An Integrated Biological Control Using an Endoparasitoid Wasp (Cotesia plutellae) and a Microbial Insecticide (Bacillus thuringiensis) against the Diamondback Moth, Plutella xylostella

Abstract

All tested Korean populations of the diamondback moth, Plutella xylostella, are known to be resistant especially against pyrethroid insecticides by mutation in its molecular target, para-sodium channel. Moreover, P. xylostella is able to develop resistance against most commercial insecticides. This study was performed to develop an efficient control technique against P. xylostella by a combined treatment of an endoparasitoid wasp, Cotesia plutellae, and a microbial insecticide, Bacillus thurigiensis. To investigate any parasitism preference of C. plutellae against susceptible and resistant P. xylostella, five different populations of P. xylostella were compared in insecticide susceptibilities and parasitism by C. plutellae. These five P. xylostella populations showed a significant variation against three commercial insecticides including pyrethroid, organophosphate, neonicotinoid, and insect growth regulator. However, there were no significant differences among five P. xylostella populations in their parasitic rates by C. plutellae. Moreover, parasitized larvae of P. xylostella showed significantly higher susceptibility to B. thuringiensis. As an immunosuppressive agent, viral ankyrin genes (vankyrins) encoded in C. plutellae were transiently expressed in nonparasitized larvae. Expression of vankyrins significantly enhanced the efficacy of B. thuringiensis against the third instar larvae of P. xylostella. Thus an immunosuppression induced by C. plutellae enhanced the insecticidal efficacy of B. thuringiensis. These results suggest that a combined treatment of C. plutellae and B. thuringiensis may effectively control the insecticide-resistant populations of P. xylostella.

Identification of immune‐related genes from the transcriptome of the venom gland in Cotesia plutellae

“…Cotesia plutellae (Hymenoptera: Braconidae) is an endoparasitoid wasp that parasitizes on the larvae of the diamondback moth, Plutella xylostella , and the fall webworm, Hyphantria cunea (Kim et al 2004). The female adult of C. plutellae lays eggs in the hemocoel of P. xylostella larvae, and the eggs hatch in the host and spend the larval stage ingesting the host's tissues or nutrients.…”

Insecticidal Effect of Organic Materials of BT, Neem and Matrine Alone and Its Mixture against Major Insect Pests of Organic Chinese cabbage

“…그러나 미생물 농약인 BT와 프루텔고 치벌(Cotesia plutellae)을 피레스로이드계 농약에 저항성을 보이는 배추좀나방에 혼합 처리하였을 때 프루텔고치벌이 배추좀나방의 면역력을 저하시켜 효과적으로 방제할 수 있 다고 보고하였다 (Kim et al, 2013). 본 연구는 기존에 알려진 유기농자재들의 실제적인 효과 검토가 미흡하여 사용자들에게 혼란을 야기하고 있어 유기농 배추 주요 해충을 효과적으로 방제할 수 있는 친환경자재인 Matrine, Neem, 비티(BT; B. thuringiensis)의 유기농 배추 주 요 해충에 대한 살충성을 조사하기 위해 수행되었다.…”