretion. If the flower is large sites for redistribution. L. minutus and/or L. obtusus are observed enough to support more larvae, the females will lay up to three eggs widespread in the southern interior knapweed habitats. in diffuse and five eggs into spotted. An average of 130 eggs is laid
over seven weeks, usually depositing seven eggs each day. Their life Habitat: span is 97 days for males and 58 days for females. Although males L. minutus has been released into the Bunchgrass, Boreal white and appear to have a longer life span, more females are found in the black spruce, Coastal Douglas-fir, Coastal western hemlock, field during knapweed flowering. Some adults will hibernate a Englelmann spruce-subalpine fir, Interior cedar hemlock, Interior second year, but it is not known if they will reproduce the following Douglas-fir, Montane spruce, Ponderosa pine, and Sub-boreal summer. In part of their native range in Greece, they avoid extreme spruce biogeoclimatic zones. Establishment and/or dispersal has high mid day temperatures, seeking shade and moving onto lower been confirmed in all the zones it was released into except the plant parts. Boreal white and black spruce zone.
Egg: Collection for redistribution Eggs are yellow, oval shaped and measure 1.28 x 0.84 mm. They Sweeping for adults during peak emergence, from June to late July, require a minimum 130C for development. At 320C they hatch in 1.5 on hot days is rapid and effective. Use heavy sweepnet bags and days and at 250C they will take 2.5 days. aspirate clean collections as the adults climb towards the top
opening. On hot bright days adults take flight quickly. When females Larva and pupa: are actively ovipositing, they will cling tenaciously to the plant. Care Larvae are small, white, slightly yellow and "C" shaped, with light must be taken not to harm them when sweeping. It is best to collect brown heads. There are three instars that complete development L. minutus before this time so one can be assured the females within the flower. Head capsule measurements are used to transported to new sites will have eggs to establish a new determine each instar. Newly hatched larvae feed on pappus. At this population. early stage, multiple larvae will compete against each other, killing
off others until a number is achieved that the bud can support. The larvae mature in 17 days. They pupate in spotted knapweed in an NOTES upright, hard cocoon, 5 - 8 mm x 8 - 9 mm. In diffuse knapweed the L. minutus can co-exist with Urophora affinis because the fly cocoon is lighter weight or absent. Pupation lasts nine days and new attacks the plants earlier and is shielded with a protective gall. adults emerge by chewing through the pupal case, moving upward It does however avoid using the same buds. and out and leaving behind a dark cavity. A variation in adult size is a direct result of competition for food during the larval development stage. Overwintering stage: Adults overwinter in cracks and crevices in the soil and in plant REFERENCES litter. Groppe, K. 1990. Larinus minutus Gyll. (Coleoptera: Curculionidae), a suitable candidate for the biological control of diffuse and spotted LOCATION AND EFFECTIVENESS OF ATTACK knapweed in North America. C.A.B. Internat. Instit. Biol. Contr., European Station Rep. 31 p.
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Harris, P. 2007. Classical biological control of weeds established biocontrol agent Larinus obtusus Gyll. soft - achene feeding weevil. Gov. of Can., Agriculture and Agri-Food Canada. February 7, 2007.
Mason, P. G. and J. T. Huber, (editors). 2002. Biological control programmes in Canada, 1981-2000. CAB International.
MFR STAFF OBSERVATIONS AND COMMENTS Powell, G. W., A. Sturko, B. Wikeem and P. Harris. 1994. Field guide to the biological control of weeds in British Columbia. B.C. Min. For. Res. Prog.
Province of British Columbia. 1999. Operational field guide to the propagation and establishment of the bioagent Larinus minutus (Knapweed seedhead weevil). Min. For., For. Practices Br., Range Sect., Noxious Weed Control Program.
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BIOLOGICAL CONTROL AGENT: LARINUS OBTUSUS GY Adults overwinter in cracks and crevices in the soil and in plant litter. Type of Agent: Seed feeding beetle (weevil) Status: Secondary LOCATION AND EFFECTIVENESS OF ATTACK
Larvae feeding in flowers cause significant decreased seed Invasive Plant Species Attacked: production. Spotted knapweed
(Centaurea biebersteinii), Diffuse knapweed PREDICTED AND NATIVE HABITAT (C. diffusa), Larinus obtusus shares similar habitat requirements as L. minutus, Brown knapweed attacking several knapweeds, but shows a preference for spotted (C. jaceae), knapweed. It favours moister sites with lower temperatures than Black knapweed those tolerated by L. minutus. It establishes on south and west (C. nigra), slopes with well drained coarse soils, often near water. Excess Short-fringed knapweed competing vegetation may discourage establishment. (C. nigrescens), Meadow knapweed Its native geographic distribution is from Central Europe east to the (C. debeuxii) Caucasus mountain region.
Operational Field Guide BRITISH COLUMBIA EXPERIENCES Larinus obtusus - Operational Field Guide, Ministry of Forests and Origin: Range The L. obutus releases in BC originate from Romania.
DESCRIPTION AND BIOLOGY History: Adult: L. obtusus was first introduced to open field releases in 1992 and Weevils are 4.5 - 6.5 mm long, mottled brown-black coloured with a 1993 in the southern interior. While the sites in the Kootenays line of short yellowish hairs on their wing covers. Their rostrum established, others did not. Subsequent releases made have (nose) is short, bent and blunt. They are strong fliers and readily established and the weevils have dispersed. Assisted redistribution take flight on hot days. Overwintered adults emerge in late spring is still ongoing and may occur in mixed populations with L. minutus. before the plants have set bud and feed on foliage, stems and In 2002, L. obtusus was designated secondary status. seedlings. Females require sufficient feeding on knapweed to develop mature ovaries. Mating occurs from late morning through Habitat: to mid afternoon, beginning from the onset of the flowering period L. obtusus has been released into the Bunchgrass, Coastal Douglas- (usually four weeks after emergence). Females oviposit into fresh fir, Coastal western hemlock, Engelmann spruce-subalpine fir, flowers that have just opened. They chew holes into the center of Interior cedar hemlock, Interior Douglas-fir, Montane spruce, the bud, damaging 3 - 4 florets and lay a single egg which they then Ponderosa pine and Sub-boreal spruce biogeoclimatic zones. cover with a protective secretion. If the flower is large enough to Establishment and/or dispersal has been confirmed in all zones support more larvae, the females will lay up to five eggs into except in the Sub-boreal spruce zone. spotted knapweed. An average of 130 eggs are laid over seven weeks, usually at a rate of seven eggs per day. Their life span is 97 Field results: days for males and 58 days for females. Although males have a In 1999, 14,800 adults were field collected from the Nelson area and longer life span, more females are found in the field during redistributed. Of the 33 new sites, 29 established within a single knapweed flowering. Some adults will hibernate a second year, but year. L. obtusus and/or L. minutus are observed widespread in the it is not known if they will reproduce the following summer. southern interior knapweed habitats. L. obtusus has also established on meadow knapweed and short-fringed knapweed in BC. It does Egg: not establish on diffuse knapweed, which grows in an unfavourable Eggs are yellow, oval, and measure 1.28 x 0.84 mm. They require a habitat. minimum temperature of 130C for development. At 320C they hatch in 1.5 days and at 250C they take 2.5 days. Collection for redistribution Sweeping for adults during peak emergence, from June to late July, Larva and pupa: on hot days is rapid and effective. Use heavy sweepnet bags and Larvae are small white, aspirate clean collections as the adults climb towards the top slightly yellow and "C" opening. On hot bright days adults take flight quickly. When females shaped, with light brown are actively ovipositing, they will cling tenaciously to the plant. Care heads. There are three must be taken not to harm them when sweeping. It is best to collect larval instars that complete L. obtusus before this time so one can be assured the females develop within the flower. transported to new sites will have eggs to establish a new Head capsule measurement population. is used to determine each instar. Newly hatched NOTES larvae feed on pappus. At L. obtusus can exist with Urophora affini because the fly this early stage, multiple attacks the plants earlier and is shielded with a protective gall. larvae will complete against each other, killing others until a number It does, however avoid using the same buds. is achieved that the bud can support. Larvae mature in 17 days. It is the last of the seed feeding agents to oviposit and They pupate in an upright hard cocoon, 5 - 8 mm x 8 - 9 mm. competing agents can limit its success. Pupation lasts nine days and new adults emerge by chewing through the pupal case, moving upward and out and leaving behind a dark cavity. They browse on plant foliage until hibernation. REFERENCES
Overwintering stage:
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Groppe, K. 1992. Larinus obtusus Gyll. (Col.: Curculionide). A candidate for biological control of diffuse and spotted knapweed. C.A.B. Internat. Inst. Biol. Contr. Final Report. 46 p.
Harris, P. 2007. Classical biological control of weeds established biocontrol agent Larinus obtusus Gyll. soft - achene feeding weevil. Gov. of Can., Agriculture and Agri-Food Canada. February 7, 2007.
Mason, P. G. and J. T. Huber, (editors). 2002. Biological control programmes in Canada, 1981-2000. CAB International.
MFR STAFF OBSERVATIONS AND COMMENTS Powell, G. W., A. Sturko, B. Wikeem and P. Harris. 1994. Field guide to the biological control of weeds in British Columbia. B.C. Min. For. Res. Prog.
Rees, N. E., Quimbly, Jr., P. C., G. L. Piper, E. M. Coombs, C. E. Turner, N. R. Spencer, L. V. Knutson (editors). 1996. Biological control of weeds in the west.
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BIOLOGICAL CONTROL AGENT: LARINUS PLANUS (F.) L. planus is capable of inhabiting wide geographic areas where Canada thistle exists. It prefers the dryer range of the invasive Type of agent: Seed feeding beetle (weevil) plant's habitat, however it adapts and slowly increases at moist Status: Secondary sites. It prefers open sunny sites with coarse or well drained soils. Shaded locations or sites that flood or acquire water pooling are not Invasive Plant Species Attacked: ideal. Areas that are mowed or receive irrigation discourage Canada thistle establishment. It feeds on several thistles, but it prefers Canada (Cirsium arvense) thistle over others. Plumeless thistle (Carduus acanthoides). The native distribution occurs in southwest England and throughout Europe is commonly found in Morocco, Asia Minor, Caucasus Adult foliar feeding on Mountains, and central Asia. It is absent in central and northern Bull thistle Scandinavia. (Cirsium vulgare) Nodding thistle BRITISH COLUMBIA EXPERIENCES (Cirsium nutans). Origin:
L. planus releases in BC originate from adventive populations found Operational Field Guide: in 1988 in the Fraser Valley. This native European insect found its Larinus planus - Operational Field Guide, Ministry of Forests and way to North America before 1968. Range
History: DESCRIPTION AND BIOLOGY In 1988 L. planus was discovered in Burnaby. As a result of these Adult: findings, screening commenced and was completed in Alberta. Weevils are oval shaped, 5 - 10 mm long. Wing covers are slightly Approval occurred in 1988 and distribution began in 1989 into the pock-marked with greyish-white tufts of hair. Their rostrum (nose) is southern interior. Assisted redistribution is still ongoing. In 2001, L. long and narrow. Adults emerge from leaf litter in mid June before planus was designated secondary status. Canada thistle has set bud and begin feeding in 2 - 3 days. Mating 0 begins when temperatures reach 22 C, which occurs with bud Habitat: formation, usually 14 - 26 days after they have emerged. Females L. planus has been released into the Bunchgrass, Boreal white and seek out flowers for prime floral buds, choosing male or female black spruce, Coastal Douglas-fir, Coastal western hemlock, flowers that fit specific criteria. Acceptable bud sizes range from 5 - Engelmann spruce-subalpine fir, Interior cedar-hemlock, Interior 7 mm, ideal is 6 mm; when buds enlarge over 7 mm they are past Douglas-fir, Montane spruce, Ponderosa pine and Sub-boreal spruce suitability. Specific size is important for larvae development and biogeoclimatic zones. It has established and/or dispersed in all these coincides with the onset of rapid bud growth. A female chews zones except the Boreal white and black spruce zone. cavities into unopened floral buds, deposits a single egg in each, and seals them with fecal material. A summer brood of adults emerge Field results: from buds in August and September, which feeds for a short time L. planus has been found browsing on bull thistle and nodding and prepare to overwinter. Adults disperse by walking or taking to thistle, however it is not known if full development occurs on these flight. plants. It has been slow to accept BC's northern climates. L. planus does not drop away and feign death as easy as most weevils. This Egg: may contribute to predation. Additionally, Canada thistle is highly " " The black pin-prick size oviposition point turns brown and an attractive to black aphids and ants which have been seen attacking obvious distorted dimple can be observed. Eggs incubate over four L. planus adults. days. Collection for redistribution Larva and pupa: Aspirate adults from plants in June. Release into new locations The larvae have segmented white which do not have a high ant population. Sites need to be exempt bodies with brown heads and typically from activities that damage or remove flower buds. are 'C' shaped. Upon hatching the larvae feed on the entire seedhead NOTES contents, consuming developing Two generations of adults are present at one time, the spring reproductive plant parts. If multiple emerged mating adults and the August summer brood. eggs are deposited in a bud, only one
larva will survive. In mid-summer pupation occurs inside a loose cocoon made from pappus and chewed bud material. New adults REFERENCES emerge through the top of the floral buds in August and September. Harris, P. 2005. Classical biological control of weeds established biocontrol agent Larinus planus (F.) (=carlinae). Flower-head weevil. Overwintering stage: Gov. of Can., Agriculture and Agri-Food Canada. February 7, 2007. The summer adults overwinter in plant litter and debris near the plants' bases. Manitoba Agriculture. 1993. Canada thistle biocontrol insect profile Canada thistle seed head weevil. Biofacts. Govt. of Manitoba. 2 p.
