Study Leads to Safer Caterpillar Insecticides

Experts predicted that Eastern tent caterpillars (ETC) would begin showing up in greater numbers in Central Kentucky this spring, making it an especially important time for area horse farms to be implementing control strategies. One such strategy might be a recently released product resulting from research to find ways to prevent mare reproductive loss syndrome (MRLS), which scientists generally link to ETC.

Based on data from a 2004 University of Kentucky (UK) College of Agriculture study on managing ETC, the J.J. Mauget Company, which manufactures injectable formulations of insecticides, fungicides, fertilizers, and antibiotics for tree care, released a new formulation of a compound called abamectin. The product, Abacide 2 (2% abamectin in 4 mL capsules) showed 100% control of ETC in UK trials.

Abamectin has low toxicity to people and livestock, and it's in the same insecticide class of anti-parasite medication already in use on pets and livestock. Managers can inject Abacide 2 directly into the tree, eliminating the logistical problems of spraying and containing any resulting drift.

According to Daniel Potter, professor of entomology at UK, the formulation shows good promise as a long-term ETC control strategy. He does caution, however, that the UK study was limited to one year and one site, and he recommends that farms start with a few trees in lower priority areas to see if this approach works well for them.

The research resulting in this new product was funded by the Grayson Jockey Club Research Foundation with the support of the Kentucky Thoroughbred Association/Kentucky Thoroughbred Owners and Breeders Association. Consulting arborist Larry Hanks also donated time and equipment to assist with the study. For more information see

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