Bracon wasps for ecological pest control–a laboratory experiment

PeerJ

article

Jessica Lettmann¹  Karsten Mody¹  Tore-Aliocha Kursch-Metz³  Nico Blüthgen¹  Katja Wehner¹ 

[1] Ecological Networks, Technische Universität Darmstadt;Department of Applied Ecology, Hochschule Geisenheim University;AMW Nützlinge GmbH

关键词: Biological pest control;    Braconidae;    Host number;    Oviposition behavior;    Sex ratio;    Temperature dependence;   

DOI  :  10.7717/peerj.11540

学科分类：社会科学、人文和艺术（综合）

来源: Inra

【 摘 要 】

Biological control of pest insects by natural enemies may be an effective, cheap and environmentally friendly alternative to synthetic pesticides. The cosmopolitan parasitoid wasp species Bracon brevicornis Wesmael and B. hebetor Say (Hymenoptera: Braconidae) use lepidopteran species as hosts, including insect pests like Ephestia kuehniella or Ostrinia nubilalis. Here, we compare the reproductive success of both Bracon species on E. kuehniella in a laboratory experiment. We asked (1) how the reproductive success on a single host larva changes with temperature, (2) how it changes with temperature when more host larvae are present and (3) how temperature and availability of host larvae influence the efficacy of Bracon species as biological control agents. In general, differences between B. brevicornis and B. hebetor have been small. For rearing both Bracon species in the laboratory on one host larva, a temperature between 20–27 °C seems appropriate to obtain the highest number of offspring with a female-biased sex ratio. Rearing the braconid wasps on more than one host larva revealed a higher number of total offspring but less offspring per host larva on average. Again, highest numbers of offspring hatched at 27 °C and the sex ratio was independent from temperature. Although no parasitoids hatched at 12 °C and only few at 36 °C, host larvae were still paralyzed. The efficacy of B. brevicornis was higher than 80% at all numbers of host larvae presented at all temperatures while the efficacy of B. hebetor was less than 80% at 12 °C and 27 °C at low numbers of host larvae presented. In conclusion, practitioners can use either B. brevicornis or B. hebetor at low and high temperatures and at varying host densities to achieve high pest control efficacy.

【 授权许可】

CC BY