LOCATION AND EFFECTIVENESS OF ATTACK McClay, A. S. 1989. Biology and host specificity of Larinus planus (F.) A single larva consumes floral bud contents, destroying most or all (Coleoptera: Curculionidae), a potential agent for Canada thistle, of the seeds. Large Larinus planus populations can reduce seed Cirsium arvense (L.) Scop. Govt. of Canada, Alberta Environ. Centre. production by 95%, which is greater than other seedfeeders. Seed 28 p. reduction is most important on plumeless thistle, a biennial that
reproduces strictly by seed. Adult feeding can be quite impressive, but provides less control than the larvae. Sites require a long time to MFR STAFF OBSERVATIONS AND COMMENTS develop populations large enough to show results. Powell, G. W., A. Sturko, B. Wikeem and P. Harris. 1994. Field guide to the biological control of weeds in British Columbia. B.C. Min. For. Res. Prog. PREDICTED AND NATIVE HABITAT 23 | P a g e
Province of British Columbia. 2001. Operational field guide to the propagation and establishment of the bioagent Larinus planus (Canada thistle seed-feeing weevil). Min. For., For. Practices Br., Range Sect., Noxious Weed Control Program. 47 p.
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BIOLOGICAL CONTROL AGENT: MECINUS JANTHINUS GERMAR. Its geographic range is south and central Europe to south-western Russia, occurring between latitudes 40 and 520N. Within these Type of agent: Stem mining beetle (weevil) parameters it inhabits the sub-alpine and maritime areas associated Status: Secondary with dry summer and moist summer sub-continental climates.
Invasive Plant Species Attacked: BRITISH COLUMBIA EXPERIENCES Dalmatian toadflax Origin: (Linaria dalmatica), M. janthinus populations released in BC originate from the Rhine Narrow-leaved Dalmatian toadflax Valley in France. (L. genistifolia. dalmatica),
Yellow toadflax History: (L vulgaris) Two small populations were released in 1991. One was set into
caged rearing tents and the other was placed into an open field site Operational Field Guide: in Kamloops. Eventually the weevils were moved to open rearing Mecinus janthinus - Operational Field Guide, Ministry of Forests and plots. Subsequent weevils were collected from the rearing plots and Range later field sites developed as collection sources. The first field
collection was made in 1996. Assisted redistribution is still ongoing, DESCRIPTION AND BIOLOGY but to a lesser extent than was done in the past. In 2000, M. Adult: janthinus was designated secondary status. Black to somewhat blue coloured weevils are elongated in shape, 3.6 - 4.2 mm long, with distinct linear lines along their wing covers. Habitat: The males have strongly toothed front femurs. They emerge in May Weevils have been released and found established and/or dispersed and begin feeding on foliage, concentrating on tender terminal in the Bunchgrass, Coastal Douglas-fir, Coastal western hemlock, growth. Mating and egg-laying begins immediately, continuing until Interior cedar-hemlock, Interior Douglas-fir, Montane spruce and mid July. Females chew cavities into stems and oviposit a single egg Ponderosa pine biogeoclimatic zones. No establishment has been into each. Egg-laying continues at a rate of 1.15 eggs/day for 2.5 found at the releases made in the Boreal white and black spruce, months or more. Several eggs can be oviposited into each stem. Englemann spruce-subalpine fir, or Sub-boreal spruce zones. M. Ideal stem calliper is 0.9 mm for successful development. Prostrate janthinus known established range includes from the Canada/USA stems are not favoured. Finer stems can be oviposited into, but the border north to Terrace. larvae may fail to completely develop. Adults reared on yellow toadflax are usually smaller. Propagation results: In 1999, hundreds of bundled stems containing larvae were Egg: removed from the rearing plots and distributed throughout the 0 0 Eggs incubate for 6 - 7 days at 24 C (day) and 18 C (night). A visible province. callus forms at the oviposition site. Field results: Larva and pupa: In 1996, field collections began " " Mecinus janthinus larvae are C shaped, white larvae with pale and in 1999, 27,294 adults were brown head capsules. They require summer development collected and redistributed to 129 0 0 temperatures to be 23 - 34 days at 24 C (day) and 18 C (night). Over sites. The majority of M. 100 larvae may fully develop on a single stem, where each will mine janthinus releases have been about 1 - 3 cm length. Poor development occurs on the less made on Dalmatian toadflax. By nutritious prostrate stems. Pupae, 3.0 - 4.5 mm long, form in the 2005, M. janthinus populations stems in 30 - 40 days, changing from white to black over the were found widely dispersed, frequently seen on toadflax sites in pupation period. The following spring new adults chew the outer the southern interior. Recent observations indicate that it is also stem wall and exit through highly visible, distinct circular holes. dispersing well in the north western part of BC where less Dalmatian toadflax is established and fewer releases occur. In large Overwintering stage: populations, aggressive attack from May through June leaves the Adults overwinter in pupal cells in toadflax stems. Cold winter plants stunted, weak and unable to flower. Spring feeding causes climates cause high mortality, however sufficient populations lateral spur growths and subsequent flowers are smaller and less usually survive to continue attack the following year. productive (smaller flowers and smaller seedpods). By late August, many Dalmatian toadflax leaves are covered with a black sooty LOCATION AND EFFECTIVENESS OF ATTACK residue. M. janthinus is found more abundantly on Dalmatian than Larvae mine stems which significantly contributes to the plants' on yellow toadflax. It has been found co-existing with Rhinusa inability maintain vigour and become productive. On Dalmatian antirrhini, R. neta, R. linariae, Calophasia lunula and Brachypterolus toadflax, high populations of adult feeding prevents flowering and pulicarius. kills the upper plant stems. In these situations flowering is often delayed until the following year. Floral stalks can be reduced from Collection for redistribution several (six) to one. There is less physically noticeable impact on Aspirate adults from plants during May and June. Alternately clip yellow toadflax stands despite when seed production was reduced larvae/pupae infected stems and redistribute them among plants at by 68%. M. janthinus attack is further enhanced when plants new sites. become drought stressed. NOTES PREDICTED AND NATIVE HABITAT M. janthinus is capable of existing on the same site with other M. janthinus prefers grassland or open forested areas with hot dry seed, foliar and root feeding bioagents. conditions. Sites need to have large stemmed plants to support By 2001, M. janthinus had dispersed from Canada into larval development. The literature describes suitable areas may be Washington State. limited to the southern interior of British Columbia or Alberta. Control is enhanced in locations where plants suffer summer REFERENCES drought stress.
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Harris, P., R. DeClerck-Floate and A. McClay. 2005. Classical biological control of weeds established biocontrol agent Mecinus janthinus Germar. Stem boring weevil. Gov. of Can., Agric. and Agri- Food Canada. February 9, 2007
Mason, P. G. and J. T. Huber, (editors). 2002. Biological control programmes in Canada, 1981-2000. CAB International.
MFR STAFF OBSERVATIONS AND COMMENTS Powell, G. W., A. Sturko, B. Wikeem and P. Harris. 1994. Field guide to the biological control of weeds in British Columbia. B.C. Min. For. Res. Prog.
Rees, N. E., Quimbly, Jr., P. C., G. L. Piper, E. M. Coombs, C. E. Turner, N. R. Spencer, L. V. Knutson (editors). 1996. Biological control of weeds in the west.
Washington State. 2002. Annual report of Washington's contributing projects to cooperative regional project W-1185 (W- 185). 4 p
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BIOLOGICAL CONTROL AGENT: METZNERIA PAUCIPUNCTELLA ZELL. than each on their own. The moths' population increases five to ten times each year. Type of agent: Seed feeding moth Status: Secondary on Meadow knapweed PREDICTED AND NATIVE HABITAT Status: Tertiary on Spotted knapweed M. paucipunctella does not tolerate severe winter temperatures. Favoured sites are south slopes in dry mild winter climates. Snow Invasive Plant Species Attacked: cover during winter enhances larvae survival. It appears to do best Spotted knapweed in areas where spotted knapweed flowers early in the season. (Centaurea biebersteinii), Meadow knapweed In its native geographic range it inhabits spotted knapweed sites on (C. debeuxii) south slopes along two river systems in central Europe. Along the Danube it occurs from Svishtove, Bulgaria to east Austria with a DESCRIPTION AND BIOLOGY small local population found at Prague, Czech Republic. In the upper Adult: Rhone valley it occurs between Fully to Morel, Switzerland. The The pale brown moths are 1.0 lower Rhine valley site is restricted the La Bessee-Gourdon areas of cm long with large feathered antennae that curl upward over their France. It is also found in Granada, Spain which is outside the heads. Their wings are fringed and are held tightly to their sides and spotted knapweed range. over their backs giving them a slender appearance. Forewings are light brown and covered with dark brown specks. Adults emerge BRITISH COLUMBIA EXPERIENCES from late May to early August. Mating begins immediately and eggs Origin: are laid within 2 - 3 days after emergence. Females lay 1 - 3 eggs on M. paucipunctella populations in BC originate from the Upper Rhone the stem below the flower bud or under a floral bract on the bud. Valley, Switzerland. Females will oviposit 60 - 100 eggs during their three week lifespan. Metzneria paucipunctella does not avoid flower buds already History: attacked by Urophora spp. Adults are rarely seen during the day, M. paucipunctella was first introduced to BC into 1973, where two becoming active mainly at dusk. populations were released, one each near Castlegar and Westwold. The plants were mowed at Castlegar shortly after which contributed Egg: to poor early survival rates. By 1979 field collections commenced Eggs are oval and elongated and measure 0.75 mm. The exposed and releases continued until 1994. areas of the yellow eggs turn reddish coloured in a few days. Eggs 0 incubate for 10 - 12 days at 19 - 21 C and coincide with the opening Habitat: of the flower bud. Sources indicate, in Europe 20% of eggs become M. paucipunctella has been released and found established and/or parasitized, but this has not been observed in North America. dispersed in the Bunchgrass, Coastal Douglas-fir, Interior Cedar Hemlock, Interior Douglas-fir, Montane spruce and Ponderosa Pine Larva and pupa: biogeoclimatic zones. No establishment has been found at releases Larvae have segmented white bodies with dark brown head put in the Coastal western hemlock, Engelmann spruce-subalpine fir capsules and several pairs of legs. When mature, the larvae will or Sub-boreal spruce zones. Today M. paucipunctella widely inhabits measure 4 - 5 mm long. There are six larval instars. Emerging larvae the knapweed communities in the southern interior. Its northern enter the flower and hunt and kill competing M. paucipunctella limit is not known, the most northerly established site is at Vavenby. larvae. When only one remains, it feeds on outer florets, moulting near a central floret. The second instar larvae feed on seeds, Field results: entering one or two of them before it seals the entry hole into the At Westwold, initial sampling indicated low populations which were flower bud with silk. The third instar mines the receptacle and blamed on low winter temperatures. Intermittent sampling from becomes predatory towards other species of larvae that may be 1974 to 1980 began to show a gradual increase and by 1981 it had present. The third through the fifth instars may prey on competing dispersed 0.5 km (in seven years) from the site. On rare occasions, seed feeders notably attacking Urophora affinis. The larvae mature larvae have been found in diffuse knapweed seedheads growing at the end of their sixth instar and spin a silk tube where they among spotted knapweed. Dispersal in the central Kootenay regions overwinter. Pupation occurs the following spring inside the is reported to have achieved 40 km in 12 years. M. paucipunctella seedhead, and the silken tube provides an exit route for the new larvae were found developing within meadow knapweed seedheads adults. Larvae absorb and lose moisture, therefore the onset of in the Shuswap area. winter weather may affect their survival rate from year to year. Collection for redistribution Larvae can withstand six days at 0 Larvae/pupae can be collected by clipping stem bouquets with -21 C, but high mortality occurs intact seedheads in late summer, early fall, or early April. The when temperatures drop to - 0 infested seedheads are tied to a stake or tree at the new location. 30 C. Pupation takes about The native predatory mite, Pynotes spp., will rapidly spread through three weeks which occurs plant material stored in bulk quantities. during April and early May. The dark brown pupae casings OTES remain inside seedheads after N adults have emerged. M. paucipunctella attacks the buds after the Urophora species which will have completed their feeding, therefore, adding to Overwintering stage: the seed consumption and knapweed control. Its predation on Mature larvae overwinter in seedheads. Urophora does not appear to be a concern as both populations continue to thrive. M. paucipunctella is not competitive against Larinus spp. OCATION AND EFFECTIVENESS OF ATTACK L M. paucipunctella usually consume 8 - 9 seeds in each head, contributing to 95% of seed destruction (spotted knapweed = 9 - 10 REFERENCES seeds/head). Seed destruction may be less when larvae inhabit Harris, P. 2005. Classical biological control of weeds established extremely productive flowers. It is less effective than the two biocontrol agent Metzeria paucipuntella Zell. Achene feeder. Gov. of Urophora spp., but on a site the combination of all three is better Can., Agriculture and Agri-Food Canada. February 15, 2007. 27 | P a g e
Harris, P. and A. Muir. 1986. Biological control of spotted knapweed by Metzneria paucipunctella (Zellar). Canadex. Agric. Can. 2 p.
