New pests and diseases t Light brown apple ’s arrival in worries commodity groups

by Lucia G. Varela, Marshall W. Johnson, Larry Strand, Cheryl A. Wilen and Carolyn Pickel

Light brown apple moth is an exotic pest that was confirmed in California in March 2007. It is a tortricid leaf- roller moth native to , which has a broad range of plant hosts with the capacity to cause damage across a wide array of crops, natural areas and ornamental plants. California and federal agencies have issued quaran- tine orders affecting production and Natasha Wright, Florida Dept. of Agriculture and Consumer Services, Bugwood.org Agriculture and Consumer Services, of Florida Dept. Wright, Natasha retail nurseries, and potentially fruit The light brown apple moth, a tortricid leafroller, is extremely variable and and vegetable exports. It is found difficult to identify visually. The ’s reproductive organs must be examined in thus far primarily in nurseries near order to obtain a positive identification. urban areas. Eradication efforts are tions of Alameda, Contra Costa, Marin, clover, plantain and many other plants under way to prevent its spread into Monterey, , San Mateo, (Brockerhoff et al. 2002; Buchanan 1977). California crop areas and throughout Santa Clara, Santa Cruz and Solano In California, larvae identified as pos- counties are currently subject to quar- sible light brown apple moth have been the . antine (CDFA 2007d). According to cur- found in apples, strawberries and grapes rent California Department of Food and in commercial fields. The most common March 2007, the U.S. Department Agriculture (CDFA) regulations, a county hosts in nurseries and the landscape of Agriculture’s and is quarantined if specimens representing have been Prunus spp. and California PlantIN Health Inspection Service (APHIS) more than one life stage of the moth or wax myrtle (Myrica californica). However, confirmed the presence of light brown a mated female are confirmed within a an extensive survey of possible hosts apple moth (LBAM) ( postvittana) 3-mile radius (USDA APHIS 2007b). has not been conducted, so these initial in California, based on specimens from The light brown apple moth is a tor- findings may not be representative of Alameda and Contra Costa counties. As tricid leafroller moth native to Australia. the types of plants likely to be infested of December 2007, a total of 15,594 male It is now established in , in California. Light brown apple moth caught in pheromone traps had , the British Isles and is polyphagous (able to feed on many been confirmed as light brown apple (Danthanarayana 1975; Suckling plants). It may encounter and infest ad- moth. The largest numbers of moths et al. 1998). It has a broad range of plant ditional hosts with which it has not been are being trapped in southern Santa hosts, including herbaceous plants, land- previously associated. Cruz and northern Monterey counties. scape trees, ornamental shrubs, fruit California and U.S. federal agencies The second highest area of capture in- and certain vegetable crops (Rogers et have issued orders restricting intra- and cludes contiguous portions of northwest al. 2003; Wearing et al. 1991). It is known interstate shipments of plant material Alameda, western Contra Costa and to feed on 250 plant species in over 50 from quarantine counties (CDFA 2007d; San Francisco counties. Less than 1% of families, but prefers plants in the aster USDA APHIS 2007a). At present, produc- the captures are from mostly single trap (Asteraceae), legume (Fabaceae), knot- tion and retail nurseries are the indus- catches in , Marin, Napa, weed (Polygonaceae) and rose (Rosaceae) tries most affected by these regulations. San Luis Obispo, San Mateo, Santa Bar- families (CDFA 2007a). Equally important are the current or bara, Santa Clara, Solano and Sonoma Elsewhere, light brown apple moth potential trade restrictions on fruits and counties (CDFA 2007c). Although light has been reported as a pest on apple, vegetables imposed by importing coun- brown apple moth has been present in pear, peach, apricot, , persim- tries (CFIA 2007; CDFA 2007b). Hawaii since the late 1800s, this is the mon, , walnut, grape, kiwifruit, Identification and description first time this pest has been detected in strawberry, cane berries and cole crops. the continental United States. It may also infest oak, willow, poplar, Positive identification of light brown Although light brown apple moth has cottonwood, alder, pine, eucalyptus, apple moth can be made with certainty been confirmed in 14 counties, only por- rose, camellia, jasmine, , only by examining the adult moth’s re-

