Over the last two weeks, I have had countless calls about large quantities of caterpillars being around individuals' houses and trees. The caterpillars that everyone is dealing with are Eastern Tent Caterpillars. They are a nuisance which defoliates trees, make webs in trees, and are a pain to deal with when they are on your porch. However, they won't bite you and they will eventually go away.
Eastern Tent Caterpillars tend to be one of the first insects to come out in the spring. They are two inches long and are black with a white stripe down their back. Typically we only see one generation of them in a year and they are easy to control. If you find them in their web and are able to reach the web, then you should just pull it out and put it in some warm soapy water. If they aren't in the web, then you squash them or once again, put them in warm soapy water.
Now some individuals will tell you that they burn the web and that will control the insect, but burning the web is dangerous. If the flame you are using deviates from the targeted area, you could end up with your entire tree on fire. Therefore, I strongly recommend the warm soapy water method.
If soapy water isn't your ideal control method and you are open to using chemical control, then you can purchase a number of different pesticides. Some of the different active ingredients to look for in a pesticide include: Spinosad, Bacillus thuringiensis, acephate, carbaryl, permethrin, cyfluthrin, and deltamethrin. The first two active ingredients are biological pesticides which will kill the caterpillars without being too detrimental on beneficial insects and bees. If you use a pesticide, please remember to read and follow all label instructions.
For more information about Eastern Tent Caterpillars, please see Purdue Extension publication, Eastern Tent Caterpillars HN-68-W. You can locate this publication on the internet or by calling your local Purdue Extension Office.
As always, if you have any questions or would like information on any agriculture, horticulture, or natural resource topic, then please contact your local Purdue Extension Office at 448-9041 in Clay Co. or 829-5020 in Owen Co. or reach me directly at firstname.lastname@example.org Purdue University is an equal opportunity/equal access/affirmative action institution.
Upcoming opportunities available to you through Purdue Extension include:
May 22 - Plant Propagation, 6-6:45 PM, Owen County Public Library
May 26—Memorial Day—Extension Office Closed
May 31—Plant Propagation, 10-10:45 am, Owen County Public Library
June 13-14—Purdue Master Gardener Conference, Indianapolis, www.2014indymgconf.org