THE CITY OF SAN DIEGO PARK AND RECREATION DEPARTMENT OPEN SPACE DIVISION MIRAMAR RANCH NORTH MAINTENANCE ASSESSMENT DISTRICT APRIL 2014 STAFF REPORT ______

Ornamental Landscaping

 Please contact Grounds Maintenance Manager Jaime Diez if you have suggestions on ways to improve maintenance activities within the district.

Tree Trimming

 West Coast Arborist will finish trimming trees by March 28 in the major monument corners and in the center medians along Scripps Poway Parkway from interstate 15 to the Poway City Limits. During the early March storm the MAD lost 14 mature trees throughout the district due to possible over saturation of soil in a short amount of time and/or canopy weight. More frequent trimming of the trees canopies could help prevent future failures during winter storms.

Mini-Parks

 After inspections by two arborists and research by City staff it appears that several eucalyptus trees at Oak Glen Mini Park are suffering from infestations of Red shoulder Bugs and Tortoise Beatles. Staff is working with Blue Skies to address the issue and is also investigating other possible scenarios that may be impacting the overall health of the trees including soil conditions.

Landscape Contract

 Blue Skies continues to provide services within budget.

Respectfully submitted,

Jaime Diez Grounds Maintenance Manager (619) 685-1306 [email protected] cc: Casey Smith, District Manager, Open Space Division Paul Sirois, Assistant Deputy Director, Open Space Division Eucalyptus leaf beetle (Chrysophtharta m-fuscum) ‰ Recently (August 2003) found on landscape trees in N Tustin, Orange Co.; probably native to Australia. ‰ Host: Blue gum eucalyptus (Eucalyptus globulus). ‰ Field ID: Adults about 5-7 mm long, gray to reddish brown, hemispherical and flattened underneath. Legs with fourth tarsomere bilobed and covered ventrally with a thick set of bristles. Larva greenish-gray, caterpillar-like, with head and thoracic legs black, and a pair of fleshy eversible defense glands on dorsum of abdominal segment 8; larvae feed on the young waxy growth of host plant. Elliptical, orange eggs laid in rows on the underside of leaves. Both adults and larvae are covered with a whitish pruinescence that helps camouflage them with the leaves on which they feed. Similar to Australian tortoise beetle (ATB), from which it can be distinguished by lighter color (both adult and larva of ATB are dark brown). Pupae bright yellow, probably in ground litter underneath the tree.

Life size

adult

bilobed tarsus

eggs larva everted glands pupa

Damage on young growth of E. globulus

Prepared by Natalia von Ellenrieder, Research Associate, California State Collection of Arthropods, September 2003 Eucalyptus Longhorned Borers

Integrated Pest Management for Home Gardeners and Landscape Professionals

Two closely related species of long- in the number of hairs on their anten- horned borer beetles (family Ceram- nae and their wing color. For example, bycidae) attack eucalyptus trees in dark brown predominates on the wing California. Phoracantha semipunctata covers of P. semipunctata, while yellow (Fig. 1), which is native to Australia, to cream color predominates on wing was introduced into Southern Califor- covers of P. recurva (Table 1). nia in the 1980s. It rapidly became a pest and now appears throughout the Several nights after emerging from state wherever eucalyptus trees grow. infested wood and mating, the female Natural enemies were introduced from beetles of P. semipunctata begin laying Australia, and biological control com- eggs in groups of 3 to 30 beneath the Figure 1. Adult eucalyptus longhorned borers, (left) bined with improved cultural care of loose bark or in crevices on bark sur- Phoracantha semipunctata and P. recurva. eucalyptus have dramatically reduced faces of eucalyptus trees. Females can the number of trees this borer kills live 1 or more months and lay up to 300 each year. eggs, which hatch in about 1 to 2 weeks depending on temperature. In 1995, a second species of longhorned borer, Phoracantha recurva (Fig. 1), was After hatching, larvae bore directly into discovered in Southern California the inner bark, or they feed temporarily in Los Angeles, Riverside, Orange, on the bark surface before boring in. If and San Bernardino counties. This feeding on the surface, outward from beetle has spread throughout much of the egg mass they leave a distinct, dark 1 California wherever eucalyptus grows. trail /4 inch to several inches long that Figure 2. Dark trails made by young However, biological control has been scores the bark surface (Fig. 2). Most eucalyptus longhorned borer larvae. less effective against this new borer. P. larval feeding occurs in the cambium, recurva, along with several other new the thin layer of tissue on the bark’s pests, can stress and kill eucalyptus. inner surface. There larvae bore gal- leries that can extend several feet (Fig. Freshly cut wood, dying limbs, and 3). In trees with heavy infestations, the trees suffering from stress, especially scraping sounds the developing larvae drought stress, attract both of these make while chewing in the cambium beetles. Many eucalyptus trees in Cali- are audible from a distance of several fornia grow in unmanaged or mini- feet. mally managed environments with no irrigation. Eucalyptus species that At the end of the feeding period, larvae grow in wetter areas of Australia have excavate pupal chambers in the wood. Figure 3. Peeling back this tree’s bark reveals galleries mature larvae made. been planted in California, so when They enter the chambers, packing the they experience prolonged dry periods, these species are especially susceptible Table 1. Differences Between Two Eucalyptus Longhorned Borers in California. to being attacked and killed by borers. Characteristic Phoracantha semipunctata Phoracantha recurva Color of wing Mostly dark brown; a zigzag Mostly cream to yellowish with IDENTIFICATION AND LIFE covers (elytra) line bisects the cream-colored dark brown areas primarily CYCLE area in the middle limited to the rear third Adults of the two Phoracantha species Golden hairs on the None to sparse Long and dense resemble each other. Their antennae underside of each antenna segment are as long as or longer than their body, Sources: Gill, R. J. 1997. An Australian eucalyptus beetle. California Plant Pest and Disease Report. 16(1–2):12; and and the antennae of the males have Hanks, L. M., T. D. Paine, J. G. Millar, and C. Campbell. Another tree-killing pest of eucalyptus invades California. prominent spines. They differ, however, California Plant Pest and Disease Report. 16(1–2):19–21.

