First Detectors European Gypsy Moth (Lymantria dispar)

First Detectors Why be Concerned about Gypsy Moth? Tree defoliator Attacks more than 300 species of woody plants Increases host susceptibility to secondary pests and diseases Greatest damage occurs at first introduction Appears as an outbreak pest in its native range and established areas Over 1 million acres defoliated in the U.S. in 2010

First Detectors July ! Local Impacts  Leaves are stripped  Trees are stressed, susceptible to other pests and diseases  Each caterpillar consumes 9 ft 2 of foliage! Photo courtesy of Garrett (MD) County extension Office Garrett Co., MD Rocky Arbor State Park, WI

First Detectors Landscape Impacts Photo courtesy of Garrett (MD) County Extension Office Garrett County, MD 2007

First Detectors Human Nuisance

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

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

First Detectors Gypsy Moth Life Cycle

First Detectors Emergence Each female lays one egg mass containing eggs Overwinter in a protected spot Egg Masses (laid in late summer, hatch in late spring)

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6 pairs of red spots 5 pairs of blue spots Caterpillar (late spring through early summer) First stage larvae Larger caterpillars rest by day, feed at night

First Detectors Gypsy moth 2” Fall webworm 1” Whitemarked tussock moth 1 1/3” Yellownecked caterpillar 1 3/4” Eastern tent caterpillar 1 3/4” Forest tent caterpillar 1 3/4” Spiny elm caterpillar 2” Whitney Cranshaw MN Dept of Ag. Caterpillar Look-alikes [full grown length in inches]

First Detectors Feeding Damage Random feeding Entire leaf to midrib Can cover acres of woody habitat

First Detectors Host Preference Preferred eaten by all stages of larvae Oak, aspen, willow, white and river birch, basswood, larch, mountain-ash, alder and apple Hawthorn, hazelnut, hophornbeam, hornbeam, serviceberry, witch-hazel Less- preferred eaten only by older larvae Yellow birch, boxelder, butternut, black walnut, cherry, eastern cottonwood, elm, hackberry, hickory, red and sugar maple, pine, and spruce Blueberries, pin cherry, chokecherry, sweet fern Avoided rarely fed upon ash, cedar, fir, silver maple, catalpa, mulberry and many urban species Dogwood, elderberry, grape, greenbrier, juniper, raspberry, viburnum, and buckthorn!!

First Detectors Pupa (Cocoon) (summer months) Males smaller than females Attach by silken threads Found in protected spots Bark crevices Duff layer 2 weeks

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

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

First Detectors Pheromone-baited traps Delta: sticky interior, trap holds ~10 males Early Detection Milk carton: kill strip, trap holds ~1000 males Male moths lured in as they try to find females

First Detectors 2013 Traps Record moth numbers 90% caught in Lake & Cook counties Basis for treatment, regulatory decisions

First Detectors Trapping, Treatment and Regulations Minnesota Dept. of Agriculture uses trends in moth numbers over time and space to determine treatment locations and where moths are established

First Detectors Gypsy Moth Trends in Minnesota Main population is closer Mating success increasing

First Detectors Larval ballooning Populations expand 1¼ miles per year due to larval dispersal NaturalArtificial Tourism Nursery stock Household moves How Does Gypsy Moth Spread? Life stages are transported by humans miles per year

First Detectors Predators and Pathogens Entomophaga maimaiga NPV (nucleopolyhedrosis virus) Mammals Birds Amphibians Invertebrates

First Detectors Factors That Influence Spread Rates Early spring weather & larval survival spring cold snaps or heavy rains may cause mortality Wind events & larval dispersal Strong winds can carry caterpillars long distance but may not survive or be able to find mates Habitat & host abundance Broad diet helps them in tough times but drought may reduce survival Spring rains & disease incidence Cool, wet spring favors insect-killing fungi Predator habitat & predation rates Urban areas have fewer predators; moths tend to spread quickly through these corridors PEOPLE spread them artificially

First Detectors Population Stage Management Strategy Management Goal General infestation SuppressionTo protect high value resources by reducing outbreak populations BuildingSlow the SpreadTo reduce the population peaks beginning to coalesce along the “front” Pre-InfestationEradicationTo eliminate isolated outlier populations National Gypsy Moth Management

First Detectors Management Zones on the Move Legend

First Detectors 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

First Detectors Treatments in 2014 Slow the Spread management zone Mating disruption 11,743 acres (high dose) 40,738 acres (low dose) Btk 1,197 acres Covers St. Louis County Cities of Duluth, Proctor, Hermantown, West Duluth

First Detectors Treatments in 2014 Slow the Spread management zone Mating disruption 1,876 acres (low dose) Covers St. Louis County High Lake Superior National Forest

First Detectors Which is Gypsy Moth Damage? ABC A. Leaf A B. Leaf B C. Leaf C

First Detectors Which is Gypsy Moth? C B A A. Tree A B. Tree B C. Tree C

First Detectors Which Gypsy Moth Life Stage Would You Expect to Find Here? A. Egg mass B. Caterpillar C. Pupae D. Adult

First Detectors Which is a female gypsy moth? A. Moth A B. Moth B

First Detectors Which is a male gypsy moth? A. Moth A B. Moth B

First Detectors Which is gypsy moth? A. Insect A B. Insect B

First Detectors What killed these caterpillars? A. Btk B. Entomophage maimaige C. NPV D. Mating disruption

First Detectors Summary Gypsy moth is a destructive forest pest We have confidence in early detection systems Minnesota has prime habitat for defoliation Management takes advantage of behavior People are the main source of long-distance transportation and spread of gypsy moth Call MOTH or visit for more information about trapping and treatment

First Detectors Questions?