European Gypsy Moth ( Lymantria dispar)

1. European Gypsy Moth(Lymantria dispar)

2. Why be Concerned about Gypsy Moth? • Tree defoliator • Attacks over 300 species of woody plants • Increases host susceptibility to secondary pests and pathogens • Native range and established areas: appears as an outbreak pest • Greatest damage occurs at first introduction • Over 1 million acres defoliated in the U.S. in 2010

3. Local Impacts • Leaves are stripped • Trees are stressed, leaving them susceptible to other pests and diseases • Each caterpillar consumes 9 square feet of foliage! July ! Photo courtesy of Garrett (MD) County extension Office

4. Landscape Impacts • Photo courtesy of Garrett (MD) County Extension Office

5. Human Nuisance

6. Where is Gypsy Moth Established? • Europe and north Africa (native) • U.S. and Canada (invasive)

7. Identifying Gypsy Moth • Egg Masses • Caterpillars • Pupae • Adults (males vs. females)

8. Gypsy Moth Life Cycle

9. Egg Masses(laid in late summer, hatch in late spring) Each female lays one mass containing 500-1000 eggs Overwinter in a protected spot Emergence

10. Spot the Egg Mass

11. 6 pair of red spots 5 pair of blue spots Caterpillar (late spring through early summer) First instar larvae Larger caterpillars rest by day, eat at night

12. Spiny elm caterpillar Eastern tent caterpillar Whitemarked tussock moth fg = 2” fg = 1 3/4” fg = 1 1/3” Yellownecked caterpillar fg = 1 3/4” Forest tent caterpillar Fall webworm, fg = 1” fg = 1 3/4” Caterpillar Lookalikes Gypsy moth, fg = 2” MN Dept of Ag. Whitney Cranshaw

13. Feeding Damage • Entire leaf to midrib • Can cover acres of woody habitat

14. Host Preference

15. Pupa (Cocoon)(summer months) • Males smaller than females • Sparse silken threads • Found in protected spots • Bark crevices • Duff layer • 2 weeks

16. Feathered antennae Distinct “commas” on both top and underside of wings Adult(mid-summer to early fall) Female (does not fly) Male (daytime flier)

17. Mating Behavior • Females do not fly • Pheromone attracts males • Females lay one egg mass • Adults die, eggs overwinter

18. How Do Gypsy Moths Spread? Natural Artificial “Ballooning of larvae” Tourism Nursery stock Household moves Life stages are transported by humans 13-16 miles per year Populations expand 1¼ miles per year due to larval dispersal

19. Predators and Pathogens • Entomophaga maimaiga • NPV (nucleopolyhedrosis virus) • Mammals • Birds • Amphibians • Invertebrates NPV E. maimaiga

20. Factors That Influence Spread Rates • Early season temperatures & larval survival • Wind events & larval dispersal • Habitat & host abundance • Spring rains & disease incidence • Predator habitat & predation rates • PEOPLE through artificial introductions

21. National Gypsy Moth Management

22. Management Options • Bacillus thuringiensis var. kurstaki (Btk) • Common soil bacterium toxic to GM caterpillars • Halts feeding • Disparlure (mating disruption) • Targets adults • Reduces mating success • Diflubenzuron • Interferes with molting • Often used in nursery settings • Treatments in Minnesota have kept gypsy moth in check since 1980!

23. Treatments 2013 • Slow the Spread area only • No eradications necessary • Mating disruption • Covers • St. Louis County • Bear Head Lake SP • Superior National Forest • Cloquet State Forest

24. Which is Gypsy Moth Damage? • Leaf A • Leaf B • Leaf C A B C

25. Which is Gypsy Moth? • Tree A • Tree B • Tree C C A B

26. In What Life Stage of Gypsy Moth Would You Expect to Find Here • Egg masses • Caterpillars • Pupae • Adults