Gypsy Moth in B.C.

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

2. 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

3. Biology

4. Biology

5. 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.

6. 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

7. Damage • Feeds on over 300 different shrub and tree species • Each caterpillar can eat up to 100 cm2 of foliage (two leaves per day for a late instar larva) • Outbreaks in hardwood forests in the east are very dramatic

8. Damage

9. Damage • Human Health • Masses of larvae covering everything • Hairs are “urticating” - allergies

10. 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

11. 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.

12. 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

13. 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)

14. Trapping ProtocolNanaimo, 1999

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

16. 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

17. 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

18. 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

19. Btk Mode of Action • 2 forms of bacterium • 1) vegetative (growing) form - non-insecticidal, common in soil • 2) spore (resting) + crystallized endo-toxin protein

20. 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

21. Mode of Action

22. 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

23. 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

24. 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

25. 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

26. “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

27. 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 “Believe it or Not”

28. Questions?