Mason, P. G. and J. T. Huber, (editors). 2002. Biological control programmes in Canada, 1981-2000. CAB International.
MFR STAFF OBSERVATIONS AND COMMENTS Powell, G. W., A. Sturko, B. Wikeem and P. Harris. 1994. Field guide to the biological control of weeds in British Columbia. B.C. Min. For. Res. Prog.
Rees, N. E., Quimbly, Jr., P. C., G. L. Piper, E. M. Coombs, C. E. Turner, N. R. Spencer, L. V. Knutson (editors). 1996. Biological control of weeds in the west.
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BIOLOGICAL CONTROL AGENT: MOGULONES CRUCIGER (HERBST) x 5 mm, which becomes covered with soil particles. During the summer, pupation takes 24 - 26 days. The pupal skin is shed but new Type of agent: Root feeding beetle (weevil) adults remain inside the cocoon for 10 days until their outer shell Status: Secondary hardens.
Invasive Plant Species Attacked: Overwintering stage: Hound's-tongue (Cynoglossum officinale) M. cruciger can overwinter in three forms: As mature adults in the soil (in warm climates it periodically Operational Field Guide: feeds on foliage); Mogulones cruciger - Operational Field As pupae and new adults in cocoons in the soil; and Guide, Ministry of Forests and Range As larvae in roots.
DESCRIPTION AND BIOLOGY LOCATION AND EFFECTIVENESS OF ATTACK Adult: Larvae feeding can consume all Adult weevils are round, 2 - 3 mm long, dull brown with a white parts of the underground plant cross pattern on their wing covers. Adults are capable of flying and parts. Rosettes are weakened and do so, freely dispersing to nearby invasive plant patches. They feed unable to bolt or are killed. on foliage, leaving their signature circular and oval feeding holes Reproductive plants produce over the entire leaf. shortened bolting stalks or Males and females occur on the plants at the same time of the year multiple weak bolting stalks, all with a near equal ratio. They are long-lived (1 - 2 years), during with fewer flowers. When high adult populations occur during the which females can oviposit three times. Mature overwintered spring and summer, seedlings attacked often fail to develop into females that emerge in early or late spring will have mated and productive rosettes. With larvae developing almost continuous all oviposited up to 10 eggs the preceding autumn. Their second year (except in August), plants have little opportunity to recover. oviposition period in the spring will be the main one, laying up to an additional 180 eggs. Females search for ideal oviposition locations REDICTED AND NATIVE HABITAT by walking down leaf stems into basal locations, preferring large P rosettes with large basal leaves over flowering shoots, although M. cruciger easily establishes in a wide variety of hound's-tongue floral shoots and small leaves will be used when options run low. habitat. Adults emerge in late winter and early spring, therefore, The females chew 0.5 mm wide and 1 mm deep pockets into leaf emergence dates may be somewhat affected at high elevation sites stems near the root crowns, into the shoot bases, or into the which encounter late snowfall or below-zero temperatures. crowns. The eggs are deposited individually into each cavity, and then sealed with fecal material. The oviposition site becomes M. cruciger is not common in its native range throughout Europe marked with a small dark green spot which appears blistered as it and western North Africa. It feeds on two varieties of Cynoglossum, hardens. By the end of May, this generation will have finished but is restricted to hound's-tongue (C. officinale) in Europe. In depositing eggs and most females die. However a few will move to Morocco and Algeria it feeds on C. cheirifolium. the soil to hibernate, reappearing intermittently over the remainder of the summer to briefly feed. The summer generation normally BRITISH COLUMBIA EXPERIENCES appears in mid summer, but small quantities of spring emerged Origin: weevils may persist throughout the summer. Immature adults are M. cruciger populations in BC originate from Hungary and Serbia. required to feed for about two weeks before mating and entering into their first oviposition period. The summer generation will start History: their first oviposition in September, laying up to 10 eggs before In 1997, six open field releases were made throughout the southern preparing to overwinter in the soil and plant litter. The spring adults interior, of which one was a research trial. Another population was that hibernated will emerge again in September, mix with the placed into rearing tents in Kamloops. British Columbia habitat is summer adults and mate and oviposit their third time. favourable for M. cruciger and agents were found the following year. In 2005, M. cruciger was designated to secondary status. Egg: Assisted redistribution is ongoing. Eggs are 0.9 x 0.6 mm. They require temperatures above 60C to develop. At 250C eggs hatch in seven days. Hatching occurs during Habitat: the oviposition period. M. cruciger releases have been made and found established and dispersed in the Bunchgrass, Interior cedar-hemlock, Interior Larva and pupa: Douglas-fir, Montane spruce and Ponderosa pine biogeoclimatic White larvae with brown heads, in a zones. It continues to increase and disperse throughout the typical weevil "C" shape, develop through hound's-tongue geographic range in BC. three instars. Bristles are the only differentiating feature that distinguishes Propagation results: the instars. Because the eggs are laid and In six years, from 1997 to 2002, 49,509 M. cruciger have been hatch throughout the oviposition period, released into BC habitat, of which 40,487 were reared at the larvae feeding occurs throughout the Ministry of Forests and Range Propagation Facility in Kamloops. year, except in August. The entire larval stage feeds on the roots. The first instar Field results: begins feeding from the upper crown downward. The second instar M. cruciger has proven to be a highly effective tool for controlling is usually found in the upper parts of tap roots. Mature larvae feed hound's-tongue. In a trial near Kamloops, the plants at a 2001 lower yet on the basal parts of the tap roots and secondary roots. release steadily decreased over four years. For example, on two This feeding pattern separates the instars, preventing competition permanent transects in 2003 there were 97 plants plants, in 2004 which can occur in high larvae densities. They often chew through there were 84 plants, in 2005 there were only 3 plants, and in 2006 root walls, exit and re-enter at another location. Larvae feeding and there were no plants. Because the plants are biennial, seedling mining tunnels become filled with light brown frass. Mogulones production may appear to increase every other year, however the cruciger larvae are not cannibalistic. Mature larvae leave the root to early emerging habit of M. cruciger adults feed heavily on all plants, pupate in the soil. Pupation occurs in a prepared silk oval cocoon, 7
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and therefore, completely destroy young rosettes and seedlings. In heavy populations plant roots are reduced to skeleton shells.
Collection for redistribution Adult field collections can be difficult. Adults drop easily from leaves, and camouflage on the soil.
NOTES M. cruciger can co-exist with Longitarsus quadriguttatus as they feed on different root parts, preferring different plant sizes and stages. Early spring emergence of adults rapidly decreases the plants' ability to set bolts. It was formerly known as Ceutorhynchus cruciger.
REFERENCES DeClerck, R. and P. Harris. 2006. Classical biological control of weeds established biocontrol agent Mogulones cruciger (Herbst). Root - feeding weevil. Gov. of Can., Agriculture and Agri-Food Canada. February 13, 2007
Jordon, T., M. Schwarzlander, I. Tosevski, and A. Freese. 1993. Ceutorhynchus cruciger Herbst (Coleoptera, Curculionidae): a candidate for the biological control of hound's-tongue (Cynoglossum officinale L., Boraginaceae) in Canada. C.A.B. Intern. Instit. Biol. Contr. 44 p. Mason P. G. and J. T. Huber (editors). 2002. Biological control programmes in Canada, 1981-2000. CAB International.
MFR STAFF OBSERVATIONS AND COMMENTS Province of British Columbia. 2003. Operational field guide to the propagation and establishment of the bioagent Mogulones cruciger (Hound's-tongue root weevil). Min. For., For. Practices Br., Range Sect., Nox. Weed Contr. Prog. 31 p.
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BIOLOGICAL CONTROL AGENT: PUCCINIA ACROPTILI SYD Collection for redistribution Collect infected plant material and scatter among plants at new Type of agent: Leaf and stem rust (fungus) locations. Successful spore transfer is best just prior to light rain or Status: Tertiary before dew accumulations.
Invasive Plant Species Attacked: NOTES Russian knapweed In Saskatchewan, on sites where P. acroptili co-exists with (Acroptilon repens) Subanguina picridis, galls produced by the nematode in the
previous year were heavily attacked with rust. The mixed DESCRIPTION AND BIOLOGY population appeared to promote extremely enlarged gall General development: development and the Russian knapweed plants became Rust coloured pustules form stunted. on plants every 12 - 16 days, covering stems and leaf REFERENCES surfaces. Harris, P. and R. L. Conner. 2005. Classical biological control of Detailed development: weeds established biocontrol agent Puccinia acroptili Syd. Leaf rust The rust fungus develops from its overwintering stage (teliospores) disease. Gov. of Can., Agriculture and Agri-Food Canada. Feb 15, and germinates into spores that require cross pollination 2007. (basidiospores). Spores develop club-shaped structures in summer,
where the spores (usually three) develop at the tips of diminutive stalks. The pollination process is usually is done by flies or other MFR STAFF OBSERVATIONS AND COMMENTS insects as they move through the plant community. After initial Mortensen, K. and M. M. Molloy. 1989. Fungi detected on cross pollination they develop into single celled yellow-brown Acroptilon repens (Russian knapweed) during surveys from 1981 to spores (urediospores), which are self-producing. The advantage of 1988. Can. Plant Dis. Survery. Vol. 69: 2, 143 - 145. this method of development is rapid spread with multiple, reproductive generations each season. When days shorten in the Powell, G. W., A. Sturko, B. Wikeem and P. Harris. 1994. Field guide autumn, the rust develops the overwintering spores (teliospores). P. to the biological control of weeds in British Columbia. B.C. Min. For. acroptili occurs on upper and lower leaf surfaces. Spores are wind Res. Prog. dispersed.
Overwintering stage: Thick-walled spores (teliospores) that are medium chestnut-brown coloured, develop on dead leaves in the fall and remain so until spring germination.
LOCATION AND EFFECTIVENESS OF ATTACK Heavy attack is required to kill leaves. In its native habitat Puccinia acroptili kills plants.
PREDICTED AND NATIVE HABITAT P. acroptili occurs widespread within Russian knapweed habitat. Large, dense stands appear to be more affected by the rust than small patches or isolated individual plants. In North America its distribution occurs from Mexico into British Columbia, and east to Saskatchewan. Establishment in Saskatchewan and British Columbia suggests that it also occurs in Alberta.
P. acroptili originates in south-central Asia.
BRITISH COLUMBIA EXPERIENCES Origin: It is not clear how P. acroptili established itself in BC.
History: It is unknown when P. acroptili first established in BC. It was redistributed in 1985 and 1986 into three locations, Cawston; Walhachin; and, Okanagan Falls. All sites established and it is self- dispersing throughout the southern interior of BC.
Habitat: P. acrolptili has been found established been found at all treatment sites. Dispersal appears quite widespread in the Bunchgrass and Ponderosa pine biogoclimatic zones.
Field results: P. acroptili occurs in Russian knapweed stands throughout the province at varying levels of effectiveness. At all sites, some plants appear resistant with no negative impact while others next to them that have heavy rust are collapsing.
