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Identification & Biology
Trees Gypsy Moths Like
How Gypsy Moths Harm Trees
Where Gypsy Moths Are
Gypsy Moth Management
Slow The Spread (USFS and Indiana DNR)
For Homeowners
For Professionals
Quarantine Information
History of Gypsy Moths
Asian vs. European Gypsy Moth

Gypsy Moth Management for Professionals

Controlling Gypsy Moth Caterpillars

When other measures fail, applications of insecticides can be quite effective in killing caterpillars that are actively feeding on leaves and crawling on tree trunks. Two kinds of pesticides are available. Biological insecticides tend to have less of an impact on beneficial insects that keep other pests from becoming a problem. Of these Bacillus thuringiensis is the least toxic, only killing caterpillars. Spinosad kills wasps and bees as well as the caterpillars. Insect growth regulators like diflubenzuron and tebufenozide kill immature stages of other insects and crustaceans in streams. Chemical insecticides are the least selective materials available. In addition to killing gypsy moth caterpillars, they kill both beneficial and pest insects as well as fish and crustaceans in streams. The table below provides a list of materials that you can use to control the gypsy moth.

Aerial Application of Infested Tree Communities

If you live in an area where gypsy moth populations are large enough that defoliation of trees is likely, members of your community should consider banding together to hire an aerial applicator. Generally speaking, if there are more than 250 gypsy egg masses per acre during the winter, the area is likely to be defoliated in the following spring. Procedures such as the one described in this link can be followed by community groups or trained arborists to help communities determine whether defoliation is likely.

Aerial applications of insecticides are less expensive and more effective than applications applied from the ground. For a list of licensed aerial applicators in Indiana familiar with the laws for notifying residents and assuring safe flight distances from buildings, please select category 11 Aerial Applicators from this website

Ground Applications to Small Groups or Individual Trees

With the proper equipment, homeowners can spray trees up to 15 ft tall with an insecticide. Applying insecticides to trees much taller than this will require higher pressure sprayers that are available only to tree care professionals. Please view this website on how to hire a professional pesticide applicator.

General Comments on Insecticide Use

Make sure that the insecticides you choose are labeled for use against gypsy moth and then follow the label's directions. For more information, visit the Environmental Protection Ageny's "Citizen's Guide to Pest Control and Pesticide Safety."


Pesticide List - (Click here for a printable version of this Pesticide table - PDF)
Insecticide Formulation Amount Per 100 Gallons Amount Per Gallon Suggested Use General Use Restriction
(Check Label) H=Homeowner
75% S
15.6% EC
1/3 lb.
1 1/5 cup
1/3 tsp.
1 1/2 Tbsp.
Rescue H, C
Bacillus thuringiensis (Kurstaki)*
(Dipel, Biotrol, Others)
See label See label See label Biorational H, C
Bifenthrin (Talstar L&T and other site specific products) 0.7 F 5.5 -10.9 oz 1/3-2/3 tsp. Rescue H, C
Carbaryl (Sevin and others) 4 F
2 F
1 qt.
2 qt.
2 tsp.
4 tsp.
Rescue H, C
Chlorantraniliprol (Acelepryn) 1.67 SC 1-2 fl. oz. - Biorational C
Cyfluthrin (Tempo, Decathalon)
(Bayer Lawn & Garden)
20 WP
0.75 EC
1.9 oz.
1 Tbsp.
Rescue C
H (Bayer)
Deltamethrin (Deltagard T&O, Suspend SC) 4.75% EC 4-8 oz. 1/4-1/2 tsp. Rescue H, C
Fluvalinate (Mavrik) 2 F 5-10 oz. 1/4-1/2 tsp. Rescue H, C
Indoxacarb (Provaunt) 2.4 SC 1.2-2.5 fl. oz. - Biorational C
Lambda-cyhalothrin (Scimitar CS) 97% EC 1.5-5 oz. - Rescue H, C
Malathion 57% EC 2-4 pt. 2 tsp. Rescue H, C
Permethrin (Astro EC)
(Spectracide Bug Stop) (Eight)
36.8% EC
2.5% EC
4-8 oz.
1/4-1/2 tsp.
2 Tbsp.
Spinosad (Conserve)
Bulls-Eye Bioinsecticide, Fertilome Borer, Bagworm, Leafminer & Tent Caterpillar Spray
6 oz.
1/2 tsp.
4 Tbsp.
4 Tbsp.
Biorational C
Tebufenozide (Confirm) 25% EC 4-8 oz. 1/4-1/2 tsp. Biorational C

* Commonly Asked Questions About Btk (Bacillus thuringiensis var. kurstaki) PDF Publication

* Commonly Asked Questions About Btk (Bacillus thuringiensis var. kurstaki) PDF Publication

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