http://CaliforniaAgriculture.ucop.edu • April–June 2008 57 Jack Kelly Clark Kelly Jack productive organs (Dugdale et al. 2005; Zimmerman 1978). Growers who wish to obtain positive identification of a sus- pect insect should bring the live larvae, if possible still inside the webbed nest of rolled-up leaves, to their agricultural commissioner’s office. Light brown apple moth closely resembles other native California The leafroller’s mature feeds on hundreds of different plants and agricultural crops. tortricids such as orange tortrix ( franciscana) and garden A B tortrix ( peritana). Adults hold their wings over their abdomens in a bell shape when at rest, and have protrud- ing mouthparts that resemble a snout. The antennae are simple, not featherlike. Adult size may vary during the season, with larger individuals present during cool, wet months and smaller individu- als present during warm, dry months C D (Danthanarayana 1976). Wings. The length of the forewing (front wing, the most obvious wing when the moth is at rest) in the female is 0.27 to 0.5 inch (7 to 13 millime- ters) and in the male approximately 0.23 to 0.4 inch (6 to 10 millimeters) (see photos A, B). There is consider- able variation in the color patterns E Scale F of the wings, especially on the males 5mm (Bradley 1973). The basal half (closest to the head) of the male forewing may be light brown to pale yellow, while the distal half (farthest from the head) is reddish-brown (see photos B, C). In deeply colored forms the distal half of the forewing may vary from reddish- brown (see photo C) to blackish with G H purplish mottling (see photo B), and the basal half is sparsely speckled with black. In some males, the two-tone wing coloration of the forewings may be absent. Instead they are light brown with a slightly darker oblique mark- ing (see photos D, E, F, G, H). While all

A, B, by David Williams, State of Victoria Department of Primary Industries; C, D, F, G, I, J by Jack Kelly Clark; E, H by Brad Oliver, Monterey County Agricultural Commissioner’s office Agricultural Commissioner’s Monterey County H by Brad Oliver, E, Clark; Kelly J by Jack I, G, F, D, C, Department of Primary Industries; Victoria State of Williams, by David B, A, color patterns of the wing have been found in males caught in California, by I J far the most prevalent pattern has been light brown with slightly darker oblique marking (see photos D, E, F, G, H). In the female, forewing color var- ies from uniform light brown, with almost no distinguishing markings or with a dark spot in the center-front of the folded wings, to the typical oblique Female (A) and male (B) light brown apple moths. The wing-color pattern of markings of the male, but with less light brown apple moth males (C–I) in pheromone traps can be highly variable. contrast between the basal and distal Males have a costal fold (arrow) on the forewing (J). halves (see photo A). The hindwings

