For immediate release: Apr 20, 2011
Posted by: [DNR]
Contact: Phil Marshall
Phone: (317) 232-4189

Gypsy moth treatments may begin week of May 9

Aerial treatments to slow the spread of gypsy moths in selected areas of Allen, Lake, and Porter counties could begin the week of May 9.

The exact timing of the treatments depends on weather conditions. If the weather cools and slows the emergence of the caterpillars, treatments could be delayed until the week of May 16. Updates will be posted at DNR also will issue updates to local media. Detailed maps of the treatment sites are at

If rain or high winds develop once a treatment begins, the treatment will be halted and rescheduled for the next suitable day. Treatment will then resume until all sites are completed.

With the exception of the Porter County site, which will receive only one treatment, all sites will receive two treatments spaced approximately four to 10 days apart. The timing of second treatments is also weather dependent, although the schedule is the week of May 16.

During treatments, people will see a yellow crop duster airplane flying 50-125 feet above the treetops, starting at sunrise and continuing throughout the day as long as the weather and flight schedules permit. With favorable weather, treatments should be completed by late morning or early afternoon.

The airplanes distribute a fine spray containing the bacteria Bacillus thuringiensis var. kurstaki, often referred to as Btk, into the treetops of infested areas where gypsy moth caterpillars feed. Btk occurs naturally in soil. Btk kills gypsy moth caterpillars as they feed on tree leaves by disrupting their digestive systems.

Btk has been used for decades by organic gardeners and has an excellent safety record with people and animals. People who live or work near the treatment areas might choose to take common-sense precautions, including staying inside when the planes are flying, and for about 30 minutes after treatments are complete. This gives the material time to settle out of the air and adhere to treetops. People with questions may call toll-free at 1-866-NO-EXOTIC (663-9684) or call their county extension office at 1-888-EXT-INFO (1-888-398-4636).

To determine if your property is in the treatment areas and for more information about gypsy moth, see

« Back to News Release List

Link to this event:

Gypsy moth treatments may begin week of May 9 Apr 20, 2011 content_id:748CCBB011974834B0501D769C76E1A0; type:press; agency:DNR; showOnHomepage:; sortDate:Apr 20, 2011; filterDate:201104; isBanner:no; agencyDivision:DNR;04 - April;2011;Press Release;Show on Home