Oviposition Model of Trissolcus basalis Wholaston (Hym.: Scelionidae) on Sunn Pest Eggs

Abstract

Longevity, survivorship, and fecundity of Trissolcusbasalis Wholaston were studied on sunn pest eggs at 17.5, 20, 25, 27, 30 and 35 ̊C (al l ±0.5), 60±5% RH and 16:8 h L:D. The preliminary results revealed an effect of temperatu re on the mentioned traits. In general, longevity decreased as temperature increased and ra nged from 53.28±5.9 to 10.68±1.13 days when temperature leveled up from 17.5 to 35ºC. Similarly, the highest and lowest fecundity was observed at 25 and 35 ̊C (292.40±11.14 and 42.16±8.62 eggs female -1 ), respectively. Moreover, the developmental rate of a dult parasitoids (1/median longevity) was well described by modified model of Sharp-DeMic hele in the range of studied temperatures and it was used to calculate physiolog ical age. Likewise, the relationship between temperature and total realized fecundity wa s fitted well to a quadratic polynomial function. Conspicuously, age-specific cu mulative fecundity rate was highly coordinated with exponential model and adult surviv orship was fitted well to the reversed logistic curve. Finally, three temperature-dependen t attributes viz., total fecundity, age- specific cumulative fecundity rate, and age-specifi c survivorship rate were used for T. basalis oviposition modeling. These findings may contribute to better understanding of oviposition strategy and behavior of T. basalis . Keywords: Oviposition model, Physiological age, Survival, Tem perature, Trissolcus basalis.