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BIOLOGICAL CONTROL AGENT: PUCCINIA CHONDRILLINA BUBAK & Field site symptoms include rapid kill to seedlings and weak, thin- rooted rosettes. On mature plants, leaves die back and stems SYD. become deformed, producing fewer branches, fewer flowers, and Type of agent: Leaf and stem rust (fungus) less viable seed. Status: Tertiary Well established plants rarely show reduced vigour, therefore heavy Invasive Plant Species Attacked: attack over multiple years may be required for control. In some Rush skeletonweed stands weed density is reduced 56 - 87% in five years. Dispersal has (Chondrilla juncea) been reported as 3 km in one year, 5 km in two years and 10 km in three years. DESCRIPTION AND BIOLOGY General development: PREDICTED AND NATIVE HABITAT Sexually reproducing P. chondrillina is capable of inhabiting all areas where rush fungus appears in clusters skeletonweed is established. The most effective sites are warm and on rosette leaves that give rise to airborne spores that develop into moist which allow for rapid reproduction with multiple generations brown pustules. Attacking pustules appear on upper and lower leaf per year. Overnight dew production increases spread and surfaces of seedlings and spring or fall rosettes. Wind and rain effectiveness. Some plants show whole or part immunity to the rust dispersal contributes to rapid reproduction; completing every 12 - fungus strains in North America. In the Mediterranean, Australia and 16 days. California it is the most effective controlling agent for rush Detailed development: skeletonweed. Overwintering spores (teliospores) germinate in the spring producing one or two club-shaped structures (basidium) where P. chondrillina is widespread in Eurasia occurring on rush spores develop at the tips of diminutive stalks. The spores develop skeletonweed in, Iran, Turkey, Greece, Yugoslavia, Italy, France, into the aecial stage which requires sexual reproduction involving Spain, and Portugal. In south Russia, is also occurs on a second pollination. After pollination, they germinate at 18 - 200C to become Chondrilla species. self-reproducing (urediospores) and within 3 - 16 hours, penetrate the leaf tissue. The self fertile spores have an advantage of rapid BRITISH COLUMBIA EXPERIENCES 0 spread, capable of multiple generations each season. At 20 - 30 C, Origin: they reproduce every 7 - 10 days, depending on weather conditions. The P. chondrillina variety in BC originated in Europe and it is By mid summer, usually when flowers are beginning to form, believed have entered into BC from the United States. overwintering spores (teliospores and urediospores) are produced, developing mainly near the base of the flower shoots, appearing History: elongated, black and leather-like. Spores (urediospores) are light- P. chondrillina was first found in 1992 in the North Okanagan. weight and powdery, which easily disperse in wind and rain. Pustules are common by late summer or early fall. In mild, moist Habitat: winter climates, steady spread can occur all winter, followed by P. chondrillina is established in the Interior Douglas-fir and Interior rapid spread in the spring, then slowing during the dry summer cedar-hemlock zones. Low level attack in the Vernon area indicates months. Winter kill or slow spring emergence of rosette basal insufficient moisture. A higher level of attack can be achieved with foliage stalls early spring spore development. Dry summer climates increased moisture. reduce the generations produced each year. Field results: There are several strains of this rust and some plants may be P. chondrillina generally occurs in rush skeletonweed stands so no immune to it. In these instances the plants will have the rust present redistributions have been made. In the north Okanagan sites, winter and as it tries to infect the plant, immune plants will exhibit small can kill rosettes with overwintering spores which reduces the brown dimples as they restrict further development. When bioagent's impact. It is commonly sharing the same host plants as attacking somewhat resistant plants, the pustules develop a yellow the bioagent Eriophyes chondrillae. halo with restricted spore production. On plants with no immunity, large brown pustules develop over the entire plant. In cold climates, Collection for redistribution the sexual reproductive generation may reappear with gene Infected plants can be clipped and distributed among plants at new reconfigurations as it tries to develop strains that can break through locations. Mixing the self-producing urediospores with talc or oil and the immune plants protective mechanisms, resulting in numerous applying by dusting or spraying can be done. Moisture levels should Puccinia chondrillina strains. be increased for at least three hours by lightly misting the plants or covering them with plastic bags. Overwintering stage: In cold climates the rust develops thick walled spores (teliospores), Natural distribution of P. chondrillina is common and usually common to areas north of southern Idaho. The following spring, requires no further assistance. teliospores must germinate to initiate further development. In mild climates (Washington State and south) it overwinters in dormant NOTES forms of self producing spores or as sexual reproductive spores. The Canadian strain of P. chondrillina is believed to the be same as that found in Washington State (identified as PC-16) LOCATION AND EFFECTIVENESS OF ATTACK but further investigation is required to confirm this theory. In European experimental plots: Infected mature plants died at a rate of 50 - 70%; REFERENCES Seedling death occurred at 90-100%; Delfosse, E. S., A. Hasan, J. M. Cullen and A. J. Wapshere. 1985. Mature rosette mortality increased 2.1 - 4.6 times; Beneficial use of an exotic phytopathogen Puccinia chondrillina , as a Infected plants produced fewer flower shoots and basal biological control agent for skeletonweed, Chondrilla juncea, in rosettes; and Australia. In: Gibbs, A. J., 1985. Pests and Parasites as Migrants: an Root regeneration was reduced to 13.3%. Australian Perspective, Carbarra, Australia Academy of Sciences: 171 -177.
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Harris, P. 2005. Classical biological control of weeds established biocontrol agent Puccinia acroptili Syd. Leaf rust disease. Gov. of Can., Agriculture and Agri-Food Canada. Feb 15, 2007.
MFR STAFF OBSERVATIONS AND COMMENTS Powell, G. W., A. Sturko, B. Wikeem and P. Harris. 1994. Field guide to the biological control of weeds in British Columbia. B.C. Min. For. Res. Prog.
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BIOLOGICAL CONTROL AGENT: PUCCINIA JACEAE OTTH. Habitat: P. jaceae is recorded established in the Bunchgrass and Ponderosa Type of agent: Leaf and stem rust (fungus) pine biogeoclimatic zones. It is believed to be more widespread than Status: Tertiary is recorded. The dry interior regions of southern BC may restrict continual reproduction. Invasive Plant Species Attacked: Diffuse knapweed Field results (Centaurea diffusa), When P. jaceae was first located near Oliver, the plants had 15 - Spotted knapweed 20% of stem and leaf area covered with rust pustules. From the (C. beibersteinii) original 10 km2 site, it dispersed to 1,400 km2 in seven years. Spotted knapweed acceptance is variable, the variety found in DESCRIPTION AND BIOLOGY Oliver showed 26% susceptible and 38% immune. General development: Twelve to 16 days Collection for redistribution after inoculation, Clipped stems with infected plant material can be collected and rust-coloured scattered into new locations. Because of its wide distribution in BC, pustules range from further assistance is usually not required. 0.4 - 1.3 mm in diameter, with a yellow halo. The fungus attacks stems and leaves which gradually turn brown. Recurring generations NOTES 0 are produced every two weeks at 15 - 20 C. The specific variety P. jaceae var diffusae is produced, but does Detailed development: not develop on spotted knapweed. Pucccinia jaceae has five stages of development on two host plant varieties in Canada. Overwintering spores (teliospores) develop into REFERENCES wind borne spores (basidiospores) in the spring. Germination often Harris, P. 2005. Classical biological control of weeds established occurs on alternate hosts within the plant community which results biocontrol agent Puccinia jaceae Otth. var diffusae. Leaf and stem in sexual reproducing pustules. The pustules produce a sweet necter rust disease. Gov. of Can., Agriculture and Agri-Food Canada. that attracts insects. The pollination process is usually is done by February 15, 2007. flies or other insects as they move through the plant community.
After pollination, the spores then develop into sexual reproductive spores (aeciospores). The aeciospores germinate and in turn create MFR STAFF OBSERVATIONS AND COMMENTS self-producing spores (urediospores) which require a moisture Mortensen, K. P. Harris, and R. M. D. Makowski. 1989. First period of 18 - 20 hours for germination. The advantage of occurance of Puccinia jaceae var. diffusae in North America on urediospores is their ability to rapidly duplicate. In this stage they diffuse knapweed (Centaurea diffusa). Can. Journ. Plant Path. 11: are capable of dispersing long distances. As the day length shortens, 322-324. or with the onset of drought, they begin to develop the overwintering spores (teliospores). Powell, G. W., A. Sturko, B. Wikeem and P. Harris. 1994. Field guide to the biological control of weeds in British Columbia. B.C. Min. For. Overwintering stage: Res. Prog. In the dryer climates, P. jaceae may overwinter as mycelium on knapweed rosettes or as sexual reproductive spores on alternate plants. In some climates it overwinters as thick walled spores (teliospores) on plant debris.
LOCATION AND EFFECTIVENESS OF ATTACK P. jaceae can be observed from summer through fall on leaves and stems. Rust pustule coverage on leaves and stems can be up to 20%. Moist conditions increase reproduction, affecting more plants and larger areas. Inoculated four week old diffuse knapweed plants have 55% less root and 33% less leaf biomass than plants not affected. It is only effective when attacking seedling form. Heavy infection on five week old plants reduces the leaf life span by 66 - 76%.
PREDICTED AND NATIVE HABITAT P. jaceae is capable of inhabiting all diffuse and spotted knapweed habitats. Increased moist habitat, more common with spotted knapweed, can encourage rust reproduction. Dry climates inhibit reproduction. P. jaceae is native to western Europe found between latitudes 440N to 620N, and to the Caspian Sea within latitudes 350N to 550N.
BRITISH COLUMBIA EXPERIENCES Origin: P. jaceae originates in western Europe and the first recorded North American site occurred in BC.
History: The first known sighting of P. jaceae in North America was on diffuse knapweed found in 1988 in Oliver, BC. The rust has freely dispersed itself with no assisted redistribution efforts.
