Effects of ambient temperature,humidity, and age on wing-beat frequency of Periplaneta species

Wing-beat frequency of 2-week-old male Periplaneta americana cockroaches was measured during tethered flight at ambient temperatures from 19 to 35°C and 50 and 95% r.h. Between 19 and 27°C the frequency increased at a nearly constant rate (0·6 Hz/deg at 50% r.h.; 0·7 Hz/deg at 95% r.h.), but the rate of increase decreased markedly between 27 and 35°C. This decline differed from results of past investigations of wing-beat frequency for this species. Wing-beat frequencies at 95% r.h. were significantly higher than those at 50% r.h. for ambient temperatures between 27 and 35°C. reductions in wing-beat frequency at high temperatures and differences in wing-beat frequency between 50 and 95% r.h. may reflect decreases in internal thoracic temperature resulting from cuticular water loss.