EST OTES Publication 7425 PUniversity of California N Statewide Integrated Pest Management Program Agriculture and Natural Resources September 2009 September 2009 Eucalyptus Longhorned Borers

holes behind them with frass (excre- dry leaves, and the bark is cracked and the summer when insect pests are most ment) and wood shavings (Fig. 4). Lar- packed with larval excrement. Infested active. Suddenly cutting off irrigation vae require about 70 days to develop in trees usually die within of a few weeks to trees that have been receiving water fresh wood or logs during hot summer of girdling, although resprouting can regularly will cause trees to become months and up to 180 days in drier logs. occur from the tree base. water stressed and susceptible to Only relatively fresh logs sustain beetle heavy attack. If irrigating, apply water larvae; old, dry logs are too hard for MANAGEMENT to the ground below the edge of the larvae to feed on and then successfully You can use the same methods to man- outer canopy and not in close near the develop. Mature larvae can be more age both Phoracantha species—reduce trunk. Avoid frequent, shallow water- than 1 inch long and are cream colored tree stress, properly handle eucalyp- ing, which often occurs for lawns. Such and legless. tus wood, plant resistant species, and a watering schedule is likely to promote avoid activities that disrupt biological tree root disease. Following pupation, adult beetles control. Pesticide applications gener- emerge from the same holes by chew- ally aren’t effective in managing these ing through the frass plugs. During spring and summer, the beetle requires pests. 3 to 4 months to complete its life cycle, but starting in fall and winter it can Cultural Management require up to 9 months. There are two Certain species of eucalyptus are more and possibly three overlapping gen- resistant to longhorned borers, espe- erations a year. Larvae can be present cially those adapted to drier conditions anytime during the year, and adults (Table 2). Be aware that a few species can emerge from pupae anytime from such as blue gum (Eucalyptus globulus) April through October. have become invasive, and other spe- Figure 4. Mature larva of the eucalyptus cies can be better choices for planting longhorned borer in a cross section of a The life cycle of P. recurva differs depending on the area you live in. Also, tunnel. Note that frass packs the entry way. somewhat from that of P. semipunctata. longhorned borers can attack any spe- P. recurva develops more quickly and cies of eucalyptus if trees are heavily Figure 5. completes a generation in a shorter stressed, such as when planted in poor Holes in period of time. P. recurva adults can be soil or deprived of sufficient water. A trunk ooze with sap, present for a longer period during the well-maintained tree of a susceptible year and emerge as early as February. a common species can be at less risk of infesta- sign of tion than a neglected tree of a resistant a long- DAMAGE species. horned Holes in the bark and stains or oozing borer in- liquid on limbs or trunks are common Consider providing supplemental festation. symptoms of longhorned borer dam- water on a regular schedule during age (Fig. 5). Foliage can discolor and prolonged dry periods, particularly wilt, and limbs can die back. Long- if seasonal rainfall has been below horned borers usually attack stressed normal. If a tree has received regular or damaged plants, leaving vigorous, irrigation, avoid prolonged interrup- appropriately watered trees alone. In tions to watering, particularly during California, however, many eucalyptus trees are seasonally water stressed dur- Table 2. Relative Susceptibility of Eucalyptus Species to Phoracantha semipunctata. ing hot summer months, rendering a More susceptible More resistant significant proportion of them suscep- tible to beetle attack. Tree species with blue gum, E. globulus hybrid, E. trabutii some resistance to these wood borers flooded gum,E. grandis lemon gum, E. citriodora can produce copious amounts of resin Karri gum, E. diversicolor mountain gum, E. dalrympleana in response to an attack. manna gum, E. viminalis red ironbark, E. sideroxylon Extensive larval feeding beneath the round leaved/red flowered,E. platypus/nutans river red gum, E. camaldulensis bark can spread around the entire cir- shining gum, E. nitens sugar gum, E. cladocalyx cumference of a tree, girdling, or com- Sydney blue gum, E. saligna swamp mahogany, E. robusta pletely removing a strip of bark from, Adapted from Hanks, L. M., T. D. Paine, J. G. Millar, and J. L. Hom. 1995. Variation among Eucalyptus species the trunk. Trees at this stage of infesta- in resistance to eucalyptus longhorned borer in southern California. Entomologia Experimentalis et Applicata. tion have a thin canopy with wilted or 74:185–194.