58 CALIFORNIA AGRICULTURE • VOLUME 62, NUMBER 2 HortResearch, New Zealand HortResearch, (back wing) of both sexes are pale mine if the specimens are possibly light brown to grey, either uniform in color brown apple moth. However, absolute or mottled with wavy dark-brown certainty is not possible because there markings (see photo I). are still many California tortricid lar- Males have an extension of the “for- vae whose morphological characters or ward” outer edge of the forewing called DNA have not been studied. the costal fold (see photo J), which runs Pupae. The pupa is found in a thin- from the base of the wing to two-fifths walled silken cocoon, often between of the length of the wing edge. This is an two leaves webbed together. It turns expanded part of the wing that folds up from green to brown as it matures and over the front edge of the wing as a flap. is dark reddish-brown and 0.4 to 0.6 Females do not have this costal fold. inch (10 to 15 millimeters) long. Pupae Eggs of the light brown apple moth are Eggs. The eggs are pale yellow to of all tortricids are very similar in ap- typically deposited on the upper surface of light green, broadly oval and flat with a pearance (Danthanarayana 1975). host leaves in masses of 20 to 50. pebbled surface. They are laid slightly Life cycle of a pest overlapping each other like fish scales. The egg mass is covered with a green- Light brown apple moth is found in slow larval development considerably ish transparent coating. An egg mass southeastern Australia; it was intro- (Geier and Briese 1980). Thus, the pest may contain from 2 to 170 eggs, but duced on the western coast, but does overwinters as second to fourth instar typically has 20 to 50 eggs. A female not survive well at high temperatures larvae that feed on herbaceous plants, may lay multiple egg masses, deposit- and is a more serious pest in cooler buds of deciduous trees or shrubs, ing them on the upper surface of host areas with mild summers (Geier mummified fruit and other plant mate- leaves and occasionally on fruit and and Springett 1976; Buchanan 1977; rial. Larvae may survive for up to young stems. As the eggs develop, Danthanarayana et al. 1995). The pest 2 months in the winter without feeding. they change to paler yellow-green. performs best under cool conditions Adult moths emerge after 1 to Immediately prior to hatching, the dark (mean annual temperature of approxi- 3 weeks of pupation and mate soon head of the developing caterpillar is mately 56°F) with moderate rainfall after emergence. They stay sheltered in visible (Danthanarayana 1983). (approximately 29 inches annually) and the foliage during the day, resting on Larvae. The newly hatched larva is moderate-high relative humidity (ap- leaf undersides. Moths fly 2 to 3 hours pale yellow-green, 0.06 to 0.08 inch proximately 70%). Hot, dry conditions after sunset and before daybreak. The (1.5 to 2 millimeters) long and has a may reduce populations significantly, light brown apple moth is capable of dark brown head. There are five to six and it is unknown whether the insect flying only short distances to find a larval instars (stages). Mature larvae will be able to establish in locations suitable plant host (Suckling et al. 1994). range from 0.4 to 0.7 inch (10 to 18 milli- such as the Central Valley and inland Most moths fly no farther than 330 feet meters). The head is light yellow-brown deserts of California. (100 meters), but some may fly as far as and the prothoracic shield (segment A degree-day model (which predicts 2,000 feet (600 meters). Males disperse behind the head) is light greenish- the moth’s growth and development farther than females. Adults are less brown with no dark markings. The according to mean temperatures over likely to leave areas with high-quality body is medium green with a darker time) indicates that there would most hosts. Adult life span is 2 to 3 weeks, green central stripe that may continue likely be two generations a year in with longevity influenced by host plant to the prothoracic shield; larvae may California’s Central and North Coast and temperature. also have darker longitudinal stripes areas, and three or four generations a Females begin to lay eggs 2 to 3 days If light brown apple moth is found in fruit-production after emerging, depositing eggs at night. They prefer to deposit their eggs on counties, the inability to export fruit to some countries smooth leaf surfaces, and usually lay a may cause severe economic hardship. total of 120 to 500 eggs, but can lay up to 1,500 eggs (Danthanarayana 1975). An on both sides. The hairs on the body are year in the Central Valley and Southern egg takes from 5 to more than 30 days to whitish. The thoracic legs are the same California. The lower and upper devel- hatch, depending on temperature. color as the head, but paler, and are opmental thresholds for light brown ap- Larvae emerge from eggs after 1 to also unmarked. Larvae have a greenish ple moth are 45°F and 88°F, respectively 2 weeks. Although egg masses may in- anal comb with seven teeth — a comb- (Danthanarayana 1975). Completion of clude 20 to 50 eggs, the resulting larvae shaped structure at the tail end of the the entire life cycle requires 620 degree- disperse widely, each creating a nest larva. An overwintering larva may have days above 45°F. In Australia, New on a separate leaf. When a larva finds a darker head and prothoracic shield Zealand and the British Isles, genera- a feeding site, it forms a silken shelter (Danthanarayana 1975, 1983). Larvae tions overlap. Light brown apple moth near the midrib on the leaf underside can be screened using morphological does not have a winter resting stage and begins to feed. Second and later characters and DNA analysis to deter- (diapause). Cold winter temperatures stages feed on two to several leaves

http://CaliforniaAgriculture.ucop.edu • April–June 2008 59 Apple Apple leaf

inadvertently moved during the trans- port of nursery stock. Currently the brunt of the economic cost is borne by the nursery industry in the most in-

