Diets containing pollen influence on fecundity and growth metrics in the ectoparasitoid, Habrobracon hebetor Say (Hym.: Braconidae).

Abstract

Habrobracon hebetor is a polyphagous and gregarious ectoparasitoid capable of parasitizing the larvae of various Lepidoptera pest species. This study investigated the effects of different pollen diets on the longevity, fecundity, and survival rate of adult H. hebetor wasps. The experiment utilized seven pollen diets, each with four replications, including a control along with rapeseed, apple, peach, almond, date, and honeybee pollen. While longevity was not significantly influenced by the pollen diets, fecundity showed a notable increase in the honeybee, rapeseed, and date pollen diets compared to the control. The honeybee and rapeseed diets resulted in the highest fecundity, placing them in the same category. Significant differences were observed in the values of the intrinsic rate of increase (r), gross reproduction rate (GRR), net reproduction rate (R₀), and doubling time (Dt) across the different pollen diets. The intrinsic rate of increase for H. hebetor was significantly higher when fed almond pollen (0.065 ± 0.003d^-1) compared to the other diets. The maximum gross reproduction rate (GRR) and net reproduction rate (R₀) were associated with the date pollen diet (3.38 ± 0.32 and 2.61 ± 0.39 female/female), respectively. The minimum population doubling time (Dt) was observed with the almond pollen diet (10.58 ± 0.6 d). Overall, pollen diets significantly impact the intrinsic rate of increase and other growth parameters of H. hebetor parasitoids. Almond, date palm, rapeseed, and honeybee pollen diets are particularly suitable for the mass rearing of this parasitoid wasp.