College of Agriculture
Veterinary Science	Mare Reproductive Loss Syndrome Index Page

March 21, 2002

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

A very small number of eastern tent caterpillar eggs began to hatch in west and central Kentucky on March 14 and 15.  At this point hatch has occurred on about 10% of the masses being monitored.  In central Kentucky this is about 2 weeks earlier than last year but right on the historical average for the insect.  Bud break and leaf expansion is just getting underway.  It is premature to consider an insecticide application.

The rate of eastern tent caterpillar egg hatch is strongly affected by temperature.  At a constant temperature of 77ºF, 90% of the eggs should hatch in about 8 days.  At 50ºF, it takes about 30 days for 90% of the eggs to hatch.  Very little, if any, activity will occur at temperatures below 50ºF.