Gypsy Moth in B C A Case Study

Gypsy Moth in B. C. A Case Study in Urban Entomology Tim Ebata, MSc, RPF Forest Practices Branch, BCMOF

Biology § Egg masses laid in late summer; hairs from female protect § Hatching of eggs usually in early May § 1 st instars disperse by ballooning § Caterpillars go through 5 to 6 instars § Pupate in mid-summer § Adults emerge in late summer, females have wings but are flightless

Biology

History in North America § Originally from Europe (also Asian) § Imported to Medford, Mass. By Leopold Trouvelot in 1869 § wanted to “cross” native moths to produce a silk worm industry § Cages blew over, the rest was history § First outbreak recorded in 1890 attempts to eradicate failed § By 1994, spread throughout E. NA but not in the West.

History in B. C. § 1911 - First reported on plants imported from Europe (destroyed on dock) § 1978 - Kitsilano infestation - canoe from Quebec, eradicated with Carbaryl § Since then >120 different locations where GM have been found, some required eradication, most died out on own § Complete history on Gypsy Moth web site

Damage § Feeds on over 300 different shrub and tree species § Each caterpillar can eat up to 100 cm 2 of foliage (two leaves per day for a late instar larva) § Outbreaks in hardwood forests in the east are very dramatic

Damage

Damage § Human Health § Masses of larvae covering everything § Hairs are “urticating” allergies

Damage cont’d § In BC, threat is not to commercial forest even though conifers can be consumed § Poses a possible trade restriction tool inspections, certification, quarantines § Goods that can transport egg masses nursery stock, logs with bark, Xmas trees § Vehicles, OHAs

Damage cont’d § US market is the largest export market for B. C. § California is extremely concerned with the GM threat § Washington, Oregon, Idaho, Montana, Calif. , etc. all conduct similar detection and eradication programs as B. C.

Damage cont’d § Ecological impacts § serious competitor to native leps § in east, change tree species diversity (remove oak) § most sensitive ecosystem is Canada’s most endangered: the Garry Oak Meadow § Oaks are the favoured host

Detection § Pheromone trapping § Deciding on a density § International standards § density related to previous year’s trapping results § § Egg mass sampling Tree banding (established populations only)

Trapping Protocol Nanaimo, 1999

Treatment § Spraying § Btk § Gypchek (virus) § § § Mass trapping Egg mass removal / Host removal Sterile male release Bio-control agents quarantines

Spraying Methods § Ground Spraying § vegetation specific § small areas can be treated § access limited § all day/ higher exposure rate to applicators and public § inconvenient to residents § can deny access

Spraying Methods § Aerial Spraying § fast, completed in morning § lowest cost per ha § proven effectiveness § can treat large areas § “fear” of overhead spraying - noise § aircraft safety § weather dependent

What is Btk? § § § Bacillus thuringiensis var kurstaki Naturally occurring soil organism Over 30 types of Bt only kurstaki is specific to caterpillars HD-1 strain most effective other varieties for mosquitos, black flies, grubs

Btk Mode of Action § 2 forms of bacterium § 1) vegetative (growing) form - noninsecticidal, common in soil § 2) spore (resting) + crystallized endo-toxin protein

Mode of Action § Larva feeds on leaf eats spores and crystals § alkaline gut dissolves crystal and enzymes break large protein into smaller toxic protein fragments § these fragments bind with receptors on mid-gut wall and causes “leaks” § death by bacterial infection and starvation

Mode of Action

Foray 48 B § One of many commercial Btk formulations (can’t patent Btk) § Foray 48 B the best for GM and other species § 2. 1% Btk, 90% water, 7. 9% inerts (proprietary ingredients) § secrecy of inerts creates controversy and hysteria § inerts = fermentation by-products, stabilizers, stickers, UV protectors, preservatives

Foray 48 B cont’d § Inerts improve the effectiveness of Btk by aiding spread, adherence to leaves, and protection from UV § Ingredients known by Health Canada’s PMRA & US EPA § formulation is a trade secret § Coke vs. Pepsi § rate: 4 l/ ha; about 1 coffee mug per average residential lot of which only a tablespoon is Btk

How to conduct an aerial spray § Get approval – legislation, gov’t backing, permits (PUP, DOT) § Get the budget § Buy the Btk § Get the contractors set up § Security § Communications – key to successful program

ISSUES § To address concerns of the EAB and public, 3 studies commissioned § Health surveillance study § song bird study § non-target lepidoptera § Results: § no significant impacts to humans or birds (confirms published info) § non-target leps were depressed (no surprise) ~ concerns with rare & endangered

“Believe it or not” § Aerial spraying brings out emotions mistrust of government, industry, unknown (too much X-files syndrome) § “Silent Spring” mentality § poor basic knowledge of biology, economics, health, concept of risk § 604 & 250 syndrome § BC highest users of alternative medicine

“Believe it or Not” § Spray responsible for: § § § rain over Oak Bay broken shower door dogs with runny noses dead turtles dead flocks of birds § “eerie stillness” around lake § sick horses § chronic fatigue, nausea, gout, failed marriages, etc. § causing a crazed bug to deliberately fly into his eye § mutated insects

Questions?