Illinois Department of Agriculture Expands Gypsy Moth Quarantine

Date: Monday, April 10, 2017

SPRINGFIELD, IL - Four additional northern Illinois counties have been placed under quarantine to control the spread of the gypsy moth, a destructive pest that destroys trees and shrubs.

Kendall, Kane, LaSalle and Will counties will join Cook, DuPage, Lake and McHenry counties in the Department's quarantine order.  Lake County was the first county in Illinois to be quarantined, which was established in 2000.

"The gypsy moth population in these counties has reached a critical level where steps need to be taken to protect other areas of the state from this destructive pest," said Deputy Director and Environmental Programs Bureau Chief Warren Goetsch.  "These counties will remain eligible for participation in the gypsy moth control program, and the Department will continue to aggressively treat the leading edge of the infestation in these counties." 

The gypsy moth is a non-native pest.  Large populations of the pest are capable of stripping plants bare, leaving them susceptible to disease and environmental stressors. Severe defoliation can cause tree death. Unlike the emerald ash borer, another non-native pest which feeds exclusively on ash trees, the gypsy moth is not a picky eater.  It will devour almost anything leafy and green, as it feeds on over 250 species of plants, however it especially prefers oak and willow trees. 

Under the quarantine, all nursery and lumber products must be inspected or certified before they can be transported out of the eight counties.  In addition, residents of these counties must personally inspect vehicles, tents, outdoor lawn furniture, bicycles and other outdoor items for gypsy moth egg masses, live moths and caterpillars before taking them out of the quarantine zone.

Anyone convicted of illegally removing prohibited items from the quarantine area may be fined up to $500, and the items themselves must be either immediately removed from the non-infested area or immediately destroyed.

Male gypsy moths are brown with black markings and have a wingspan of an inch-and-a-half.  Female gypsy moths are slightly larger and typically white or cream-colored.  The females cannot fly because of the weight of their eggs.

The Department, in conjunction with the United States Forest Service, plans to treat more than 54,000 acres for the pest this year, including locations in DeKalb, LaSalle, Livingston, Carroll, Jo Daviess, Stephenson, Ogle, Will, and Kendall counties.  Each site will receive an application of either 1) BtK, a naturally-occurring bacteria used as an environmentally friendly alternative to chemical pesticides, or 2) Pheromone, a sexual attractant that confuses male gypsy moths and prevents them from breeding.   The BtK will be applied by helicopter or airplane in late April or mid-May, weather pending, with a second application being done within the following two weeks.  Meanwhile, airplanes will apply the pheromone flakes in late June.  People who live or work near the application site may want to stay indoors for 30 minutes to allow time for material to settle out of the air.

A list of the impacted sites and their scheduled treatments follows: 

Table 1.  Proposed Treatments for Gypsy Moths in Illinois 2017
Block - Area NameCountyTreatment TypeEstimated Treatment Acres
LaSalle 1LaSalleBtk1750
Plano 1KendallBtk775
Plano 2KendallBtk250
Starved Rock 1LaSalleBtk11000
Wilmington 1WillBtk469
Yorkville 1KendallBtk3000
TOTAL proposed Btk6 blocks, 3 counties 17244


Table 1.  Proposed Treatments for Gypsy Moths in Illinois 2017 (cont.)
Block - Area NameCountyTreatment TypeEstimated Treatment Acres
Byron 1OgleMD800
Fairbury 1LivingstonMD5500
Fairbury South 1LivingstonMD1000
Forrest South 1LivingstonMD1000
Freeport West 1StephensonMD4000
Hanover 1Jo DaviessMD7600
Loran 1CarrollMD400
Northwest Pontiac 1LivingstonMD5000
Streator North 1LaSalle / LivingstonMD11500
Waterman 1DeKalbMD400
TOTAL proposed MD10 blocks, 7 counties 37200