Development of Rhodnius prolixus (Hemiptera: Reduviidae) under Constant and Cyclic Conditions of Temperature and Humidity

Development of Rhodnius prolixus after eclosion until the adult stage was studied at constant temperatures (T), 15, 20, 25, 28, 35C, and relative humidities (RH), 75, 86 and 97%, and fluctuating (16/8 hr) temperatures, T I/II, 15/28C, 20/25C, 25/28C and 25/35C, and relative humidities, RH I/II, 86/75% and 97/75%. Eclosion or molting were not observed at 15C and 86 or 97% RH, respectively. At 35C and 75% RH only few insects molted. By alternating T I/II, 15/28C and 25/35C, insects developed at high frequency. Cumulating the average lengths of the interphases within independent groups for each instar, R. prolixus reached the adult stage most rapidly (86.7 days) and at highest frequency per instar (mean: 91.8%) at 28C and 75% RH. Under fluctuating T I/II, development was completed within 100 days or less at 25/28C and 25/35C with high rates of hatch and molting. Development was slowest at fluctuating TI/II, 15/28C and 20/25C (>185 days), and at constant 20C (>300 days). Mortality was higher at constant 97% RH or fluctuating RH I, 97%, than at constant or fluctuating 86% RH. Refeeding was minimal at optimal conditions of T and RH for development. The most refeeding was observed at a constant 35C.