European Gypsy Moth ( Lymantria dispar)

European Gypsy Moth(Lymantria dispar)

Why be Concerned about Gypsy Moth? • Tree defoliator • Attacks over 300 species of woody plants • Increases susceptibility to secondary pests and pathogens • Native range and established areas: appears as an outbreak pest • Greatest damage occurs at first introduction • 425,000 acres were defoliated in the U.S. in 2009

Impacts • Gypsy moth is a tree defoliator • Trees are stressed, leaving them susceptible to other pests and diseases July Widespread defoliation in Wisconsin caused by gypsy moth • Each caterpillar consumes 3 square feet of foliage!

Human Nuisance

Where is Gypsy Moth Established? • Europe and north Africa • U.S. and Canada

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

Gypsy Moth Life Cycle

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

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

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

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

Host Preference

Gypsy Moth Damage Risk Model (2004)

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

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

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

Early Detection • Pheromone Lure Traps • Male moths are caught as they try to find a mate • Sticky interior

2004 2005 2008 2007 2003-2009 Trap Catch Trends 2006 2009

Gypsy Moth in Minnesota • Detection program in Minnesota started in 1973 • Rapid increase due to nearing of the first wave

How Do Gypsy Moths Spread? Natural Artificial Tourism “Ballooning of larvae” 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

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

National Gypsy Moth Management

Gypsy Moth Control Options • Bacillus thuringiensis var. kurstaki (Btk) • Common soil bacterium toxic to gypsy moth caterpillars • Halts feeding • Disparlure (mating disruption) • Targets adults • Reduces mating success • Diflubenzuron • Interferes with molting • Often used in nursery settings • Controls have kept Minnesota gypsy moth-free since 1980!

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

Which is Gypsy Moth? • Insect A • Insect B • Insect C A C B

Where is Gypsy Moth? • Site A • Site B • Site C A C B

What Life Stage of Gypsy Moth Would You Look For? • Egg Mass • Caterpillar • Pupa • Adult

Is this Gypsy Moth? • Yes • No • Not Sure

Who Made This Mess? • Emerald Ash Borer • Asian Longhorned Beetle • Gypsy Moth • Can’t tell from here • I didn’t do it

Which is Gypsy Moth? • Left tree • Right tree

Summary • Gypsy moth is a destructive forest pest • Confidence in early detection systems • Minnesota has prime habitat for defoliation • Management takes advantage of behavior • Larval feeding • Mating • People are the main source of long-distance transportation and spread of gypsy moth • Call 888-545-MOTH or visit www.mda.state.mn.us/gypsymoth for more information about trapping and treatment

European Gypsy Moth ( Lymantria dispar)