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  1st 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

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. spread throughout E. NA spread throughout E. NA

History in B.C.  First reported on plants imported from Europe (destroyed on dock)  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 Gypsy Moth web siteGypsy 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 - non- insecticidal, 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 48B  One of many commercial Btk formulations (can’t patent Btk)  Foray 48B 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 48B 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?