Effect of Bacillus thuringiensis on Habrobracon hebetor during combined biological control of Plodia interpunctella

Abstract

The suitability of combining microbial pesticides and an insect parasitoid for pest management of stored cereal in China was evaluated using laboratory assays. For this purpose, interactions between Bacillus thuringiensis (Bt), Bt-intoxicated host larvae and the parasitoid Habrobracon hebetor (Say) (Hymenoptera: Braconidae) were tested against Plodia interpunctella Hübner (Lepidoptera: Pyralidae). Bt or H. hebetor alone caused 41.67% and 35.35% P. interpunctella larval mortality respectively. The Btparasitoid combined treatment significantly increased mortality of P. interpunctella (86%). Progeny development of H. hebetor was dependent upon its susceptibility to Bt. Fewer parasitoids emerged from Bt-parasitoid combined treatment than in non-Bt treatments. However, since Bt did not prevent parasitoid development, a combined treatment with Bt and parasitoid release could produce better protection against P. interpunctella than either treatments when used singly, because their lethal effects were additive to each other.

Responses to a warming world: Integrating life history, immune investment, and pathogen resistance in a model insect species

“…Recent work has shown that temperature effects on Plodia immune parameters are strongly dependent on other environmental factors, indicating complex trade-offs within the system (Triggs & Knell, 2012). Given its propensity for global proliferation, much Plodia research has focused on the development of biopesticides as control strategies (e.g., Giles, Hellmich, Iverson, & Lewis, 2000;Oluwafemi, Rao, Wang, & Zhang, 2009). However, to date, no work has linked the relationship between environmental temperature, effects on life-history and immune measures, and subsequent outcomes for host-pathogen interactions.…”

Host location and acceptance by parasitoid, Habrobracon hebetor and effect of varying Bacillus thuringiensis treatment against rice moth, Corcyra cephalonica

“…Bioassay of Bt on Corcyra cephalonica was carried out as per Oluwafemi et al (2009). Dipel DF was serially diluted using 1, 2, 4, 8, 16, 32 and 64 mg per mL of distilled water.…”

“…The experiment was replicated five times. LC 50 for 48 h was used in further experiments (Oluwafemi et al, 2009). Also, LC 25 and LC 10 for 48 h were used to prepare Bt treated diets to rear host larvae for mortality experiments.…”

“…Integrating B. thuringiensis with a parasitoid has shown satisfactory control of lepidopterous pests (Blumberg et al, 1997). Bt has been shown to have no adverse effects on parasitoid development or its emergence when used against pest populations (Weseloh and Andreadis, 1982;Ulpah and Kok, 1996;Oluwafemi et al, 2009). Surgeoner and Farkas (1990) have recommended the use of Bt insecticide, such as Dipel, for use in integrated pest management programs and they have also shwed that it is harmless to most of the beneficials tested.…”

“…Surgeoner and Farkas (1990) have recommended the use of Bt insecticide, such as Dipel, for use in integrated pest management programs and they have also shwed that it is harmless to most of the beneficials tested. Oluwafemi et al (2009) have reported that a combination of Bt with H. hebetor as a biological control agent, resulted in successful control of Plodia interpunctella population and has recommended the use of Bt in combination with a parasitoid for the control of other lepidopteran pests. However, Erb et al, (2001) reported that Bt can adversely affect certain parasitoids by causing enhanced or decreased parasitoid larval development times and altered parasitoid sex ratios (Erb et al 2001).…”