Photos: HortResearch, New Zealand HortResearch, Photos: fested counties. If light brown apple moth contin- ues to spread, several vegetable and fruit crops may be affected such as apples, pears, caneberries and pep- pers. California growers already deal with one or more leafroller pest species on most of these crops. Management practices are available for suppressing leafrollers, and the same approaches would be used against light brown apple moth. However, the primary concern is the trade restrictions im- posed by importing countries. Mexico and Canada already have restrictions on the importation of crops and plants Originally from southern Australia, the light brown apple moth can feed on and damage a broad range of crops such as, above, apple. If the pest becomes established in California from the infested areas of California. the most important impact to growers will likely be trade restrictions on crop exports. China has begun the information gath- ering that frequently leads to trade webbed together, a leaf webbed to a interior of a pome fruit through the ca- restrictions. Many countries such as fruit, or in the center of a fruit cluster. lyx. They can cause internal damage to Chile, Korea, Peru and South Africa The larvae feed within these shelters, stone fruits as well. list light brown apple moth as a quar- and they may feed on fruit when it Minor feeding damage can take antine pest and may require certifica- touches a leaf. Larvae on fruit are most the form of pinpricks, or “stings,” on tion attesting that commodities such as likely to be found near the calyx, the the fruit surface. In grapes, larvae pome fruits, grapes, citrus and stone residual basal flower parts. When dis- can cause extensive loss of flowers or fruits are pest-free. If light brown ap- turbed they wiggle violently, suspend newly set berries in the spring. Later ple moth is found in fruit-production themselves from a silken thread and in the season, grapes can be severely counties, the inability to export fruit drop to the ground, where they feed on damaged by larvae feeding among to some countries may cause severe groundcover hosts. Larval development the berries, allowing plant pathogens economic hardship to some sectors of can take from 3 to 8 weeks, depending causing mold to enter (Buchanan 1977; California’s agricultural industry. on temperature. Pupation is completed Buchanan et al. 1991; Lo and Murrell APHIS has called together experts inside the silken feeding shelter. The 2000). In citrus, larval feeding causes from the United States, Australia and pupal stage lasts 1 to 3 weeks. fruit drop or halo scars around the New Zealand to form a Technical stem end of the fruit. In crops such as Working Group to advise on steps for Potential crop damage kiwifruit, plum, citrus and pome fruit, managing the light brown apple moth Like other tortricid leafrollers, light the maturing fruit produces a layer of infestation in California. APHIS and brown apple moth feeds from within corky tissue over the leafroller dam- CDFA’s current long-term goal is to the sheltering nest it constructs. Light age. Buds of deciduous host plants are eradicate light brown apple moth from brown apple moth has attained pest vulnerable to attack in the winter and California (see page 55). However, no status only in southeastern Australia early spring. Conifers are damaged single control technique currently ex- and New Zealand (Danthanarayana by larval activity such as needle ty- ists that can be effectively implemented 1995). Foliar feeding is usually con- ing, chewing of buds and boring into over an entire infested area. Eradication sidered minor in fruit crops, though it stems. In tree nurseries, damage to ter- will require a multiphase approach. might be of economic importance on minal buds on seedlings and saplings Eradication will focus initially on nursery stock and of cosmetic impor- can cause multiple or crooked leaders specific localities to determine its fea- tance on landscape ornamentals. On (Wearing et al. 1991). sibility. While eradication attempts are fruit crops the primary concern is fruit under way, it is important to ensure California impacts and control damage (Wearing et al. 1991; Lo et al. that light brown apple moth infesta- 2000). Larvae remove the outermost In California, light brown apple tions do not continue to increase in layers of the fruit surface as they feed. moth has been detected on agricul- size and expand to uninfested areas. Superficial feeding injury to the fruit tural lands mostly in production and Environmentally compatible methods is typically caused by later immature retail nurseries located near urban of pest management are needed to stages. Young larvae may enter the areas. Light brown apple moth may be maintain public support for the eradi-