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BIOLOGICAL CONTROL AGENT: RHINOCYLLUS CONICUS FROEL the preferred area where a minor callus develops or in stems where no callus forms. The third instars prepare to pupate and the fourth Type of agent: Seed feeding beetle (weevil) instars construct a hard black chamber made from feces and Status: Primary on Marsh plume thistle chewed plant material. Multiple chambers fuse together and Status: Secondary on Bull thistle, Canada become a large mass. Larvae complete development in 39 to 46 thistle, Plumeless thistle and Scotch days after hatching. Pupae are creamy white during the pupation thistle period which lasts 8 - 14 days. New immature adults linger in the Status: Tertiary on Nodding thistle chamber for several weeks before chewing an exit hole to escape. Up to 65 larvae can develop in nodding thistle heads that have a 30 Invasive Plant Species Attacked: mm radius. Nodding thistle (Carduus nutans), Overwintering stage: Plumeless thistle Rhinocyllus conicus overwinters as adults, where they seek refuge in (C. acanthoides), sheltered locations. They will overwinter in the plant duff or soil, in Marsh plume thistle tree bark crevices, or in woody debris. (Cirsium palustre), Canada thistle LOCATION AND EFFECTIVENESS OF ATTACK (C. arvense), R. conicus is an important agent for control of nodding and Bull thistle plumeless thistles which reproduce strictly by seed. Each larva (C. vulgare), contributes by reducing 16 seeds in the head it occupies and Scotch thistle suppresses the development of seed in other heads. Adults feed on (Onopordum acanthium) foliage and leave signature rounded feed holes over the entire leaf surface. DESCRIPTION AND BIOLOGY Adult: PREDICTED AND NATIVE HABITAT Adults are 3 - 7 mm long, oblong, black weevils. They have patches R. conicus establishes on open sites wherever the host thistles grow of brown and light grey hairs distributed over their backs. Their in well drained soils. It favours dense stands over widely spaced or rostrum (nose) is short making it distinctly different from Larinus scattered patches. Dry, hot sites with rapid temperature increases in planus which occurs on many of the same plants. The summer early summer prevent optimal larval development and seed generation adults emerging in August have the same hair tufts as destruction and therefore, locations with moderate temperatures the spring generation, but the hair appears patchy yellow at first, are more effective. Of all the host plants, its greatest preference is which gives them the appearance of being covered with pollen. In for nodding thistle. early May, adults emerge from overwintering locations and feed on foliage. Adults disperse by flying, with the main dispersal period R. conicus - native origin occurs in North Africa, South and Central occurring in the spring when they seek out host plants for feeding. Europe, the Caucasus Mountains, Kazakhstan and Asia Minor. Mating and Egg-laying begins in early summer. Eggs are laid during the entire single flower phase of nodding thistle, but only during BRITISH COLUMBIA EXPERIENCES three waves of the plumeless thistle bloom phase. Each female lays Origin: an average of 200 eggs onto floral bud bracts. Each egg is deposited The R. conicus populations released in BC originate from France. individually and covered with chewed plant material, which forms a protective cap. Over time, the cap turns light brown and is highly History: visible. Ants are attracted to the cap, which they care for. Early R. conicus was first introduced to nodding thistle in BC in 1979 west oviposited eggs may be accidentally laid into enclosed terminal of Williams Lake. Field collections and releases are still ongoing, but leaves, in these instances, the resulting larvae will not survive. the weevils are more often released onto plants other than nodding Multiple eggs can develop successfully within a single head. thistle. In 1997 and 1998 weevils were collected from near Princeton off nodding thistle and released onto marsh plume thistle The summer generation adults remain in their cell chambers for in the Robson Valley. In 1999 an adult was found inside a seedhead, several weeks, changing from cream or reddish tan to almost black. but subsequent monitoring confirmed no further evidence. If they are in the seedhead portion of the plant they chew through To confirm that R. conicus would transfer to marsh thistle, MFR the upper part of the flower bud. Those in the stem chew through commissioned Agriculture and Agri-Food Canada (AAFC) in the stem wall near the base of the bud and exit through the Lethbridge to raise R. conicus weevils on marsh thistle in their opening. They remain on the plants for a short time before laboratory. The weevils successfully completed their life cycles. In hibernating, however those that emerge during >16 hour days will 2004 and subsequent years, a cold hardy strain of R. conicus go on to produce a second generation. obtained from Alberta has been released and survived in the Robson Valley. Some of these were released into propagation tents to Egg: contain the agent and prevent early dispersal. In 2007, all the tents Eggs incubate for 6 - 9 days. were removed after it was determined the tented environment reduced the plants' vigour. Larva and pupa: Larvae remain creamy Habitat: " " white, C shaped, and with Establishment and dispersal have been found widespread on pale yellow-brown heads nodding, plumeless and Canada thistles growing in the Bunchgrass, during all instar stages. Coastal western hemlock, Engelmann spruce-subalpine fir, Interior New larvae enter the bud cedar-hemlock, Interior Douglas-fir and Ponderosa pine through the bracts and biogeoclimatic zones. The weevil collections taken from nodding begin to feed at the thistle and put on marsh plume thistle in the Robson Valley has not preferred area just below established well in the Sub-boreal spruce zone. the seeds. This is where an important and nutritious Field results: food source develops within 2 - 3 days with the formation of a callus growth. Some larvae will mine the less nutritious locations below 35 | P a g e
Marsh Thistle: R. conicus collected from nodding thistle and released on marsh plume thistle in 1997 and 1998 in the Robson Valley establishment appear to be unsuccessful at this time. Another attempt was made in 1999 and the following year a live weevil was teased out of a seedhead. However no evidence of long term establishment has been found at the site thereafter, leading to the suspicion that the weevil failed to adapt to climatic conditions of the Robson Valley. The cold hardy strain from Alberta appears to be better suited to these sites. Scotch thistle: The 1998 release on Scotch thistle was monitored in the past and an unknown larva was found, however it was not confirmed to be R. conicus and the site status remains unknown at this time. The weevils appear to move freely onto the less preferred thistle species when nodding thistle becomes displaced. The weevils co- exist with Larinus planus and Urophora cardui in Canada thistle stands. They also co-exist in nodding thistle and plumeless thistle stands with L. planus and Trichosirocalus horridus. R. conicus larvae have been found in the same bull thistle seedheads with U. stylata larvae.
Collection for redistribution Adults can be aspirated or swept off plants during bright sunny and warm days in August. However thistle plants do not fare well from sweeping and make a mess of the nets. Adults can also be extracted from seedheads in August or allowed to exit on their own within a cage and released into new sites.
R. conicus is not available for general distribution on marsh plume thistle at this time.
NOTES Native parasites kill 3% of larvae in nodding heads, 16% in plumeless heads, and 19% in nodding stems. The herbicide 2, 4-D can be sprayed on bolting and bolted plants without harming the developing larvae. R. conicus strains collected in Europe off Italian thistle will use Scotch thistle (Onoporum acanthium), slender flower thistle (Carduus tenuiflorus), and milk thistle (Silybum marianum) as host plants in North America.
REFERENCES Harris, P. 2005. Classical biological control of weeds established biocontrol agent Rhinocyllus conicus Froel. Seed-head weevil. Gov. of Can., Agriculture and Agri-Food Canada. February 15, 2007.
MFR STAFF OBSERVATIONS AND COMMENTS Powell, G. W., A. Sturko, B. Wikeem and P. Harris. 1994. Field guide to the biological control of weeds in British Columbia. B.C. Min. For. Res. Prog.
Rees, N. E., Quimbly, Jr., P. C., G. L. Piper, E. M. Coombs, C. E. Turner, N. R. Spencer, L. V. Knutson (editors). 1996. Biological control of weeds in the west.
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BIOLOGICAL CONTROL AGENT: RHINUSA ANTIRRHINI (PAYKULL) Overwintering stage: Type of Agent: Seed head feeding beetle (weevil) Adults overwinter within soil duff. Sometimes they will also spend Status: Secondary winters above ground inside the dried seed capsules.
Invasive Plant Species Attacked: LOCATION AND EFFECTIVENESS OF ATTACK Dalmatian toadflax Larvae feed on seeds, completely destroying all the seeds in the (Linaria dalmatica), capsule that they occupy. Adults feed on foliage which can add to Narrow-leaved plant stress and reduces vigour. Adult pollen and flower feeding also Dalmatian toadflax contribute to decreased seed production. On yellow toadflax R. (L. genistifolia spp . antirrhini can reduce seed production by 20-25%. dalmatica),
Yellow toadflax (L. vulgaris) PREDICTED AND NATIVE HABITAT There are two strains of R. antirrhini; each showing a preference for Operational Field Guide: either Dalmatian or yellow toadflax varieties. The strain found on Rhinusa antirrhini - yellow toadflax is believed to have been unintentionally introduced. Operational Field Guide, Ministry of Forests and Range The first North American published record indicates it was present in Massachusetts in 1909, (earliest Canadian specimens were found in 1917 in Quebec). DESCRIPTION AND BIOLOGY Dalmatian toadflax and narrow-leaved Dalmatian toadflax strain: Note: Unless noted otherwise, the information provided represents both R. antirrhini habitat is limited to where summers are warm to hot strains of Rhinusa antirrhini. and winters are mild. Adequate snow cover adds protection where Adult: winters may be harsh. It prefers open sunny locations and is Adults are oval, black bodied and 5 mm long when on Dalmatian common on south and west aspects. Dense stands growing in well toadflax and 3 mm long when on narrow-leaved Dalmatian toadflax. drained soils are ideal. The rostrum (nose) is curved and pointed and from the side it Yellow toadflax strain: appears tapered. All but the tip of the rostrum is covered with Commonly found and establishes easily on host plants in a variety of pubescence. Their bodies have fine yellow-brown hairs arranged in climates. rows. Adults appear in May when plants are 20 - 30 cm tall. They
feed first on tender new growth which initiates branching lateral The native distribution of R. antirrhini is from north Africa (Algeria) growth, then they move to flowers to feed on pollen and young to the northern limits of yellow toadflax, into the Baltic countries seeds. Several adults can be present in a single bloom. R. antirrhini and is frequently found in the cool moist habitats of Europe. normally lay eggs from June through August, often having to delay
oviposition until Brachypterolus pulicarius damage has subsided. When the flowers have enlarged to just about as large as they will BRITISH COLUMBIA EXPERIENCES become, the females will prepare oviposition sites by chewing into Origin: the green pods. A single egg is inserted into each cavity, but up to The R. antirrhini populations released in BC orginate from eight may be laid into each pod, which are covered with a yellow Yugoslavica. The adventives strain found on yellow and narrow- secretion. Within one week, a wart-like or nipple-like protrusion can leaved Dalmatian toadflax found throughout BC is believed to have be seen just above the oviposition point. At the same time, the egg originated in Eurasia. is lifted into the protrusion, which prevents it from becoming damaged while also placing the egg deep into the developing seeds. History: The seeds nearest the egg swell abnormally, 8 - 10 times larger, and R. antirrhini was first introduced into propagation tents in 1995 in become pale coloured. Females lay an average 54 eggs, but they Kamloops. The first field release in BC was made in 1996 near range from 10 to 132 eggs and will continue to lay as long as Kamloops onto Dalmatian toadflax. Early monitoring indicated no suitable flowers are available, even though eggs or new larvae may establishment at the field site and soon after access to the site was not survive the winter. New adults from the spring mating will closed preventing further follow up. In 2008 R. antirrhini was emerge in August and September but not mate or oviposit, instead designated secondary status. Assisted redistribution is ongoing. they overwinter. Adults that emerged in spring and early summer will live until September. The adventive strain of R. antirrhni commonly found in BC on yellow toadflax was first located in the 1950s. It has been found widely Egg: dispersed in BC and no assisted dispersal has been done. The eggs are oval but flattened, and 0.49 x 0.27 mmin length. Incubation takes 12 - 17 days. Habitat: Dalmatian toadflax strain Larva and pupa: R. antirrhini establishes easily in the Thompson - Okanagan, and Full grown larvae are 0.54 mm long Kootenay climates. Releases were made in the Bunchgrass, Interior and have a clear dark brown head. Douglas-fir, Montane spruce, Ponderosa Pine and Sub-boreal spruce Typical to weevils, their distinct "C" biogeoclimatic zones. Establishment and dispersal have been found shape can be easily identified in pods in all except the Montane when broke open. The first larvae spruce and Sub-boreal instars feed on the pale enlarged spruce zones. seeds. Several larvae can occupy a single seed pod chamber. The final Yellow toadflax strain instar may feed on regular developing The adventive strain of R. seeds. Pupation takes 10 - 15 days, antirrhini is commonly found occurring within the seedpod where on yellow toadflax mature larvae build an oval cell. R. throughout the southern antirrhini can be identified by two interior. Dispersal sightings occur in the Interior Douglas-fir, pointed horns at the top of their thorax. New adults emerge Ponderosa pine and Sub-boreal spruce biogeoclimatic zones. through the upper opening of dried seed capsules.
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Propagation results: Rees, N. E., Quimbly, Jr., P. C., G. L. Piper, E. M. Coombs, C. E. In 1999 the R. antirrhini the rearing tents began to produce collectable Turner, N. R. Spencer, L. V. Knutson (editors). 1996. Biological populations. From 1999 to 2007, 15,937 adult weevils were collected from the control of weeds in the west. tents for redistribution. In 2007, rearing tents were dismantled and the agent was reassigned to secondary status. Smith, J. Morris. 1959. Notes on insects, especially Gymnaetron spp. (Coleoptera: Curculionidae), associated with toadflax, Linaria Field results: vulgaris Mill. (Scrophulariaceae), in North America. Can. Entomol. Dalmatian toadflax strain Vol. XCI, No. 2: 116-121. In the field, the overwintered adults emerge and can be observed during the same time Mecinus janthinus is collected (May and June). The generation resulting from the spring adults begin to appear in early August and last at least one month before they prepare to overwinter. Initially the 1996 field release did not show establishment and soon after access to the site was restricted and no further monitoring could be done. In 2005, weevils were found and following positive identification of R. antirrhini, dispersal monitoring was initiated around this early release. Results showed that R. antirrhini had established near Kamloops and was subsequently found great distances from the original release point. As well, the weevil has dispersed significantly in the North Thompson. It is probable it is widely spread in other parts of the southern interior, including Princeton, the Okanagan, and the Kootenays. By 2007, 98% of all treatment sites have established. R. antirrhini appear to be easier to tease from flowers than R. neta.
M. janthinus attack creates delayed flowering and may cause R. antirrhini to disperse and/or oviposit later in the season. When competition is heavy among the bioagents, the few flowers blooming in late summer invites adults to congregate in large numbers. On a single plant, R. antirrhini, R. neta, and M. janthinus were found in August. In the rearing tents, adults have been observed mating and ovipositing well into late August. It is not known what success the late oviposited eggs and hatching larvae have for overwintering. Seed pods attacked by Rhinusa spp. can be detected by a pale tan coloured, grainy textured substance that can be seen from the open end of the pod. When these are broke open, one or more larvae, pupae or developed adults can be found unless the weevils have already emerged. New adults ready to emerge can often be seen with their heads or posteriors visible through the opening as they will have moved the grainy, tan particles aside for easy emergence. As well, adults may chew a hole through the pod wall to emerge as an alternative to the natural opening at the top.
