Apameles melanoscelus(Ratzeburg) females examined gypsy moth (Lymantria disparL.) silk more intensely in the afternoon than they did in the morning, but they examined it for decreasing lengths of time the longer they were exposed to it. This decrease was not due to a buildup of deterrent chemicals deposited by the female. Parasites were reactivated by holding them without silk for 60 min, indicating that habituation was involved. Parasites also remained active longer when increasing amounts of silk or hosts in conjunction with silk were presented to them.