60 CALIFORNIA AGRICULTURE • VOLUME 62, NUMBER 2 cation effort and to keep light brown and species) and preda- as other important agricultural states apple moth at low numbers across agri- tors (such as spiders, minute pirate (such as Arizona, Texas and Florida). cultural, urban and natural areas. bugs, lacewings and Phytocoris bugs). Although eradication from its present Several reduced-risk insecticides It is highly probable that some of the California distribution may seem dif- are registered in agricultural and or- California native natural enemies will ficult and expensive, the effort is worth- namental crops that effectively control expand their prey ranges to include while given the possible economic and leafrollers. These include insect growth light brown apple moth eggs, larvae ecological ramifications should the regulators, spinosyns and Bacillus thur- and pupae. Natural enemies could also species establish itself and prolifer- ingiensis (Bailey et al. 1996) be collected in the native home of light ate throughout agricultural acreage in In Australia, light brown apple brown apple moth and introduced into California and the United States. moth has been managed in citrus, California. In Australia, as many as grapes and other crop systems using 25 different species have L.G. Varela is Integrated Pest Management (IPM) (Mo et al. 2006). been reared from light brown apple Advisor, UC Statewide IPM Program and UC Light brown apple moth pheromone moths collected in the field (Charles et Cooperative Extension (UCCE), Sonoma County; has two key components, both of al. 1996; Geier and Briese 1980; Paull M.W. Johnson is UCCE Specialist and Entomolo- which must be present for optimal and Austin 2006). Imported natural en- gist, Department of Entomology, UC Riverside; control (Bellas et al. 1983; Suckling and emies require extensive host specificity L. Strand is Principal Editor, UC Statewide IPM Clearwater 1990). Presently, mating testing, which may take several years Program; C.A. Wilen is IPM Advisor, UC Statewide disruption is being implemented in to ensure that they are not a threat to IPM Program and UCCE, San Diego County; and C. Pickel is IPM Advisor, UC Statewide Program some infested areas of California. endangered endemic species. and UCCE, Sutter/Yuba Counties. The authors There are numerous leafroller spe- Currently, light brown apple moth thank Marc Epstein, CDFA Plant Pest Diagnostics, cies in California, and many of these is found in limited areas of California. Sacramento; Phillip Holmes, USDA/APHIS/PPQ have effective (such as However, it has the potential to es- Watsonville LBAM Project; and Joyce Strand, UC Cotesia, Exochus, Macrocentrus, Nemorilla tablish widely in California as well Statewide IPM Program.