Yellow toadflax strain Larvae were found in seedpods in early May at cool, semi-shaded locations in the Interior Douglas-fir zone. Adults were found in the southern interior during yellow toadflax bloom from late May through August.
Collection for redistribution Plants can be swept for adults from June through September. Aspirating is most effective and less damaging to the plants.
NOTES When existing on the same plants as R. neta in their natural European habitat, R. antirrhini is 50% smaller. When combined with B. pulicarius , seed reduction can be 85 - 95%. Formerly known as Gymnetron antirrhini and Gymnaetron antirrhini.
REFERENCES Harris, P. and A. Gassmann. 2003. Classical biological control of weeds. Gov. of Can., Agriculture and Agri-Food Canada. May 20, 2003
MFR STAFF OBSERVATIONS AND COMMENTS Powell, G. W., A. Sturko, B. Wikeem and P. Harris. 1994. Field guide to the biological control of weeds in British Columbia. B.C. Min. For. Res. Prog.
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BIOLOGICAL CONTROL AGENT: RHINUSA NETA GERMAR Its native distribution is south and central Europe, through the Type of Agent: Seed head feeding beetle (weevil) Mediterranean to Iran but is absent in Denmark and Sweden. It is Status: Tertiary most common in locations with hot dry summers.
Invasive Plant Species Attacked: BRITISH COLUMBIA EXPERIENCES Dalmatian toadflax (Linaria dalmatica), Origin: Yellow toadflax (L. vulgaris), The original population source of the R. neta in BC is unknown. Narrow-leaved Dalmatian toadflax (L. gentistifolia spp. dalmatica)
History: DESCRIPTION AND BIOLOGY R. neta is adventive to BC. The weevil found its way here and has Adult: freely dispersed adding to the control of toadflax. Because it is Rhinusa neta colouring is quite variable, from ash-grey to olive frequently seen in the field, few collections and releases have been brown. Their oval, convex bodies are more rounded than other made. Rhinusa, and are usually significantly larger. Their rostrums (noses) are rigid, straight and have a blunt tip. Their bodies are covered with Habitat: fine yellow-brown hairs arranged in rows. Adults appear in May R. neta has been found throughout the southern interior in the when plants are 20 - 30 cm tall. At first, they feed on tender new Bunchgrass, Interior Douglas-fir, Montane spruce, and Ponderosa growth which initiates branching lateral growth and they later move pine biogeoclimatic zones. into flowers to feed on pollen and young seeds. Several adults can be present in a single blossom. Females normally lay eggs from June Field results: through August and sometimes need to delay oviposition until It establishes on Dalmatian and yellow toadflax varieties along side Brachypterolus pulicarius feeding damage has subsided. When Mecinus janthinus, R. antirrhini, B. pulicarius and R. linariae. R. neta flowers are near peak bloom, females chew round holes into the are harder to be teased or coax out of flowers than R. antirrhini. green seed capsules and singly deposit up to eight eggs, covering Initially thought to have a preference for yellow, it is found equally them with a yellow secretion. The base of the egg, pointed towards in BC on Dalmatian and yellow toadflaxes. the oviposition hole, causes the site to become black and forms a barrier for the other end of the egg which is inflated. The barrier Collection for redistribution pushes the egg deep into the developing seeds. Seeds nearest the Plants can be swept for adults from June through September. egg expand 8 - 10 times their normal size, becoming pale coloured. Aspirating is most effective and less damaging to the plants. R. neta Each female averages 45 eggs, but can range from 21 to 66. They is often found in the field at the same time as other Rhinusa spp., will continue to lay eggs as long as suitable flowers are available, but it is not acceptable to redistribute the species in mixed even though eggs or larvae may not survive the winter. New adults populations. More than one species can be collected at the same resulting from spring mating emerge in August and September but time, however sorting and recording each is necessary. do not mate or oviposit, instead they overwinter. Adults that emerged in the spring or early summer live until September. NOTES
R. neta was formerly known as Gymnaetron netum and Egg: Gymnetron netum and is currently also known as R. netum. The eggs are oval and flattened, 1.23 x 0.67 mm when first laid, When existing on the same plants in their natural European swelling over two or three days to 1.43 x 0.83 mm. Incubation takes habitat with R. antirrhini, R. neta is 50% larger. 12 days.
Larva and pupa: REFERENCES Full grown larvae are 0.63 mm long and have a vague light brown Harris, P. and A. Gassmann. 2003. Classical biological control of pattern. Typical to weevils, their distinct "C" shape can be easily weeds. Gov. of Can., Agriculture and Agri-Food Canada. May 20, identified in pods when opened. There are three larvae instars. The 2003. first instars feed on the enlarged pale seeds. Several larvae can occupy a single seed pod chamber. The final instar may feed on Gassmann, A. and C. Paetel. 1998. Gymnetron netum (Col.; regular developing seeds. Pupation occurs within the seedpod Curculionidae) a potential agent for biological control of toadflax in where mature larvae build an oval cell. They can be identified by North America. CABI Bioscience, Div. CAB Internat., Switzerland. two blunt horns at the top of their thorax. Five weeks after hatching Summary Report 1996-1998. 43 p. from eggs, new adults emerge through the upper opening of dried seed capsules. MFR STAFF OBSERVATIONS AND COMMENTS Smith, J. M. 1959. Notes on insects, especially Gymnaetron spp. Overwintering stage: (Coleoptera: Curculionidae), associated with toadflax, Linaria Adults overwinter in plant and soil duff. Sometimes they will also vulgaris Mill. (Scrophulariaceae), in North America. Can. Entomol. spend winters above ground inside the dried seed capsules. Vol. XCI, No. 2: 116-121.
LOCATION AND EFFECTIVENESS OF ATTACK Larvae feed on seed, completely destroying all the seeds in the capsule that they occupy. Adults feed on foliage which may add to plant stress and reduce vigour. Adult pollen and flower feeding also contribute to a decrease in seed production.
PREDICTED AND NATIVE HABITAT R. neta is native to Europe and was unintentionally brought to North America. The first North American published record indicates it was present in the eastern seaboard states in 1937, and the Pacific Northwest, including BC, in 1954. In Canada, it is common on invasive toadflax varieties in varying habitats and climates, including the prairies. 39 | P a g e
BIOLOGICAL CONTROL AGENT: SCLEROTINIA SCLEROTIORUM (LIB.) Type of agent: Root, leaf and stem fungus REFERENCES Ford, E. J. No date. Sclerotinia as a mycoherbicide. No journal. Pp. Status: Tertiary 182-189.
Invasive Plant Species Attacked: Harris, P. 2005. Classical biological control of weeds established Spotted knapweed biocontrol agent Cyphocleonus achates (Fahr.). Root-core feeding (Centaurea biebersteinii), weevil. Gov. of Can., Agriculture and Agri-Food Canada. Feburary 7, Diffuse knapweed 2007. (C. diffusa)
Harris, P., J. Myers, K. Mortensen, D. Berube. No date. Biological DESCRIPTION AND BIOLOGY control of knapweed. No Journal. 9 p. Reproductive stage: Sclerotinia sclerotiorum are Huang, H. C. 1992. Biocontrol: an old idea for modern agriculture. single cell structures which Weekly Letter. Agric. Canada, Res. Br., Res. Station Lethbridge. W. L. reproduce asexually. Fruiting spores develop in open cup and saucer No. 3032. 1 p. like structures. Water and moist soils encourage spread and lengthen its infective period. MFR STAFF OBSERVATIONS AND COMMENTS
Story, J. M., W. R. Good and L. J. White. 1993. Propagation of Agapeta zoegana Overwintering stage: L. (Lepidoptera: Cochylidae) for biological control of spotted knapweed: It survives through the winter in an overwintering structure called procedures and cost. Biol. Contr. 4: 145-148. sclerotia.
LOCATION AND EFFECTIVENESS OF ATTACK S. sclerotiorum causes rapid and total plant collapse. In studies it was identified to cause death to 10% of flowering knapweed plants. Plants attacked exhibit wilt as the fungus infects the leaves, stems and roots. It effectively kills juvenile spotted knapweed plants and decreases stand density. Seedlings infected with the rust are killed within two weeks. S. sclerotiorum is most effective in dense plant stands. It reduces spotted knapweed productivity by 75%.
PREDICTED AND NATIVE HABITAT S. sclerotiorum occurs on a wide variety of habitats, thriving and spreading in moist or irrigated conditions. It has a wide host range, affecting 383 plant species, but does not affect trees or grasses. It can establish in dry habitat, but it is unable to produce fruiting spores in dry conditions.
BRITISH COLUMBIA EXPERIENCES Origin: S. sclerotiorum is native to BC.
History: S. sclerotiorum is a naturally occurring soil borne fungus found in BC.
Habitat: S. sclerotiorum has been found in the Bunchgrass, Interior Douglas- fir and Ponderosa pine biogeoclimatic zones. It can be found through out the knapweed range at low elevations.
Field results: Study exclosures were maintained in Westwold and Pritchard to determine the effectiveness of S. sclerotiorum as an alternative to controlling knapweed with picloram on rangeland. Redistribution is not recommended as it will also affect favourable crops. In the biocontrol propagation plots at Kamloops, S. sclerotiorum was a pest that attacked knapweed host plants. Once the plants were inoculated they did not recover and eventually died.
Collection for redistribution Not applicable. Redistribution is not recommended.
NOTES S. sclerotiorum infection had increased production costs of preferred biological control agents. It also interferes with vegetable and seed oil crops, notably canola, safflower and sunflower. Cyphocleonus achates, a root feeding agent, may assist with inoculation during oviposition.
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BIOLOGICAL CONTROL AGENT: SPHENOPTERA JUGOSLAVICA do so in reduced quantities (41 - 57% less). Plants are usually attacked over more than one year, adding significant negative OBENB. impact. Type of agent: Root feeding beetle Status: Tertiary PREDICTED AND NATIVE HABITAT Sphenoptera jugoslavica thrives in arid environments that have a Invasive Plant Species Attacked: period of drought in summer. It prefers well-drained coarse soils on Diffuse knapweed south aspects. Exposed soil between plants will increase the soil (Centaurea diffusa), temperature which further enhances a preferred environment. It Spotted knapweed (C. exists in Bunchgrass and Ponderosa pine habitat. Locations with beibersteinii) aspen, Douglas-fir or lodgepole pine are probably too moist. It has a preference for diffuse knapweed over spotted knapweed. DESCRIPTION AND BIOLOGY Adult: S. jugoslavica is native to only a few European countries including, Stout beetles have a hard Romania, Bulgaria, Greece, European Turkey, and the former outer shell and are 7 - 10 mm long. The front of their head is flat and Yugoslavia. their posterior end is tapered into an oval shape. They are dark metallic copper, bronze or black. When startled or fearful they will BRITISH COLUMBIA EXPERIENCES play dead. Males emerge one week before females in July, just as Origin: the plants are forming flowers. Within a few days mating begins. The S. jugoslavica populations released in BC originate from Females must feed to ensure egg maturation, consuming 0.25 Macedonia. cm² of foliage. Five to 12 days after mating, oviposition begins and continues over their four week life span. Females lay an average History: of 50 eggs into rosette leaf axils. Their U-shaped rear abdomen The first field two releases of S. jugoslavica occurred in 1976 in the requires plants to have a petiole base 3 - 6 mm wide. Small petioles southern interior. The site near the White Lake Observatory result in eggs laid in incorrect locations. When temperatures are established from 188 adults and went on to become the collection 0 30 C or more they will lay eggs a much greater rate. source for further populations throughout the province and the United States. The other site near Grand Forks did not establish. At Egg: this time it is determined that the beetle is well established in the The flat, white eggs turn blue-grey during the first 4 - 5 days. Eggs field and no longer requires redistribution efforts. incubate 2 - 4 weeks. Habitat: Larva and pupa: It has been found released and found established in the Bunchgrass, Larvae are white, legless, have a Coastal Douglas-fir, Engelmann spruce-subalpine fir, Interior cedar- large flat head and a segmented hemlock, Interior Douglas-fir, Montane spruce and Ponderosa pines body. First instar larvae feeds biogeoclimatic zones. Dispersal is most frequently found in the between petioles. At the time Bunchgrass, Interior Douglas-fir, and Ponderosa pine zones. when knapweed is setting seed, the second instar larvae mine into Field results: the upper root. The plant reacts by By 1999, 148,248 S. jugoslavica beetles had been released in BC, healing the feeding scars, but the most of which were collected from the original 1976 White Lake larvae continue to feed. The location. Assisted redistribution slowed over time and in 1997 the feeding creates a cavity with last field collection and release was made. dense callus formations that cause the root to swell. They feed on S. jugoslavica is frequently found on spotted knapweed growing in protruding growths of the callus and on plant fluids, filling the the warm to hot knapweed range of the southern interior. It is chamber with frass. At this time they overwinter, bending their found in the same knapweed infestations as many other biocontrol abdomen (head to tail) to form a 'hook'. The larvae pupate the agents. It is commonly found sharing sites with other root feeders following spring within the feeding chamber. Pupation usually including: Pterolonche inspersa, Cyphocleonus achates, and Agapeta occurs from late May to early June. Some slower developing larvae zoegana. It also shares sites with the seedfeeders:Urophora affinis, will resume feeding in the spring until mid July and pupate later U. quadrifasciata, Larinus minutus, and L. obtusus. than most. Pupae are white, moulting into adults in nine days when 0 temperatures are 20 C. They remain in the roots until warm Collection for redistribution temperatures and dry weather arrives in July. Plants rarely support Adults can be collected by sweeping from mid July to mid August. more than one larva, if two develop on a single root, the one New sites need to be where the plants encounter a drought stress feeding lowest in the root will be smaller. They cannot develop on period in summer to ensure survival. Self dispersal of this agent has small rosettes with poor producing vegetation. Larvae can be filled most its desired habitat in the southern interior, leaving little smothered in vigorous rosettes which over-produce callus growth. need to assist with distribution.
