Temperature influence on the nymphal biology of Dichelops melacanthus (Dallas, 1851) (Heteroptera: pentatomidae)

Abstract

Performane of nymphs of the green belly bug, Dichelops melacanthus (Dallas, 1851), under three different temperatures (15, 20 e 25oC) was evaluated in the laboratory. It was impossible to evaluate the temperature effect since egg stadium, because no nymph ecloded under 15 and 20oC. D. melacanthus nymphs were maintained under those different temperatures since the first stadium. Upon reaching the second instar, they were placed individually in Petri dishes and fed with green pods and dry seeds of soybean. The environmental cahambers were maintained with relative humidity of 65±5% and photophase of 14 hours. Nymphs maintained under 15oC showed 100% of mortality on the second instar. Under 20oC, only one adult emerged; the total mortality (2nd-5th instar) was about 96,7%. Under 25oC, 56% of nymphs completed their development, becoming adults. The single nymph (male) from 20oC required 56.0 days to complete development. The developmental time (2nd-5th instar) under 25oC was 24.8 and 24.0 days, for females and males, respectively. These results suggest that D. melacanthus was not able to develop under mild temperatures (15oC e 20oC) in the laboratory.