Development and Emergence of Telenomus chloropus and Trissolcus basalis (Hymenoptera: Scelionidae) at Various Temperatures and Relative Humidities

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Abstract
Effects of eight constant temperatures ranging from 15 to 36°C and eight constant relative humidities ranging from 64 to 100% RH on development and emergence of Telenomus chloropus Thomson and Trissolcus basalis (Wollaston) were determined using Nezara viridula (L.) eggs as hosts. Developmental time of T. chloropus was significantly greater than that of T. basalis at all study temperatures except 15°C. Average percent daily development of T. basalis became progressively larger than that of T. chloropus as temperature increased and was significantly greater at temperatures above 15°C. T. chloropus was unable to develop to the adult stage at temperatures exceeding 30°C; however, T. basalis completed development at all study temperatures. Percentage of parasitoids reaching the adult stage, percent emerging, and percent survival (egg to adult emergence) of T. basalis were significantly greater at both upper and lower extreme temperatures than those of T. chloropus. Average thermal requirement over the four intermediate temperatures (21–30°C), calculated using a base of 15°C, was 168 and 131 Celsius degree-days for T. chloropus and T. basalis, respectively. Both T. chloropus and T. basalis were able to develop successfully to the adult stage at all relative humidities studied. However, T. chloropus adults were able to emerge from host eggs only at 85% RH or higher. Survival from egg to adult emergence of T. basalis was significantly greater than for T. chloropus at all humidities studied.