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

Longevity, survivorship, and fecundity of Trissolcusbasalis Wholaston were studied on sunn pest eggs at ۱۷.۵, ۲۰, ۲۵, ۲۷, ۳۰ and ۳۵˚C (all ±۰.۵), ۶۰±۵% RH and ۱۶:۸ h L:D. The preliminary results revealed an effect of temperature on the mentioned traits. In general, longevity decreased as temperature increased and ranged from ۵۳.۲۸±۵.۹ to ۱۰.۶۸±۱.۱۳ days when temperature leveled up from ۱۷.۵ to ۳۵ºC. Similarly, the highest and lowest fecundity was observed at ۲۵ and ۳۵˚C (۲۹۲.۴۰±۱۱.۱۴ and ۴۲.۱۶±۸.۶۲ eggs female-۱), respectively. Moreover, the developmental rate of adult parasitoids (۱/median longevity) was well described by modified model of Sharp-DeMichele in the range of studied temperatures and it was used to calculate physiological age. Likewise, the relationship between temperature and total realized fecundity was fitted well to a quadratic polynomial function. Conspicuously, age-specific cumulative fecundity rate was highly coordinated with exponential model and adult survivorship was fitted well to the reversed logistic curve. Finally, three temperature-dependent attributes viz., total fecundity, age-specific cumulative fecundity rate, and age-specific survivorship rate were used for T. basalisoviposition modeling. These findings may contribute to better understanding of oviposition strategy and behavior of T. basalis.

Keywords:

Trissolcus basalis , Oviposition model , temperature , Physiological age , Survival