Overwintering stage: NOTES Larvae overwinter in roots and pupate the following spring. Slow S. jugoslavica shares habitat and sites with a large host of developing larvae may overwinter, resume feeding in spring and, other knapweed agents. therefore, pupate later than the general population. P. inspersa will feed on S. jugoslavica larvae if they both exist
in the same root. LOCATION AND EFFECTIVENESS OF ATTACK In picloram spray trials, S. jugoslavica failed to establish on Larvae feeding on roots severely impact the plants vigour. When plants that re-grew 2 - 3 years after treatment. larvae mine into a bolting plant, they mine the stem and then the root, 2% of these plants survive the winter. Larvae attack can stop REFERENCES rosette growth and delay bolting for one or two years. Large plants can survive the first year of attack and set bloom and seed, but will
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Harris, P. 2005. Classical biological control of weeds established biocontrol agent Sphenoptera jugoslavica Obenb. Root-gall former. Gov. of Can., Agriculture and Agri-Food Canada. February 15, 2007.
Mason, P. G. and J. T. Huber, (editors). 2002. Biological control programmes in Canada, 1981-2000. CAB International.
MFR STAFF OBSERVATIONS AND COMMENTS Powell, G. W., A. Sturko, B. Wikeem and P. Harris. 1994. Field guide to the biological control of weeds in British Columbia. B.C. Min. For. Res. Prog.
Powell, R. and P. Harris. 1986. Biological control of diffuse knapweed by Sphenoptera jugoslavica (Obenb.). Canadex. Agric. Can. 2 p.
Rees, N. E., Quimbly, Jr., P. C., G. L. Piper, E. M. Coombs, C. E. Turner, N. R. Spencer, L. V. Knutson (editors). 1996. Biological control of weeds in the west.
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BIOLOGICAL CONTROL AGENT: TERELLIA RUFICAUDA (FAB.) The origin of the T. ruficauda population found in BC is not known.
Type of agent: Seed feeding fly History: Status: Secondary on Marsh plume thistle Although no releases were made, T. ruficauda has been found in BC. Status: Tertiary on Canada thistle It was confirmed to be established near Merritt where samples had been collected in 1931 (Canada thistle). Invasive Plant Species Attacked: Canada thistle (Cirsium arvense), Habitat: Marsh plume thistle (C. palustre) Recorded sightings occur in the Interior cedar hemlock biogeoclimatic zone. T. ruficauda is known to exist as far north as DESCRIPTION AND BIOLOGY the Peace River area in northern BC, which is located in the Boreal Adult: white and black spruce zone. The first sighting near Merritt did not The small flies are yellow-orange coloured. They have a dull black have the exact location recorded, therefore the zones it may have mark on their thorax and four large black marks on their abdomen, fallen into could be the Bunchgrass, Interior Douglas-fir, Engelmann making them appear almost completely black. Females can be spruce-subalpine fir, or Montane spruce zones. More recently it was identified by their 3 mm long ovipositor. The leading edges of their identified as an attacking bioagent on marsh plume thistle growing wings have three black marks and another vague mark near the in the Interior cedar hemlock zone. centre of the hindmost edges. Adults emerge from mid to late summer. Females lay one or two eggs or clusters up to seven into Field results: female flower buds one day before they open. After the females There has been very little field sampling of T. ruficauda. Sightings of oviposit, they mark the flowerhead with a fluid to discourage further it are mentioned in conversation, but most recorded information is attack. Eggs deposited into younger or older heads produce smaller not available. Recent observations indicate may be quite common larvae with poor survival rates. The females will lay 1 - 12 eggs/day, on marsh plume thistle. until 50 - 500 have been laid. The quantity of eggs depends on their size, larger females lay more eggs. Females test buds to determine if Collection for redistribution they are male or female. By depositing small batches of eggs into Collections can be made by collecting infested seedheads prior to many heads, the females beat the odds of laying into flowers which adult emergence in late spring or early summer and released to new may be too mature, too small or males. If eggs are mistakenly sites by scattering heads over the site. Care should be taken to deposited into male flowers, the larvae starve with the absence of ensure that the same invasive plant species is the same as the seed. Larger offspring tend to develop when male and female plants infested seedheads to ensure that new invasive plants are not occur on the same site. introduced to sites where the plants may not be already established. The fly has self dispersed and probably requires little assisted Egg: distributions. There is no specific information available regarding eggs or their incubation period. NOTES Formerly known as Orellia ruficauda Fab. Larva and pupa: T. ruficauda may not be able to compete against Larinus Larvae are white, 4 - 6 mm long, and grow to 5 - 7 mg over two planus. weeks. There are three larval instars. The first instar feeds on the Larvae are parasitized by Crataepus marbis and Tetrastichus flower ovary, causing it to enlarge. The second and third instars venustus, which kill third instar larvae. browse through seeds, eating their entire contents. When thistle An unknown pathogen has been described to infect the larvae, seed is ready to fly, the larvae surround themselves with seedhead causing the larvae to become translucent and die just before papus and prepare to overwinter. The larvae will alternately pupation. overwinter in the receptacle when flowers have few seeds. Pupation T. ruficauda attacks globe artichoke, making it a non-desired normally occurs in the spring. In climates with no cold period, adults species in California. emerge in three months.
REFERENCES Overwintering stage: Harris, P. and R. B. Lalonde. 2005. Classical biological control of Mature larvae overwinter in cocoons inside seedheads. weeds established biocontrol agent Terellia (= Orellia) ruficauda
(Fab.) Seed head fly. Gov. of Can., Agriculture and Agri-Food Canada. LOCATION AND EFFECTIVENESS OF ATTACK February 21, 2007 Seed reduction caused by larvae feeding varies with pollination. Generally, 40% of seeds are reduced in each attacked flower head. MFR STAFF OBSERVATIONS AND COMMENTS The fly only attacks early flowers which reduce overall annual seed Lalonde, R. G. 1991. Oviposition behaviour of Orellia ruficauda on production by 2%. Canada thistle. Thesis. Simon Fraser Univer. 14 p.
PREDICTED AND NATIVE HABITAT McFadden, M. W. and R. H. Foote. 1960. The genus Orellia B.-D. in Terellia ruficauda is adventive to North America where it is found in America north of Mexico. In Proc. Entomol. Soc. Wash. Vol. 62, No. a wide variety of Canada thistle habitats. In Canada, it has been 4: 253-261. found in British Columbia, Manitoba, Ontario, New Brunswick and Newfoundland. Its geographic range is all Palaearctic except the south. Its United States distribution is similar, stretching from coast to coast, and into southern California, dating back to 1898.
T. ruficauda occurs in the northern Palaearctic region. This region encompasses all of Europe, the north west coast of Africa and Asia north of the Himalaya Mountains.
BRITISH COLUMBIA EXPERIENCES Origin:
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BIOLOGICAL CONTROL AGENT: UROPHORA AFFINIS FRFLD. nearby stands, however it lacks a host finding ability when it occurs in isolated situations. Type of Agent: Seed feeding fly Status: Tertiary Its native distribution occurs in central and eastern Europe and in Turkey. Invasive Plant Species Attacked: Spotted knapweed BRITISH COLUMBIA EXPERIENCES (Centaurea biebersteinii), Origin: Diffuse knapweed U. affinis populations released in BC originate on spotted knapweed (C. diffusa), growing in the French Rhine Valley between Basel and Mulhouse. Squarrose knapweed
(C. virgata ssp. squarrosa). History:
The first U. affinis release in BC was made in 1970 in the southern DESCRIPTION AND BIOLOGY interior. The earliest releases made during the 1990's and 1980's Adult: were all released in the southern interior. These sites established The 1 - 3 mm long flies have very well and have contributed to agent dispersal. Collections and dark bodies and clear wings releases in the 1990's focussed on moving the flies into new habitats marked with faint dark bars. and they were released into north western BC and onto Vancouver When at rest their wings are Island. The last assisted redistribution effort occurred in 1996. often held close in line with the body. Females can be Habitat: identified by their long, pointed, black ovipositor. Urophora affinis U. affinis releases have been made and found established and/or adults emerge in June and July which coincides with the flower dispersed in the Bunchgrass, Coastal Douglas-fir, Interior cedar budding stage. Adults mate immediately and start to lay eggs hemlock, Interior Douglas-fir, Montane spruce, Ponderosa pine and between immature flower bracts within three days. Each female Sub-boreal spruce biogeoclimatic zones. lays 120 eggs. There is a narrow Egg-laying phase for U. affinis because the host plant floral buds need to be the specific size to Field results: ensure the eggs hatch to coincide with a particular stage necessary U. affinis is commonly found wherever the host plant grows in the for larvae development. southern interior, existing with other seed and root feeding bioagents. Larvae have been found in spotted and diffuse knapweed Egg: seedheads, however it appears to prefer the spotted variety. The eggs incubate for 3 - 4 days. Collection for redistribution Larva and pupa: Adults can be swept and aspirated in June and July. Clipping Creamy white larvae penetrate into the flowerhead and develop knapweed stems with infested seedheads from August to October is into a plump, 'barrel-like' shape. The plant objects to the intruding the most efficient way for large collections, however this method larvae and over 10 - 15 days produces a woody gall around each of can promote the spread of seeds. Tie clipped stems to a stake for them. The galls are lined with nutritive cells, which the larvae feed overwintering to prevent them from blowing away. Best success has upon. After 28 days, all the cells inside the gall will be consumed and been found when U. affinis is transferred to the same invasive plant the larvae development will be complete. Pupations occurs in the species from which it is collected. gall and takes two more weeks or over the winter. The earliest to pupate will emerge as new adults that will go on to produce a NOTES second generation. However most larvae need a cold phase to Each seedhead feeder has specific requirement, allowing multiple bioagents to induce pupation so they will generally overwinter inside the gall and exist in a single seedhead. When occuring on the same sites as U. emerge the following spring when the flower buds are about 3 mm quadrifasciata, U. affinis usually dominates. The two species are more long. Under normal productive in conjunction with other agents than alone. conditions 1 - 2 galls are Spotted knapweed produces few immature buds for Urophora spp. to produce produced in diffuse its second generation within, whereas diffuse knapweed will continue to knapweed, whereas, 2 - 5 produce a succession of flowers until frost. galls are produced in spotted U. affinis is known to also feed on squarrose knapweed (C. virgiata spp. knapweed. The hard galls squarrosa), although this knapweed species is not known to be growing in BC. provide protection for the
larvae and pupae during their development from most REFERENCES other seed-feeding insects. Harris, P. No date. Establishment of Urophora affinis Frfld. and U. quadrifasciata (Meig.) (Diptera: Tephritidae) in Canada for the Overwintering stage: biological control of diffuse and spotted knapweed. Agric. Can. Res. Most larvae will overwinter in woody galls in the seedheads and St., Regina, SK. 22 p. pupate the following spring in May. Harris. P. 1986. Biological control of knapweed with Urophora affinis (Frfld.). Canadex Weed Control Beneficial insects 641.613. Gov. of LOCATION AND EFFECTIVENESS OF ATTACK Can. 2 p. The larvae in the seedheads create hard, woody galls which inhibit
seed production and are capable of reducing seed production by 75 Harris, P. 1989. Feeding strategy, coexistence and impact of insects to 90%. Gall formation depletes root reserves and over time will in spotted knapweed capitula. In Proc. VII. Intern. Symp. Biol. weaken the plants, resulting in fewer and smaller floral stalks. Control Weeds. March 6-11, 1988. Rome, Italy. Pp. 39-47.
