Seasonal Variation in Adult Longevity of Aleoides percurrens Lyle (Hymenoptera: Braconidae), a Larval Parasitoid of Poplar Defoliator Clostera cupreata Butler

Seasonal variation in adult longevity of Aleoides percurrens Lyle was studied with respect to ambient temperature and relative humidity from April to early December for 2 years (1991- 1992) at Forest Research Institute, Dehra Dun (78°01' N latitude 77° 59' E longitude), India. Longevity was studied in presence of food (honey-sugar solution) and in the absence of host .larvae. Parasitoid longevity peaked in September (12.8 ± 2.8 days) when mean relative humidity was 81.0 ± 2.1% (69-93%) and mean temperature was 24.2 ± 2.7°C (19.2-31.3°C). Longevity was shortest in April (3.0±1.0days) when the mean relative humidity was 54.5±5.1% (36-75%) and mean temperature was 21.3±2.3°C (10.7-32.0°C). A high significant and positive correlation (r = 0.6604) was established between relative humidity and adult longevity. The linear and square relationships established are given by the expressions [Longevity = -7.9127 + 0.22049 (RH), R² = 0.4361, P2), R² = 0.4607, P < 0.001, respectively]. However the correlation between ambient temperature and adult longevity was non-significant (r = 0.0174).