Light brown apple moth

Light brown apple moth
File:LBAM.jpg
Epiphyas postvittana (male left, female right)
Scientific classification
Kingdom:	Animalia
Phylum:	Arthropoda
Class:	Insecta
Order:	Lepidoptera
Suborder:	Ditrysia
Superfamily:	Tortricoidea
Family:	Tortricidae
Genus:	Epiphyas
Species:	E. postvittana
Binomial name
Epiphyas postvittana Walker, 1863

The Light brown apple moth (Epiphyas postvittana) (often abbreviated to LBAM) is a leafroller moth belonging to the lepidopteran family Tortricidae.

Identification

Adult moths

Light brown apple moth adults are variable in colour and may be confused with other leafroller moths and similar species. Typical males have a forewing length of 6–10 mm with a light brown area at the base, which is distinguishable from a much darker, red-brown area at the tip. The latter may be absent, with the moth appearing uniformly light brown, as in the females, who have only slightly darker oblique markings distinguishing the area at the tip of the wing. Females have a forewing length of 7–13 mm.

Larvae

Larvae are not easily distinguished from the larvae of other tortricid leafrollers. The first larval instar has a dark brown head; all other instars have a light fawn head and prothoracic plate. Overwintering larvae are darker. First instar larvae are approximately 1.6 mm long, and final instar larvae range from 10–18 mm in length. The body of a mature larva is medium green with a darker green central stripe and two side stripes.

Distribution

The light brown apple moth is a native insect of Australia. It has been introduced and now occurs in New Caledonia, the British Isles, Hawaii, Western Australia and New Zealand. In 2007 the moth was found in mainland United States, principally along the West Coast. Quarantine measures and aerial spraying were imposed to help contain its spread.[1]

Life cycle

Light brown apple moth pass through three generations annually with a partial fourth generation in some years. The moth has no winter resting stage. There is considerable overlap in the generations. In warmer areas, four or even five[2] generations are completed annually, with major flight periods occurring during September-October, December-January, February–March, and April–May. In cooler climates, the number of complete generations may be reduced to two.

E. postvittana 5th instar larva

Eggs are laid in clusters of 3–150 on leaves or fruit. A single female might lay hundreds of eggs.[3] Adults produced by the overwintering larval generation emerge during October and November. These give rise to the first summer generation, in which final instar larvae mature between January and mid February. Second generation larvae reach maturity during March and April, and the adults from this generation provide third generation eggs. Normally, the rate of larval development is slowed considerably during the winter, particularly when temperatures approach freezing; thus the majority of larvae over-winter in the prolonged early juvenile phases of the second third, and fourth instars. During this period they normally feed on herbaceous plants. Re-invasion of apple trees takes place during October-December, when moths of the third generation start laying eggs again on apple leaves.

Sex pheromone

Females release a specific blend of sex pheromone to attract males. The blend is a mixture of two compounds (E)-11-tetradedecen-1-yl acetate, comprising 95% of the mixture and (E,E)-9,11-tetradecadien-1-yl acetate comprising the remaining 5% . As an attractant used in moth traps, the synthetic versions of these pheromones are highly specific. Only very closely related species of moths are attracted to the pheromone's scent.[4]

Diet and damage

The insect is highly polyphagous and the larvae attack numerous horticultural crops in Australia and New Zealand. It is known to feed on 123 dicotyledonous plant species, including 22 Australian natives, belonging to 55 different families. In New Zealand, over 250 host species have been recorded. It attacks nearly all types of fruit crops, ornamentals, vegetables, glasshouse crops, and occasionally young pine seedlings .

The larvae cause significant damage to foliage and fruit . Early instars feed on tissue beneath the upper epidermis (surface layer) of leaves, while protected under self-constructed silken webs on the undersurface of leaves. Larger larvae migrate from these positions to construct feeding niches between adjacent leaves, between a leaf and a fruit, in the developing bud, or on a single leaf, where the leaf roll develops. The late stage larvae feed on all leaf tissue except main veins.

Superficial fruit damage is common in apple varieties which form compact fruit clusters, though more significant damage may also occur such that crops are no longer commercially viable. Leaves are webbed to the fruit and feeding injury takes place under the protection of the leaf; or larvae spin up between fruits of a cluster. Internal damage to apple, pear, and citrus fruits is less common, but a young larva may enter the interior of an apple or pear fruit through the calyx or beneath the stem of a citrus fruit. Excreta are usually ejected on to the outside of the fruit.

