BEHAVIORAL-STUDIES ON MALACOSOMA-DISSTRIA (LEPIDOPTERA-LASIOCAMPIDAE)

First-stage forest tent caterpillar larvae were tested for the presence of active and sluggish behavior types such as Wellington found in Malacosoma californicum pluviale (Dyar). Larvae capable of directed movement towards a 30 W light source were classified as active. Larvae were tested on 3 consecutive days, and only a small percentage responded on all 3 days. A much larger percentage remained sluggish throughout the period. Chi-square tests confirmed that the differences in response were not random. There was a tendency for some larvae to respond to light during the test and for others not to respond. The reduced consistency in the response of active larvae in M. disstria Huebner compared with that reported for M. c. pluviale may be partly due to real behavioral differences, but it also may be partly due to some procedural differences between these tests and Wellington''s.