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The specific amount and frequency of Alternatively, solarize wood by placing water needed vary greatly depending it in a sunny location and covering it on the site and tree species. A general with ultraviolet-resistant plastic. This recommendation is to irrigate eucalyp- prevents new beetles from attacking tus trees infrequently (possibly once and resident beetles from emerging a month during drought periods) but and flying to nearby living eucalyptus. with sufficient amounts so the water You can store properly solarized wood penetrates deeply into the soil (1 foot for firewood. or more below the surface). You can achieve this by applying water slowly To solarize, tightly seal wood beneath thick (10 mil), clear plastic sheets in a Figure 6. Healthy (yellow) and parasit- through drip emitters that run continu- ized (orange) eggs. ously for several days. In areas without sunny location for several months. To an established irrigation system, you be effective, this treatment requires P. recurva. Conserve parasites by avoid- can use a water tank truck to tempo- keeping wood piles small; using high- ing the spraying of eucalyptus bark or rarily flood soil. However, avoid pro- quality, clear plastic resistant that is to ultraviolet light degradation; thor- foliage with broad-spectrum, persistent longed waterlogging, especially around oughly sealing the edges; and promptly insecticides. the root crown, because eucalyptus patching holes to prevent beetles from trees are susceptible to pathogens that escaping. For more information on so- Figure 6 shows an example of healthy, cause Armillaria and Phytophthora larization, see the publications by Don- yellow eggs compared to parasitized root rots. aldson and Seybold (1998) and Sanborn eggs. (1996) in References. Protect trees from injuries. Remove infested trees and branches immedi- Biological Control ately, but do all other pruning during OTHER EUCALYPTUS December and January when adult Biological control with natural enemies PESTS Several other introduced insects also beetles aren’t present. When planning has provided a partial solution to attack eucalyptus. Pest managers extensive limb removal for reasons longhorned borer problems. At least one native California wasp, Helcostizus should learn how management methods other than removing dead wood or such as conserving natural enemies rufiscutum (Ichneumonidae), parasit- eliminating hazardous trees, space the and planting resistant species can izes P. semipunctata but only rarely; trimming over several years. Other- help control these pests, which include consequently, an egg parasite has been wise, the tree might not have adequate leaf-feeding beetles (tortoise beetles), introduced from Australia for biologi- eucalyptus gall wasps, and at least six foliage to produce the food it needs to cal control. species of psyllids. maintain good health. Also, extensive pruning suddenly exposes previously Some of these insects now are now un- The wasps are highly specialized para- shaded bark to direct sunlight, which der effective biological control, including sites, attacking only certain beetles. can result in sunburn (sunscald) can- the bluegum psyllid (Ctenarytaina eu- They present no threat to humans, pets, calypti), the eucalyptus snout beetle or kers that are susceptible to borer attack. or livestock. By reducing beetle popula- gumtree weevil (Gonipterus scutellatus), tions to a lower level, natural enemies and especially in Southern California Eucalyptus logs used for firewood and have reduced borer damage, because the eucalyptus redgum lerp psyllid (Gly- dead or dying branches and trees are vigorous trees can survive a few at- caspis brimblecombei). Inappropriate actions such as spraying persistent, the beetles’ primary breeding sites. tacks. Sanitation is critical for reducing beetle broad-spectrum insecticides—those that remain in the environment at levels numbers. Until the wood dries below a The egg parasite is Avetianella longoi toxic to natural enemies for more than critical level, it remains highly attrac- (family Encyrtidae), a 1/16-inch-long, a few days—can harm natural enemies tive to egg-laying beetles. Anything host-specific, introduced wasp that lays and can cause outbreaks of these other you can do to speed the drying process, its eggs within the eggs of the beetles. pests. such as cutting and splitting wood Parasitized eggs develop brown shells For more information, see: and, even more importantly, remov- through which you can observe the • Pest Notes: Psyllids. http://www.ipm. ing bark from felled logs, helps reduce body and dark eye spots of developing ucdavis.edu/PMG/PESTNOTES/ the length of time it can support beetle wasps. A. longoi disperses rapidly and pn7423.html development. If infestation already efficiently finds borer eggs. This wasp • Pest Notes: Eucalyptus Redgum Lerp has occurred, you should treat or has become widely established in Cali- Psyllid. http://www.ipm.ucdavis.edu/ PMG/PESTNOTES/pn7460.html; and destroy the wood. Bury, burn (where fornia, typically attacking and killing • Pest Notes: Eucalyptus Tortoise permitted), or chip infested eucalyptus. more than 90% of P. semipunctata eggs Beetles. http://www.ipm.ucdavis.edu/ Chipped eucalyptus makes an excellent in the field. However, it is less effective PMG/PESTNOTES/pn74104.html. mulch. against the more recently introduced

