College of Agriculture
Veterinary Science	Mare Reproductive Loss Syndrome Index Page

May 30, 2002

Comment from Lee Townsend, Extension Entomologist
Department of Entomology
University of Kentucky College of Agriculture

Most eastern tent caterpillars are in the pupal stage, which for an individual, lasts about 3 weeks.  Differences in developmental rate of the caterpillars means that adult emergence and egg laying will occur over a span of several weeks.

An estimated 20% of the moths have emerged at this time.  Very little is known about their movement but there is evidence that ETC moths have a relatively high rate of dispersal.  Windy nights especially contribute to this by blowing moths beyond their normal flight range.

All eggs should be laid by mid-August.  This is a very conservative estimate, egg laying should be completed some time before that. Little is known about how ETC females find appropriate trees on which to lay eggs but airborne odors or contact with tree twigs may provide them with the clues that they need to select a place to lay eggs.  In the absence of wild cherry, the preferred host, they will seek alternative sites.