to prevent the entry of Epiphyas postvittana (Walker) Mo J, Glover M, Munro S, Beattie GAC. 2006. References (light brown apple moth). www.inspection.gc.ca/eng- Evaluation of mating disruption for control of lightbrown Bailey P, Baker G, Caon G. 1996. Field efficacy lish/plaveg/protect/dir/d-07-03e.shtml#12c. apple moth (: ) in citrus. J Econ and persistence of var. kurstaki Charles JG, Walker JTS, White V. 1996. Leafroller Entomol 99:421–6. against Epiphyas postvittana (Walker) (Lepidoptera: phenology and parasitism in Hawkes Bay, New Zealand, Paull C, Austin AD. 2006. The hymenopteran para- Tortricidae) in relation to larval behaviour on grape- canefruit gardens. NZ J Crop Hort Sci 24:123–31. sitoids of light brown apple moth, Epiphyas postvittana vine leaves. Aust J Entomol 35:297–302. Danthanarayana W. 1975. The bionomics, distribu- (Walker) (Lepidoptera: Tortricidae) in Australia. Aust J Bellas TE, Bartell RJ, Hill A. 1983. Identification of tion and host range of the light brown apple moth, Entomol 45:142–56. two components of the sex pheromone of the moth, Epiphyas postvittana (Walk.) (Tortricidae). Aust J Zool Rogers DJ, Walker JTS, Moen IC, et al. 2003. Under- Epiphyas postvittana (Lepidoptera, Tortricidae). J 23:419–37. storey influence on leafroller populations in Hawke’s Bay Chem Ecol 9:503–12. Danthanarayana W. 1976. Environmentally cued organic apple orchards. NZ Plant Protect 56:168–73. Bradley JD. 1973. Epiphyas postvittana (Walker). size variation in the light-brown apple moth, Epiphyas Suckling DM, Brunner JF, Burnip GM, Walker JTS. In: British Tortricoid Moths. Cochylidae and Torticidae: postvittana (Walk.) (Tortricidae), and its adaptive value in 1994. Dispersal of Epiphyas postvittana (Walker) and Tortricinae. Ray Society, London. p 126–7. dispersal. Oecologia 26:121–32. Planotortrix octo Dugdale (Lepidoptera: Tortricidae) at Brockerhoff EG, Jactel H, Leckie AC, Suckling DM. Danthanarayana W. 1983. Population ecology of a Canterbury, New Zealand orchard. NZ J Crop Hort Sci 2002. Species composition and abundance of leafrol- the light brown apple moth, Epiphyas postvittana (Lepi- 22:225–34. lers in a Canterbury pine plantation. NZ Plant Protect doptera: Tortricidae). J Anim Ecol 52:1–33. Suckling DM, Burnip GM, Walker JTS, et al. 1998. 55:85–9. Danthanarayana W, Gu H, Ashley H. 1995. Popula- Abundance of leafrollers and their parasitoids on Buchanan GA. 1977. The seasonal abundance tion growth potential of Epiphyas postvittana, the light- selected host plants in New Zealand. NZ J Crop Hort Sci and control of light brown apple moth, Epiphyas post- brown apple moth (Lepidoptera: Tortricidae) in relation 26:193–203. vittana (Walker) (Lepidoptera: Tortricidae), on grape- to diet, temperature and climate. Aust J Zool 43:381–94. Suckling DM, Clearwater JR. 1990. Small scale vines in Victoria. Aust J Ag Res 28:125–32. Dugdale JS, Gleeson D, Clunie LH, Holder PW. trials of mating disruption of Epiphyas postvittana (Lepi- Buchanan GA, Stirrat SC, Madge DG. 1991. 2005. A diagnostic guide to Tortricidae encountered in doptera: Tortricidae). Environ Entomol 19:1702–9. Integrated control of light brown apple moth, Epi- field surveys and quarantine inspections in New Zea- [USDA APHIS] US Department of Agriculture phyas postvittana (Walker), in vineyards. Wine Ind J land: Morphological and molecular characters. Ministry 6:220–2. Animal and Plant Health Inspection Service. 2007a. of Agriculture and Forestry, Wellington. 161 p. Federal domestic quarantine order Epiphyas postvit- [CDFA] California Department of Food and Ag- Geier PW, Briese DT. 1980. The light-brown apple tana (light brown apple moth) DA-2007-42. riculture. 2007a. Light brown apple moth host list. moth, Epiphyas postvittana (Walker): 4. Studies on www.aphis.usda.gov/plant_health/plant_pest_info/ www.cdfa.ca.gov/phpps/PDEP/target_pest_disease_ population dynamics and injuriousness to apples in the lba_moth/downloads/federalorder-11-20-07.pdf. 5 p. profiles/LBAM_HostList.pdf. 6 p. Australian Capital Territory. Aust J Ecol 5:63–93. USDA APHIS. 2007b. Light Brown Apple Moth CDFA. 2007b. Light brown apple moth project: Geier PW, Springett PB. 1976. Population charac- (LBAM) Regulatory Protocol. APHIS Plant Protection and Advisories. PSA No. 12-2007. www.cdfa.ca.gov/ teristics of Australian leafrollers (Epiphyas spp., Lepi- Quarantine. www.aphis.usda.gov/plant_health/plant_ phpps/pdep/lbam/advisories.html. 4 p. doptera) infesting orchards. Aust J Ecol 1:129–44. pest_info/lba_moth/downloads/lbam-regulatoryprotocol. CDFA. 2007c. Light brown apple moth situation Lo PL, Murrell VC. 2000. Time of leafroller infesta- pdf. 2 p. reports. www.cdfa.ca.gov/phpps/PDEP/lbam/situation- tion and effect on yield in grapes. NZ Plant Protect Wearing CH, Thomas WP, Dugdale JS, Dan- reports.html. 4 p. 53:173–8. thanarayana W. 1991. Tortricid pests of pome and stone- CDFA. 2007d. Plant Quarantine Manual: Light Lo PL, Suckling DM, Bradley SJ, et al. 2000. Factors fruits, Australian and New Zealand species. In: Tortricid Brown Apple Moth State Interior Quarantine. http:// affecting feeding site preferences of light brown apple Pests: Their Biology, Natural Enemies, and Control. World pi.cdfa.ca.gov/pqm/manual/pdf/419.pdf. 19 p. moth, Epiphyas postvittana (Lepidoptera: Tortricidae), Crop Pests, Vol. 5. Elsevier: Amsterdam. p 453–72. [CFIA] Canadian Food Inspection Agency. 2007. on apple trees in New Zealand. NZ J Crop Hort Sci Zimmerman EC. 1978. of Hawaii: Micro- Plant protection (phytosanitary) import requirements 28:235–43. lepidoptera. Honolulu: Univ Pr Hawaii. 1,923 p.

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