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Chemical Control Early work from both California and other regions where beetles have be- come established indicated insecticides might not be suitable for managing eu- calyptus longhorned borer populations, but more recent studies indicate newer, systemic insecticides (compounds that move within trees after being applied to the soil) might protect individual trees if applied before beetle colonization. Ex- ercise care when using any insecticide, because of the potential for drift, envi- ronmental impact, effects on beneficial or nontarget insects, and risk of expo- sure to humans in urban environments. AUTHORS: T. D. Paine, Entomology, UC University of California scientists and other Riverside; S. H. Dreistadt, UC Statewide qualified professionals have anonymously peer reviewed this publication for technical accuracy. The IPM Program, Davis; and J. G. Millar, Ento- Borer management must focus on bio- ANR Associate Editor for Urban Pest Management mology, UC Riverside. managed this review process. logical control and cultural practices To simplify information, trade names of products and environmental conditions that TECHNICAL EDITOR: M. L. Flint have been used. No endorsement of named products favor the tree to the disadvantage of is intended, nor is criticism implied of similar products EDITOR: M. L. Fayard that are not mentioned. the beetle. Because natural enemy in- This material is partially based upon work troductions by government agencies supported by the Extension Service, U.S. Department ILLUSTRATIONS: Figs. 1–3 and 5–6, J. K. of Agriculture, under special project Section 3(d), and university scientists are funded Clark; Fig. 4, P. Svihra. Integrated Pest Management. through taxes, public and professional support is critical to the ongoing suc- Produced by UC Statewide cess of biological control. Integrated Pest Management Program University of California, Davis, CA 95616 REFERENCES This and other Pest Notes are available at www.ipm.ucdavis.edu. Donaldson, S. G. and S. J. Seybold. 1998. Thinning and Sanitation: Tools for the For more information, contact the University of Management of Bark Beetles in the Lake Ta- California Cooperative Extension office in your county. See your telephone directory for addresses University of California hoe Basin. Reno: Univ. of Nev. Coop. Ext. and phone numbers, or visit http://ucanr.org/ce.cfm. Agriculture and Natural Resources Program Publ. FS-98-42. Also available online, http://www.unce.unr.edu/publications/ WARNING ON THE USE OF CHEMICALS files/ho/other/fs9842.pdf. Accessed Pesticides are poisonous. Always read and carefully follow all precautions and safety recommendations given on the container label. Store all chemicals in the original, labeled containers in a locked cabinet or shed, Sept. 9, 2009. away from food or feeds, and out of the reach of children, unauthorized persons, pets, and livestock. Pesticides applied in your home and landscape can move and contaminate creeks, rivers, and oceans. Dreistadt, S. H., J. K. Clark, and M. L. Confine chemicals to the property being treated. Avoid drift onto neighboring properties, especially gardens containing fruits or vegetables ready to be picked. Flint. 2004. Pests of Landscape Trees and Do not place containers containing pesticide in the trash or pour pesticides down the sink or toilet. Either use Shrubs: An Integrated Pest Management the pesticide according to the label, or take unwanted pesticides to a Household Hazardous Waste Collection site. Contact your county agricultural commissioner for additional information on safe container disposal and Guide. Oakland: Univ. Calif. Div. Agric. for the location of the Household Hazardous Waste Collection site nearest you. Dispose of empty containers Nat. Res. Publ. 3359. by following label directions. Never reuse or burn the containers or dispose of them in such a manner that they may contaminate water supplies or natural waterways. Paine, T. D., J. G. Millar, and L. M. Hanks. 1995. Integrated program pro- NONDISCRIMINATION STATEMENT The University of California prohibits discrimination or harassment of any person on the basis of race, tects trees from eucalyptus longhorned color, national origin, religion, sex, gender identity, pregnancy (including childbirth and medical conditions borer. Calif. Agric. 49(1): 34–37. related to pregnancy or childbirth), physical or mental disability, medical condition (cancer-related or genetic characteristics), ancestry, marital status, age, sexual orientation, citizenship, or service in the uniformed services (as defined by the Uniformed Services Employment and Reemployment Rights Act of Sanborn, S. R. 1996. Controlling Bark 1994: service in the uniformed services includes membership, application for membership, performance of Beetles in Wood Residue and Firewood. service, application for service, or obligation for service in the uniformed services) in any of its programs or activities. Sacramento: Calif. Dept. of Forestry University policy also prohibits reprisal or retaliation against any person in any of its programs or activities and Fire Protection, Tree Notes 3. Also for making a complaint of discrimination or sexual harassment or for using or participating in the investigation available online, http://ceres.ca.gov/ or resolution process of any such complaint. University policy is intended to be consistent with the provisions of applicable State and Federal laws. foreststeward/pdf/treenote3.pdf. Ac- Inquiries regarding the University’s nondiscrimination policies may be directed to the Affirmative Action/ cessed Sept. 9, 2009. v Equal Opportunity Director, University of California, Agriculture and Natural Resources, 1111 Franklin Street, 6th Floor, Oakland, CA 94607, (510) 987-0096.

◆ 4 of 4 ◆ EUCALYPTUS TORTOISE BEETLES Integrated Pest Management for Home Gardeners and Landscape Professionals

