Mass rearing of Bracon hebetor (Hym.: Braconidae) on wax moth, Galleria mellonella (Lep.: Pyralidae) with varying density of parasitoid and the host

Abstract

Rearing methods for Bracon hebetor (Say) (Hym., Braconidae) were investigated in the series of laboratory experiments designed to enhance the yield of the mass rearing of this parasitoid for biological control of lepidopteran field and stored product pests. In these experiments, the effects of parasitoid and host densities on fertility and sex ratio of B. hebetor were assessed. In parasitoid densities, 50 last-instar greater wax moth (GWM) Galleria mellonella (L.) larvae were placed per container and 1, 2, 4, 8 or10 pairs of B. hebetor (one male and one female) were released in each container. In host density study two pairs B. hebetor were introduce in six different densities (10, 20, 30, 40, 50 and 60) of host, GWM per container. A density of ten male-female pairs of B. hebetor produced a higher number of progeny (205 ± 7.07 adults) on 50 last instar larvae of GWM. Similarly, in a host density experiment, a density of 60 last instars GWM larvae produced a significantly higher number of parasitoid progeny (142.0 ± 8.75 adults), followed by 50 last instar larvae (141.0 ± 8.34 adults) among the tested host densities when two pairs of B. hebetor were used. The sex ratio of progenies was male-biased in all studies and there were no significant effects on sex ratio in various parasitoid and host densities. In mass rearing experiment, total number of emerged parasitoids per 200 wax moth larvae was 1091 ± 82.38 adults with mean parasitism rate of 98 ± 0.8%.

Habrobracon hebetor and Pteromalus cerealellae as Tools in Post-Harvest Integrated Pest Management

“…Egg dispersion by H. hebetor on larvae of P. interpunctella has been shown to decrease as the host density increased [43]. In a study by Rotary and Gerling, a high host parasitoid ratio increased the percentage egg hatch and adult emergence by H. hebetor when reared on G. mellonella [45]. In a study by Ghimire and Phillips, progeny numbers of H. hebetor parasitizing late instars of P. interpunctella were higher at high host densities compared to lower densities [44].…”

“…In a study by Ghimire and Phillips, progeny numbers of H. hebetor parasitizing late instars of P. interpunctella were higher at high host densities compared to lower densities [44]. The influence of host density on the sex ratio of H. hebetor has also been investigated [44,45,46,47]. A previous study showed that the offspring sex ratio (male/total) increased with decreasing host/parasitoid ratio [47].…”

Present and future perspectives of using biological control agents against pests of honey bees

“…and Apanteles galleriae (Wilkinson) (Hymenoptera: Braconidae), are potential biocontrol agents to wax moths (Kwadha et al 2017). A. galleriae causes disturbance in development and alterations in the endocrine system of GWM larvae (Wanl et al 1994), while the venom of B. hebetor showed negative effects on GWM reducing oxygen consumption of larvae (Waller 1965), meanwhile GWM can be used for mass rearing of B. hebetor (Alam et al 2015). In fact, these two parasitoids attack wax moth larvae in stored combs outside hives or inside empty hives.…”

Efficacy of the larval parasitoid, Bracon hebetor Say. (Hymenoptera: Braconidae) on the greater wax moth larvae, Galleria mellonella (L.) (Lepidoptera: Pyralidae) under laboratory and field conditions

“…B. hebetor is considered one of the best potential biological control agents for stored-product insects in the family Pyralidae (Brower et al 1996). B. hebetor females paralyze their hosts, which are typically last-stage larvae in a "wandering" phase, by stinging them, injecting paralytic venom, and ovipositing variable numbers of eggs on or near the surface of paralyzed hosts (Alam et al 2015).…”