PREDICTED AND NATIVE HABITAT Harris, P. 2006. Classical biological control of weeds established U. affinis is adaptable to the wide variety of knapweed habitat. It biocontrol agent Urophora affinis Frfld. and U. quadrifasciata. Gov. does show a preference for mesic sites, appears to do best in wetter of Can., Agriculture and Agri-Food Canada. December 1, 2006 years, and prefers spotted over diffuse. It readily disperses to
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MFR STAFF OBSERVATIONS AND COMMENTS Powell, G. W., A. Sturko, B. Wikeem and P. Harris. 1994. Field guide to the biological control of weeds in British Columbia. B.C. Min. For. Res. Prog.
Rees, N. E., Quimbly, Jr., P. C., G. L. Piper, E. M. Coombs, C. E. Turner, N. R. Spencer, L. V. Knutson (editors). 1996. Biological control of weeds in the west.
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BIOLOGICAL CONTROL AGENT: UROPHORA QUADRIFASCIATA U. quadrifasciata is adaptable to the wide variety of of knapweed habitat. It is less tolerant of severe winter conditions and literature (MEIG.) indicates that it requires considerably more protective snow cover Type of Agent: Seed feeding fly than U. affinis. Diffuse knapweed is better suited to this species Status: Secondary on Meadow knapweed because it continues to produce suitable floral buds over a long Status: Tertiary on Diffuse and Spotted period which coincides with the bioagent's reproductive knapweeds requirements.
Invasive Plant Species Attacked: Its native distribution occurs in Eurasia. Spotted knapweed (Centaurea BRITISH COLUMBIA EXPERIENCES biebersteinii), Origin: Diffuse knapweed (C. U. quadrifasciata populations released in BC originate from diffusa), Caucasus where it occurred on Centaurea sterilis. Black knapweed (C. nigra), History: Brown knapweed (C. The first U. quadrifasciata release in BC was made in 1972 in the jacea), southern interior. Early treatments established very well and have Meadow knapweed (C. contributed to its dispersal. Assisted redistribution continued until debeuxii) 1995.
DESCRIPTION AND BIOLOGY Habitat: Adult: U. quadrifasciata has been found established and dispersed in the The flies measure 1 - 3 mm long. They have black bodies and clear Bunchgrass, Coastal Douglas-fir, Interior cedar hemlock, Interior wings distinctly marked with a black 'UV' pattern. At rest, the adult Douglas-fir, and Ponderosa pine biogeoclimatic zones. Its status at a will hold their wings in a tented formation similar to a 'V'. Females release made in the Sub-boreal spruce zone is unknown at this time. can be identified by their long, pointed, black ovipositor. Adults emerge in late June and July, which coincides with the development Field results: of the knapweed flower buds, and mating begins immediately. U. quadrifasciata is quite common in the southern interior, co- Females start to lay eggs in three days and will continue to do so for existing with other seed and root feeding bioagents. The larvae have three weeks. Eggs are laid into the unopened flower buds that are been found more frequently on spotted knapweed than on the more mature than those preferred by Urophora affinis. U. diffuse and meadow varieties, but this may be a result of more quadrifasciata can oviposit and develop in the same flowerheads as dispersal sampling being done spotted knapweed. U. affinis, but avoid doing so because of the misshapen or delayed bud development that occurs with U. affinis attack. When they do Collection for redistribution co-exist, they do so without harming the other. Second generation Adults can be swept and aspirated in June and July and again in adults appear in mid to late August and will mate and oviposit. August. Clipping knapweed stems with infested seedheads from Adults are capable of dispersing 21 km in five years. September to October or from March to May is the most efficient way for large collections, however this method can promote the Egg: spread of seeds. Tie new clipped stems to a stake for overwintering The eggs incubate for 3 - 4 days. to prevent them from blowing away.
Larva and pupa: Redistribution of flies is rarely necessary as this agent easily Creamy white larvae penetrate into the flower bud and grow into a disperses and readily locates new host sites. plump, 'barrel-like' shape. The entire larvae and pupae stages develop within galls inside the flower bud. The plant objects to the NOTES intruding larvae and reacts by producing a gall around each of them. Each seedhead feeder has specific requirements, allowing By 15 days the galls will have maximized in size. The galls are lined multiple bioagents to exist in a single seedhead. U. with nutritious cells that the larvae feed on. The larvae will have quadrifasciata disperses quicker than U. affinis, but when consumed all but a paper thin occuring on the same site it becomes less dominant. outer layer of the gall in 20 or 25 Nevertheless, they are more effective in conjunction with days. At this time they will begin other agents than alone. to pupate. The larvae turn to face Spotted knapweed produces fewer immature buds for outward and pupate within the Urophora spp. to produce its second generation within, thin gall liner. Adults emerge in 5 whereas diffuse knapweed will continue to produce a - 6 weeks, usually in August. succession of flowers until frost. Multiple U. quadrifasciata larvae U. quadrifasciata is known to also feed on black knapweed (C. can occur in each flower head. nigra), brown knapweed (C. jacaea), squarrose knapweed (C. virgata spp. squarrosa) yellow starthistle (C. soltitialis) and Overwintering stage: cornflower (C. cyanus). Most overwinter as mature larvae in seedhead galls and continue development the following spring. REFERENCES Harris, P. 1986. Biological control of knapweed with Urophora LOCATION AND EFFECTIVENESS OF ATTACK quadrifasciata MG. Canadex Weed Control Beneficial insects Combined U. quadrifasciata and U. affinis can reduce seed 641.613. Gov. of Can. 2 p. production by 95%. The gall formation depletes the plant of nutrient reserves resulting in fewer floral stems. Harris, P. 2005. Classical biological control of weeds established biocontrol agent Urophora affinis Frfld. and U. quadrifasciata. Gov. PREDICTED AND NATIVE HABITAT of Can., Agriculture and Agri-Food Canada. December 1, 2006.
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Harris, P. No date. Establishment of Urophora affinis Frfld. And U. quadrifasciata (Meig.) (Diptera: Tephritidae) in Canada for the biological control of diffuse and spotted knapweed. Agric. Can. Res. St. Regina, SK. 22 p.
MFR STAFF OBSERVATIONS AND COMMENTS Powell, G. W., A. Sturko, B. Wikeem and P. Harris. 1994. Field guide to the biological control of weeds in British Columbia. B.C. Min. For. Res. Prog.
Rees, N. E., Quimbly, Jr., P. C., G. L. Piper, E. M. Coombs, C. E. Turner, N. R. Spencer, L. V. Knutson (editors). 1996. Biological control of weeds in the west.
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BIOLOGICAL CONTROL AGENT: UROPHORA STYLATA F. Urophora stylata is relatively common and is found in a variety of bull thistle habitats. It requires large, dense stands to ensure its Type of agent: Seedhead gall producing fly survival. As grasses replace bull thistle, the fly density decreases. Status: Secondary Grazing or mowing will limit its success.
Invasive Plant Species Attacked: Its native distribution is from Atlantic Europe to western Siberia and Bull thistle (Cirsium vulgare) Kazakhstan and to the south Mediterranean, Afghanistan and Pakistan. It is most common in the west and central parts of DESCRIPTION AND BIOLOGY Northern Europe where bull thistle is most abundant. Adult: Adults have dark bodies BRITISH COLUMBIA EXPERIENCES with vaguely-striped, brown Origin: thoraxes and yellow dots on The U. stylata populations released in BC originate from the Swiss their back. Males measure 4 Jura and upper Rhine Valley, Germany. - 5 mm long while females are up to 8 mm long, including their long, black ovipositor. Their clear wings extend beyond their abdomen History: and are marked with three dark bands (appearing similar to 'I' and In 1973, the first U. stylata releases were made on Vancouver Island 'V'). The flies emerge in early summer, usually by June. The males and into the Fraser Valley. The flies easily established and field claim territories by scent marking areas which does not attract collections began shortly after. Mass redistribution of the flies females, but rather discourages males from intruding. Females continued until 1996 when the demand for bull thistle control remain withdrawn and in hiding until the plants set buds suitable for appeared to subside. In 2001 there was a renewed interest to oviposition. Suitable floral buds are 6 - 13+ mm, (90% are laid in redistribute the agent. The last recorded assisted redistribution buds 8 - 11 mm) and are those growing on branching terminals. effort occurred in 2006. Males seek females on suitable floral buds to mate. Females position themselves horizontally on the thistle spines and deposit Habitat: the eggs singly or in multiples between bud bracts. The females then U. stylata have been released and found established and/or leave the bud and move to another where the mating and dispersed in the Coastal Douglas-fir, Coastal western hemlock, oviposition procedure is repeated. Other females may use the same Interior cedar hemlock, Interior Douglas-fir, Montane spruce, bud, however exact bud size limits this practice and, therefore, Ponderosa pine and Sub-boreal spruce biogeoclimatic zones. avoids potential excessive use of floral buds. Adults live for about two months. Field results: U. stylata have been found at all the initial treated sites and at Egg: substantial distances from known release locations. When sites The white, 0.7 x 0.2 mm eggs incubate for 5 - 8 days. were monitored in 2002 and 2003 many sites had no plants or few plants remaining. Rarely have bull thistle infestations been found Larva and pupa: without U. stylata attack. In one BC study, the average seed Typical barrel-shaped reduction is about 60%. The larvae of both U. stylata and larvae are plump, creamy Rhinocyllus conicus have been found occupying the same bull thistle white, with dark, flat seedhead. posteriors. When mature they will be 3 - 5 mm long. Collection for redistribution The first instar develops Galled heads can be collected from the field from late August to within the egg. The newly November. Attacked heads are easily detected by their misshapen hatched second instars indentations and when squeezed they are hard, whereas vacant consume the egg shell seedheads are soft. Redistribute collections on the ground at new then feed their way locations in the fall, winter or early the following spring. Clipped toward the developing, enlarging seeds. In mid summer (late July to seedheads can also be held overwinter at 40C, keeping refrigerated early August), the larvae locate themselves below the seeds. Larvae galls moist while not allowing them to become moudly. The presence promote the plants to develop chambers (one per larva) following spring, the galls can be scattered at the new site, allowing lined with cells that become food souces for the larvae. The adults to exit and disperse on their own. New colonies can develop chambers grow into hard woody shells. When multiple larvae are in from 20 - 50 galled seedheads. the same flowerhead, the chambers fuse to become a large woody gall, with a single larva in each chamber. The third instars fit tightly, NOTES face down in their chambers and using their hard anal plate to block Competing Rhinocyllus conicus also attacks bull thistle. The the exit, they overwinter. In late April to early May the larvae turn beneficial contribution the two make together outweighs to face the exit and prepare to pupate. A brown cocoon develops competition. around each larva and pupation completes in June. Three to 20 No longevity study has been completed. larvae may be present in each head.
Overwintering stage: Larvae overwinter in their third instar in REFERENCES woody galls inside flowerheads. Harris, P. 2005. Classical biological control of weeds established biocontrol agent Urophora stylata F. Seed-head gall fly. Gov. of Can., LOCATION AND EFFECTIVENESS OF ATTACK Agriculture and Agri-Food Canada. February 13, 2007
Larvae presence in flowerheads cause decreased seed production. Harris, P. and A. T. S. Wilkinson. 1986. Biological control of bull The gall formation strains plant nutrients, causing fewer thistle with Urophora stylata Fabr. Canadex, Agric. Can. 2 p flowerheads and reduces plant vigour. Seeds directly above the gall
become enlarged and non-viable and most seeds beyond the gall Kelleher, J. S. and M. A. Hulme, (editors). 1984. Biological control also fail to develop. Studies indicate 60 - 90% of seedheads are programmes against insects and weeds in Canada 1969-1980. attacked, where 90% of the seed is reduced. Commonwealth Agricultural Bureaux.
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MFR STAFF FIELD OBSERVATIONS. Powell, G. W., A. Sturko, B. Wikeem and P. Harris. 1994. Field guide to the biological control of weeds in British Columbia. B.C. Min. For. Res. Prog.
Rees, N. E., Quimbly, Jr., P. C., G. L. Piper, E. M. Coombs, C. E. Turner, N. R. Spencer, L. V. Knutson (editors). 1996. Biological control of weeds in the west.
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