Two species of eucalyptus leaf beetles bined stress from multiple pests, espe- from Australia, also called tortoise cially if growing conditions or tree beetles (family Chrysomelidae), care practices are not optimal, could have been introduced into Califor- eventually lead to tree death. nia. Trachymela sloanei was found in 1998 in Riverside County and now Chrysophtharta m-fuscum is a serious occurs throughout most areas of pest of commercially grown baby blue California where eucalyptus trees eucalyptus (Eucalyptus pulverulenta). grow. Chrysophtharta m-fuscum was Baby blue, also called silverleaved discovered in Orange County in 2003 mountain gum, is used as fresh cut and has spread to at least four nearby foliage in flower arrangements, or it counties. is dried, dyed, and sold in preserved arrangements. Notched eucalyptus leaves are usually the only obvious indication that trees The eucalyptus species preferences of are infested by tortoise beetles. Well- these tortoise beetles have not been established and properly maintained well documented. However, certain eucalyptus appear to tolerate exten- tree species are apparently preferred sive leaf feeding. Thus, no tortoise or avoided by these beetles and other beetle control is needed in many land- major eucalyptus pests, as summa- scape situations, despite the tattered rized and compared in Table 1. Figure 1. Eucalyptus tortoise beetle appearance of leaves. Providing trees adults and larvae chew irregular with a good growing environment and IDENTIFICATION notches along leaf edges. appropriate cultural care are usually AND LIFE CYCLE the most important actions for keeping The two species of tortoise beetles The larvae of both tortoise beetle spe- eucalyptus healthy. have similar biology and appearance. cies superficially resemble caterpillars (larvae of butterflies and moths) or DAMAGE By comparison, Trachymela sloanei adults are dark brown with blackish larvae of sawflies but can be distin- Adult beetles and larvae chew semicir- Chrysophtharta m- guished by their appendages. Cater- cular holes or irregular notches along mottling, whereas pillars, larvae of leaf beetles (tortoise edges of eucalyptus leaves (Fig. 1). The fuscum adults are lighter colored and beetles) and sawflies all have three beetles can remove most of a leaf’s gray to reddish brown. Adults of both pairs of true jointed legs on their tho- surface, leaving only the midvein, and species are hemispherical (like half 1 3 a sphere) or rounded, about /4 to /8 rax. Caterpillars and sawfly larvae also they occasionally feed on new termi- have several pairs of prolegs (fleshy, nal growth. Unsightly, tattered leaves inch long, and superficially resemble a large lady beetle. round, leg-like protuberances) on their are usually just an annoyance that abdomen. By contrast, tortoise beetle does not appear to threaten eucalyp- tus survival or health. Female Trachymela sloanei lay 5 to 40 or more eggs side by side on leaves or During heavy infestations, trees under loose bark. The eggs are pink- can lose most of their leaves, which ish or light brown at first and become increases tree stress. Although these orange or dark brown to purplish as they age. Female Chrysophtharta m-fus- (actual beetles alone are not known to kill size) trees, their feeding adds to that of cum lay 1 to 40 or more eggs side by more than a dozen other new eucalyp- side or in an irregular group on leaves. tus pests introduced into California Eggs are bright orange when laid and Figure 2. Trachymela sloanei adult during the last three decades. Com- become dark brown before hatching. (left) and larva (right).

EST OTES Publication 74104 PUniversity of California N Agriculture and Natural Resources January 2009 JanuaryJanuary 20092009 EucalyptusEucalyptus Tortoise Tortoise Beetles Beetle

larvae do not have any prolegs on their Table 1. Approximate Susceptibility of Eucalyptus (Gum) Species to Several abdomen (Fig. 2). Introduced Pests in California.

Common name Eucalyptus Longhorned Redgum Tortoise Trachymela sloanei larvae are dark green (gum) species borers1 lerp psyllid2 beetles3 to reddish brown with a black head and prothoracic shield (black area on Australian beech, polyanthemos — L L the top and sides of the first segment silver dollar behind the head). Chrysophtharta m- baby blue, silverleaved pulverulenta — L4 M5 fuscum larvae are lighter greenish gray mountain with a black head. Larval color in both blue6 globulus M I–L4 M5 species resembles that of host foli- age, camouflaging the larvae. Larvae desert rudis — M I develop through four immature stages dollar leaf, silver dollar cinerea — L — before pupating beneath loose bark, or flooded grandis I I M they drop from the canopy to pupate in the soil or litter around the base forest red tereticornis — M — of host trees. During warm weather, gray ironbark paniculata — L — development time from egg to adult hybrid trabutii L — — may be as short as 5 weeks. There are Karri diversicolor M I — several generations per year from late winter through fall. lemon citriodora L I 7 L long flowered macandra — I — Trachymela sloanei larvae and adults manna viminalis M I M5 hide under loose bark during the day mountain dalrympleana L — — and feed primarily at night. Also, they may be concentrated high in the tree, narrow leaved spathulata — L — so determining the cause of damage Nichol’s willow leaved nicholii — I — may be difficult. If no leaf-feeding red flowering ficifolia — L L adults or larvae are observed on foli- age, search beneath loose bark where red ironbark sideroxylon L I–L L adults, egg masses, larvae, and pos- river red camaldulensis L M M sibly pupae can be observed and col- round leaved/red flowered platypus/nutans M I–L — lected for identification by your local shining nitens M M–I — county department of agriculture or University of California Cooperative silver crenulata — — L Extension office. spotted maculata — —7 L sugar cladocalyx L I–L — Adults and larvae of Chrysophtharta swamp mahogany robusta L L — m-fuscum rest during the day on leaves, where they are easily overlooked Sydney blue saligna M L — because of their color and inactivity. white ironbark leucoxylon — I — The young larvae often occur in groups on leaves, but as they mature and feed — = information not available more they disperse. Adults of both M = more or most susceptible species are commonly snared in spider I = intermediate susceptibility webbing under bark and in orb weaver L = less or least susceptible or reportedly not attacked spider webs.