Control

The species has been classified as a noxious insect in the United States and Canada, leading to restrictions on produce from counties with substantial populations. Typical orchard control of the insect commonly involves IPM regimes using a variety of methods such as insecticide applications, biological control and occasionally mating disruption, which typically involves releasing synthetic insect phermones to confuse the male moth's tracking of female scent. This results in fewer pairings and thus fewer offspring. Sex pheromone lures are also often used to assess and monitor populations of moths in specific areas.

Eradication measures in Australia and New Zealand

The moth is endemic to Australia[5] where various measures, including using pheromones to disrupt mating, have been taken for more than a decade.[6]

Eradication measures in California

Though the first LBAM confirmed in California by DNA analysis was found in February 2007, UC Davis invasion biology experts say that because it is so widespread, from Los Angeles to north of San Francisco, LBAM has likely lived in California for years and possibly decades.

Following the DNA confirmation of LBAM, officials initiated an emergency control program, including domestic and international quarantines and inspection programs. In 2007 and 2008, an aerial eradication program, involving the dissemination (aerial spraying) of E. postvittana sex pheromone over sixty square miles near the Pacific coast between Monterey and Santa Cruz was begun.[7] It is expected to continue for five years.

Helping Our Peninsula's Environment, opponents of the spraying, concerned over the potential impacts to humans and our environment, obtained a court injunction in October 2007 that postponed the pheromone pesticide spraying for two weeks. The injunction was lifted because it was impossible to prove that "inert" ingredients cause harm when the manufacturer and the government agencies refused to disclose the names and concentrations of the ingredients.

After the spraying in Monterey and Santa Cruz counties last fall, the California Department of Food and Agriculture received 330 reports (including incomplete reports) of noise or adverse health effects similar to the symptoms such as eye irritation, coughing, wheezing, and muscle aches. A local environmental group also reported that they received more than 300 complaints.

Critics state that no published efficacy reports on the pesticide formulations used aerially against LBAM exist[8], raising questions about the validity of the eradication effort.

Some critics believe that the products used for the aerial spray, Checkmate OLR-F and Checkmate LBAM-F, contain polypropylene polybenzyl isocyanate, or PPI. PPI is an isocyanate which is listed as a "hazardous agent" by the National Institutes of Health because it irritates skin and breathing passages at high concentrations.[9] The EPA, which knows the full, confidential formula, claims that PPI is not used, but the manufacturer's refusal to publish the trade secret formulation has led many critics to believe that the EPA is lying.[10]

Helping Our Peninsula's Environment proposes controlling the moth with targeted pheromone-baited sticky traps. These are the same traps used for population measuring purposes to catch. They have caught and killed almost all the 16,500 LBAM moths found so far in California.[11] This would employ four additional traps for every LBAM caught.

Other critics of the aerial spray plan, such as The California Nevada Regional Conservation Committee of the Sierra Club[12], propose that twist ties be impregnated with the pheromone and hung on trees and other structures across the area. They say they prefer least-toxic, environmentally sensitive control methods to spraying.[13] The California Department of Food and Agriculture has determined that more than nine million twist ties would be required to cover the infested area. Because the twist ties need to be placed at optimal distances from each other, one trained employee can correctly place 30 to 40 twist ties in a single day.[14] Twist ties become ineffective after about three months and then need to be removed, disposed of, and replaced four times a year. As a result, using twist ties as the primary measure to control the moth has been ruled out.[15] In early February of 2008, the California Department of Food and Agriculture and the U.S. Department of Agriculture (USDA) announced that treatment using pheromone-infused twist ties was scheduled for LBAM eradication in some lightly infested areas. A USDA official has stated that they are still considering whether to treat San Francisco and the East Bay Area through ground or aerial application.[16]

Several city councils passed or considered resolutions against the spraying, and more lawsuits were filed.[17] In February 2008, several legislative bills based on citizen concerns about aerial spraying in urban areas and the ability of state agencies to declare a state of emergency were drafted by state legislators.[18], [19]

In order to conduct the spraying, the U.S. Department of Agriculture (not the state agency) was able to obtain an "emergency exemption from registration" from the U.S. EPA. Representatives of the California Department of Pesticide Regulation say that because of that exemption, the spraying program is not subject to state approval.[20]

External links

• EPA Quarantine Exemptions for Light Brown Apple Moth Pheromones
• EPA Lepidopteran Pheromones Fact Sheet

Spray Opponent Links

• Helping Our Peninsula's Environment - the organization which filed the first lawsuit and stopped the spraying for two weeks (www.1hope.org/checkmate)
• LBAMSPRAY - Defending the Central Coast against the Aerial BioChemical Pesticide Spray
• Stop the Spray
• East Bay Pesticide Alert
• California Alliance to Stop the Spray
• Hope For Truth