DIEL ACTIVITY CYCLES IN NYMPHAL STADIA OF THE GERMAN-COCKROACH (DICTYOPTERA, BLATTELLIDAE)

Computerized moving-image analysis was used to determine movement beha vior of individual German cockroach, Blattella germanica (L.), nymphs (second and fifth instars) between food, water, and harborage resource sites. Both second and fifth instars (n = 10) were examined for the e ntire nymphal stadium, during which a 12:12 (L:D) photoperiod was main tained. In addition, corresponding resource consumption rates for thes e nymphal stages also were determined. Both nymphal stages exhibited a pattern of high activity for the first half of the nymphal stadium, e specially during each scotophase. For the last third of the Stadium, t he nymphs remained continuously in the harborage, moved very little, a nd consumed little or no resources. We discuss implications of these f indings regarding control, future research, and possible hormonal beha vior regulation.