1 Longhorned borers = reported susceptibility to Phoracantha semipunctata, which is believed to be similar to the Another Leaf Chewer—the Eucalyp- susceptibility to Phoracantha recurva. tus Snout Beetle. The tortoise beetles 2 Redgum lerp psyllid = Glycaspis brimblecombei. described above can readily be distin- 3 Tortoise Beetles = based mostly on observations of Trachymela sloanei, except where footnoted #5. guished from the only other eucalyp- 4 Susceptible to bluegum psyllid (Ctenarytaina eucalypti), but this psyllid is generally under good biological control. tus leaf-chewing beetle in California, 5 More or most susceptible to the Chrysophtharta m-fuscum tortoise beetle. the eucalyptus snout beetle or gumtree 6 Has become an invasive weed, others species may be better choices for planting. weevil (Gonipterus scutellatus). Euca- 7 Susceptible to lemongum psyllid (Cryptoneossa triangula) and spottedgum lerp psyllid (Eucalyptolyma maideni). lyptus snout beetle adults are reddish Adapted partly from: Brennan et al. 2001, Hanks et al. 1995. brown weevils. Their elongated head and mouthparts (their “snout”), are

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apparent when they are viewed from providing trees with supplemental to drought or other factors until trees the front or side. The legless snout water during periods of prolonged become affected by additional dam- beetle larvae are yellowish green with drought, such as during summer aging influences, such as abundant a slimy coating. Young snout beetle and fall in much of California. Some insects. Be aware that a few species larvae feed by scraping leaf surfaces, eucalyptus species are drought toler- such as blue gum (Eucalyptus globulus) leaving discolored trails of tissue and ant, but others require supplemental have become invasive and other spe- causing elongated holes in the center moisture. If irrigating, avoid the cies may be better choices for planting. of leaves. This feeding pattern (surface frequent, shallow watering that is Consult Table 1 for a list of the approx- scraping and holes) by young snout often used for lawns. A general recom- imate susceptibility of eucalyptus beetle larvae is distinctly different mendation is to irrigate eucalyptus species to tortoise beetles, longhorned from the leaf-edge notching caused trees infrequently (possibly once a borers, and psyllids. by tortoise and leaf beetles or by older month during drought periods) but snout beetle larvae, which chew the with sufficient amounts so the water Biological Control margins of leaves and consume large, penetrates deeply into the soil (1 foot Eucalyptus tortoise beetles are not irregular patches of leaf tissue. or more below the surface). This can normally pests in their native home of be achieved by applying water slowly Australia except in cultivated stands; Eucalyptus snout beetles are uncom- through drip emitters that run con- presumably natural enemies there mon in California, because it is under tinuously for several days. In areas keep beetle populations low. During good biological control from an egg without an established irrigation sys- a period of several years, University parasite (Anaphes nitens) introduced tem, a water tank truck can be used of California scientists introduced by University of California scientists. to temporarily flood soil. However, an egg parasite (Enoggera reticulata), Where this weevil is newly intro- avoid prolonged waterlogging, espe- originally from Australia, into Califor- duced, a temporary outbreak may cially around the root crown, because nia in an effort to control Trachymela occur. Avoid applying pesticides and eucalyptus trees are susceptible to sloanei. This tiny wasp searches under tolerate snout beetle leaf damage until pathogens that cause Armillaria root eucalyptus bark and in cracks and fis- the population of natural enemies rot and Phytophthora root rot, which sures, laying its eggs in tortoise beetle increases enough to provide biological are favored by wet soils. The spe- eggs. The parasite larva feeds inside control. From then on, the snout beetle cific amount and frequency of water and kills the egg and, after pupating, should not be a problem. needed vary greatly depending on the emerges as an adult to seek and attack site and tree species. In addition, if a more beetle eggs. MANAGEMENT tree has been irrigated regularly, avoid Eucalyptus trees are attacked by sev- prolonged interruptions to watering, However, the parasite has not been eral other types of insects, including particularly during the summer when recovered during field surveys in eucalyptus longhorned borers, several insect pests are most active. California, indicating the species psyllids, and more innocuous species probably has not become established. such as the lemongum gall wasp (Epi- Avoid fertilizing eucalyptus. Succu- To date, no biological control research chrysocharis burwellii). For more infor- lent new shoot growth stimulated by has been conducted for the newer pest, mation on these pests, see the Pest excess nitrogen can increase the popu- Chrysophtharta m-fuscum. The parasite Notes listed in References. Some euca- lation and damage of eucalyptus-feed- Enoggera reticulata did establish and lyptus insects are now under good ing psyllids. Eucalyptus in landscapes control another eucalyptus tortoise biological control, including eucalyp- rarely require nitrogen fertilization for beetle species in South Africa, and tus snout beetle, bluegum psyllid (Cte- good growth. A six-year study of river several other eucalyptus pests have narytaina eucalypti), and (increasingly red gum found no significant effect been controlled in California using at least in Southern California) the on tree size or survival due to annual introduced parasites. redgum lerp psyllid. Learn how man- nitrogen application. If other plants agement efforts may affect these intro- within the drip line of the tree require Chemical Control duced pests before taking any actions fertilization, use slow-release nutrient There is no published research con- against these leaf-feeding beetles (See formulations. ducted in landscapes on pesticide sidebar.). Provide trees with good cul- effectiveness for controlling eucalyp- tural care and avoid actions that are Pest-Resistant Eucalyptus. If planting tus tortoise beetles. Based on studies harmful to the natural enemies of any eucalyptus, choose species that are of these pests in field nurseries and of these eucalyptus pests. well adapted to the location, including eucalyptus stands, long–term con- tolerance to the prevailing moisture trol can be achieved by a soil drench Cultural Control conditions. Although certain eucalyp- application of the systemic neonicoti- Minimize tree stress by providing tus trees are drought tolerant, other noid insecticides imidacloprid (Merit eucalyptus trees with proper cultural species are adapted to more moist or Bayer Advanced 12-month Tree & care and protecting them from injury. conditions. It may not be apparent Shrub Insect Control) or clothianidin Depending on the situation, consider that eucalyptus trees are stressed due (Arena—for commercial applicators

