Landowner Management

You are the first line of defense for protecting your property from damage by gypsy moth. Take time to inspect your trees, shrubs, structures, lawn objects, and recreational vehicles periodically for the various life forms of gypsy moth. And always check your car, recreational vehicles, and any other items you transport back and forth to make sure you aren't transporting invasive gypsy moth into areas not yet infested.

January - April: Remove and destroy egg masses

Every gypsy moth egg mass you destroy prevents 100 to over 1,000 caterpillars from hatching! Your efforts now will have the most impact.
-Search for egg masses on trees, firewood, outdoor furniture, and other outdoor surfaces. Look on the underside of objects, as the moths prefer to lay their eggs in protected areas.
-Scrape egg masses carefully into a container.
     *Try to gather and contain all of the eggs, as those that are left behind--even if they are on the
     ground--can survive and hatch.
     *Take care not to damage tree bark, which can leave the tree vulnerable to pests and disease.
-Soak the egg masses in a container of soapy water for 48 hours, then discard. You can also bury them in the dirt, or burn them (but not while they are on the tree!).
-Here is a helpful video showing how to remove gypsy moth egg masses.

March - April: Treat egg masses with biologic oil 

Once temperatures are above 45 Fahrenheit
-Saturate egg masses with Biologic Golden Pest Oil.
     *You can make your own biologic oil using a 1:1 ratio of soybean oil and water.
     *Use a small spray bottle, household sprayer, or supersoaker water gun to saturate the egg masses.

March - June: Chemical and mechanical controls
-Conventional chemical insecticides can effectively control gypsy moth caterpillars in some situations. Precautionary measures must be followed to avoid toxicity to humans, animals, and other non-target organisms. Make sure the product is effective on gypsy moth, and always follow all label instructions when using these or any other pest control product.
-Wrap trees with barrier bands to prevent caterpillar movement from tree to tree. Follow precautions to protect trees from damage.

May - August: Manage gypsy moth caterpillars, pupae, and moth populations

*The hairs of the caterpillar can be irritating to some, so wear gloves or use a broom or plastic knife to knock caterpillars onto the ground to step on them.
-Drop caterpillars into a bucket of strong soapy water and let sit for 48 hours.
-Spray caterpillars and moths directly with a strong soapy water solution. Be careful, as the mixture can make deck and walkway surfaces slippery.
-Monitor and maintain barrier bands.

*In hot, dry weather, water prized trees defoliated by gypsy moth. 

September - December: Leave egg masses in place
Do not remove egg masses until the Gypsy Moth Program completes its survey of gypsy moth egg masses to determine next year's spray map.

Inspections - Ongoing

We need everyone’s help in detecting gypsy moth populations and keeping this insect from spreading to new neighborhoods. Failure to inspect household articles for gypsy moth life stages prior to movement from a regulated area is a violation of U.S. Department of Agriculture quarantine regulations and may result in significant civil penalties.

Using Btk

To be most effective in minimizing defoliation, Btk - Bacillus thuringiensis var. kurstaki (commonly found in soil and on plants) - is applied by aerial spraying when the caterpillars are less than 1 inch long. When caterpillars eat Btk the protein crystals dissolve in their digestive system and become toxic. Within 1 to 2 days they die.

As caterpillars get larger, the efficiency of Btk diminishes. Btk has a reported residual activity (i.e., how long it remains potent) of about 1 week and is broken down by sunlight. Btk is only known to be toxic to feeding caterpillars of moths and butterflies and is quite safe to humans, birds, fish, pets, beneficial insects and other non-target organisms.