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only). Foliar sprays of broad-spec- IPM for Eucalyptus Tortoise Beetles trum insecticides such as the carba- mate carbaryl (Sevin) or pyrethroids, Combine several practices in an Integrated Pest Management program including cyfl uthrin (Tempo) and to prevent damage from tortoise beetles and other pest insects on permethrin (Astro, Dragnet), are eucalyptus: not recommended for eucalyptus in landscapes because of concerns about ✔ Choose well-adapted drift, runoff into water, and toxicity to eucalyptus species. natural enemies. In comparison with these contact sprays, systemic neonic- ✔ Deep-water drought-stressed otinoid insecticides can be more effec- trees with drip hoses. Avoid tive and provide longer-lasting control, sprinkler irrigation. although they can take several weeks after application before they become ✔ If pruning is necessary, prune effective. in December or January to avoid borer attacks to freshly Eucalyptus trees are often very large cut limbs. and diffi cult to treat in landscapes. ✔ Many eucalyptus trees are stressed Don’t fertilize trees. from other problems, and tree stress Fertilizing increases damage can reduce pesticide effectiveness as from psyllids, weakening trees. well as increase a tree’s sensitivity to ✔ Use pesticides rarely and damage by the pesticide (called phy- always as a last resort. Most totoxicity). If insect damage cannot tortoise beetle infestations be tolerated and pesticides must be do not require pesticide applied, make sure trees are receiving treatments, and pesticides good cultural care before making a disrupt biological control of pesticide application. other pests. Systemic Insecticides. These insecti- cides are absorbed by plants (such as through roots) and move to the plant parts where pests feed. The systemic insecticide imidacloprid is avail- able to both professional applicators dacloprid application may contribute rainfall, or follow the application with (Imicide, Merit) and home gardeners to outbreaks of spider mites and other irrigation. Effi cacy is delayed until (Bayer Advanced 12-month Tree & pests. sometime after application. Shrub Insect Control). Soil applica- tions and tree injections (if labeled for When using systemic insecticides, Because pesticide recommendations, these methods of application) mini- whenever possible consider making registrations, labels, and products mize environmental contamination. a soil application instead of spray- change regularly, check current prod- The home-use product is relatively ing foliage or injecting or implanting uct labels or contact the University easy to apply to soil; it is measured trees. Injecting or implanting trunks of California Cooperative Extension into a bucket, diluted with water, or roots injures trees, and it is diffi cult in your county for the most current and poured onto soil near trunks, as to repeatedly place insecticide at the recommendations on the use of insec- directed on the label. proper depth. Especially avoid meth- ticides. ods that cause large wounds, such as Limit any treatments to situations implants placed in holes drilled in where damage is intolerable or pests trunks. Do not implant or inject roots threaten tree survival. Most pesticides or trunks more than once a year. are at least somewhat harmful to benefi cial predators or parasites. Imi- Based on use against other pests, the dacloprid applied to fl owering plants most effective time to apply imida- or the soil beneath them may move to cloprid on or into soil beneath trees is nectar and poison the nectar-feeding late winter to early spring, just before adult parasites, which during their or soon after new leaves emerge and larval stage partially or completely before the end of California’s rainy control other pests. Be aware that imi- season. Make an application before

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REFERENCES Available online, http://acwm.co.la. Paine, T. D., and S. H. Dreistadt. 2007. Bethke, J. A. 2007. Chrysophtharta con- ca.us/pdf/AustralianTortoiseBeetle Pest Notes: Psyllids. Oakland: Univ. trol. CAPCA Advisor. June 2007. Vol. X eng_pdf.pdf Calif. Nat. Res. Publ. 7423. (3): 20, 53. Hanks, L. M., T. D. Paine, J. G. Millar, Paine, T. D., J. G. Millar, and S. H. Bethke, J. A. 2007. Minimizing damage and J. L. Hom. 1995. Variation among Dreistadt. 2000. Pest Notes: Eucalyp- to fresh cut eucalyptus. CORF News. Eucalyptus species in resistance to tus Longhorned Borers. Oakland: Univ. Summer 2007. Vol. 11(1): 7. Eucalyptus longhorned borer in south- Calif. Nat. Res. Publ. 7425. ern California. Entomologia Experimen- Brennan, E. B., G. F. Hrusa, S. A. Wein- talis et Applicata 74: 185-194. von Ellenrieder, N. 2003. Eucalyptus baum, and W. Levison. 2001. Resis- leaf beetle (Chrysophtharta m-fuscum). tance of Eucalyptus species to Glycaspis Paine, T. D., D. L. Dahlsten, J. G. Millar, Arcadia, Calif.: Los Angeles County brimblecombei (Homoptera: Psyllidae) M. S. Hoddle, and L. M. Hanks. 2000. Department of Agriculture. Avail- in the San Francisco Bay Area. Pan- UC scientists apply IPM techniques to able online, http://www.cdfa.ca.gov/ Pacific Entomologist 77: 249-253. new eucalyptus pests. Calif. Agric. 54 phpps/ppd/PDF/Chrysophtharta_m- (6): 8-13. fuscum.pdf ❖ Garrison, R. W. 1998. New Agricul- tural Pest for Southern California: Paine, T. D., S. H. Dreistadt, R. W. Gar- Australian Tortoise Beetle, Trachymela rison, and R. Gill. 2006. Pest Notes: sloanei. El Monte, CA: Los Angeles Eucalyptus Redgum Lerp Psyllid. Oak- County Department of Agriculture. land: Univ. Calif. Nat. Res. Publ. 7460.

For more information contact the University of California Cooperative Extension in your county. See your telephone directory for addresses and phone numbers.

AUTHORS: J. G. Millar, Entomology, UC Riverside; T. D. Paine, Entomology, UC Riv- erside; J. A. Bethke, UC Cooperative Exten- sion, San Diego Co.; R. W. Garrison, Calif. Dept. of Food & Agric.; K. A. Campbell, En- tomology, UC Riverside; and S. H. Dreistadt, UC Statewide IPM Program, Davis TECHNICAL EDITOR: M. L. Flint COORDINATION AND PRODUCTION: P. N. Galin and M. L. Fayard ILLUSTRATIONS: S. H. Dreistadt; Fig. 1: WARNING ON THE USE OF CHEMICALS Fig. 2: R. W. Garrison 1998; Table 1: Pesticides are poisonous. Always read and carefully follow all precautions and safety recommendations Adapted partly from Brennan et al. 2001 and given on the container label. Store all chemicals in the original labeled containers in a locked cabinet or shed, Hanks et al. 1995. away from food or feeds, and out of the reach of children, unauthorized persons, pets, and livestock. Pesticides applied in your home and landscape can move and contaminate creeks, rivers, and oceans. Produced by UC Statewide IPM Program, Confine chemicals to the property being treated. Avoid drift onto neighboring properties, especially gardens University of California, Davis, CA 95616 containing fruits or vegetables ready to be picked. Do not place containers containing pesticide in the trash or pour pesticides down sink or toilet. Either use This Pest Note is available on the the pesticide according to the label or take unwanted pesticides to a Household Hazardous Waste Collection site. Contact your county agricultural commissioner for additional information on safe container disposal and World Wide Web (www.ipm.ucdavis.edu) for the location of the Household Hazardous Waste Collection site nearest you. Dispose of empty containers by following label directions. Never reuse or burn the containers or dispose of them in such a manner that they may contaminate water supplies or natural waterways.

The University of California prohibits discrimination or harassment of any person on the basis of race, color, national origin, religion, sex, gender identity, pregnancy (including childbirth, and medical conditions related to pregnancy or childbirth), physical or mental disability, medical condition This publication has been anonymously peer (cancer-related or genetic characteristics), ancestry, marital status, age, sexual orientation, citizen- reviewed for technical accuracy by University of ship, or service in the uniformed services (as defined by the Uniformed Services Employment and California scientists and other qualified profession- Reemployment Rights Act of 1994: service in the uniformed services includes membership, applica- als. This review process was managed by the ANR tion for membership, performance of service, application for service, or obligation for service in the Associate Editor for Urban Pest Management. uniformed services) in any of its programs or activities. University policy also prohibits reprisal or To simplify information, trade names of products retaliation against any person in any of its programs or activities for making a complaint of discrimi- have been used. No endorsement of named products nation or sexual harassment or for using or participating in the investigation or resolution process of is intended, nor is criticism implied of similar products any such complaint. University policy is intended to be consistent with the provisions of applicable that are not mentioned. State and Federal laws. Inquiries regarding the University’s nondiscrimination policies may be This material is partially based upon work supported directed to the Affirmative Action/Equal Opportunity Director, University of California, Agriculture and by the Extension Service, U.S. Department of Natural Resources, 1111 Franklin Street, 6th Floor, Oakland, CA 94607, (510) 987-0096. Agriculture, under special project Section 3(d),

◆ 5 of 5 ◆ Leaf beetles - Chrysomelidae LB-03-02 Australian tortoise beetle Rating: C (Trachymela sloanei)

‰ Native to Australia, now widespread in S CA. ‰ Hosts: Red gum eucalyptus (Eucalyptus camaldulensis); Blue gum eucalyptus (E. globulus); and Rose gum eucalyptus (E. grandis). ‰ Field ID: Adults about 6-7 mm long, brown with darker mottled spots, hemispherical and flattened underneath. Legs with tarsomeres bilobed and covered ventrally with a thick set of bristles. Larvae brown, caterpillar-like, with black head and three small pairs of legs on thorax, and sclerotized tubercles along the body. Elliptical, orange eggs are laid in crevices or fissures in or under bark. Both adults and larvae feed on foliage during the night. adult Life size

adult on ground bilobed tarsus larva

Damage on E. camaldulensis eggs

Los Angeles County Agricultural Commissioner's Office/Weights and Measures Department – Prepared by N. von Ellenrieder, September 2003