The odorant receptor co‐receptor gene contributes to mating and host‐searching behaviors in parasitoid wasps

Abstract

Background: Biological control of pest insects by parasitoid wasps is an effective and environmentally friendly strategy compared with the use of synthetic pesticides. Successful courtship and host-search behaviors of parasitoid wasps are important for biological control efficiency and are often mediated by chemical odorant cues. The odorant receptor co-receptor (Orco) gene has an essential role in the perception of odors in insects. However, the function of Orco in the mating and host-searching behaviors of parasitoid wasps remains underexplored.Results: We identified the full-length Orco genes of four Drosophila parasitoid species in the genus Leptopilina, namely L. heterotoma, L. boulardi, L. syphax and L. drosophilae. Sequence alignment and membrane-topology analysis showed that Leptopilina Orcos had similar amino acid sequences and topology structures. Phylogenetic analysis revealed that Leptopilina Orcos were highly conserved. Furthermore, the results of quantitative real-time polymerase chain reactions showed that all four Orco genes had a typical antennae-biased tissue expression pattern. After knockdown of Orco in these different parasitoid species, we found that Orco-deficient male parasitoid wasps, but not females, lost their courtship ability. Moreover, Orco-deficient female parasitoid wasps presented impaired host-searching performance and decreased oviposition rates.Conclusion: Our study demonstrates that Orcos are essential in the mating and host-searching behaviors of parasitoid wasps. To our knowledge, this is the first time that the functions of Orco genes have been characterized in parasitoid wasps, which broadens our understanding of the chemoreception basis of parasitoid wasps and contributes to developing advanced pest management strategies.

Mutagenesis of Odorant Receptor Coreceptor Orco Reveals the Odorant-Detected Behavior of the Predator Eupeodes corollae

“…This result demonstrates that the detection of EBF by E. corollae is mediated by OR-dependent olfactory pathways. Likewise, among the four parasitoid species (Leptopilina heterotoma, Leptopilina boulardi, Leptopilina syphax, and Leptopilina drosophila), female parasitoid wasps lacking the Orco gene exhibited diminished host-searching capabilities [25]. These results suggest that the Orco gene plays a key role in the localization of prey by their natural enemies.…”

Functional Characterization of the Niemann–Pick C2 Protein BdioNPC2b in the Parasitic Wasp Baryscapus dioryctriae (Chalcidodea: Eulophidae)

“…15 Moreover, RNAi is considered a powerful technique for studying gene function in endoparasitic wasps. 47 Thus, we used this technique to investigate the function of BdioNPC2b in vivo. The dsNPC2b-treated B. dioryctriae individuals were insensitive to 2-butyl-2-octenal, however, the BdioNPC2b gene is not similar to VdesNPC2, which can directly mediate the reproduction of Varroa destructor.…”

“…The role of PperNPC2a, which is highly expressed in female adults of Phytoseiulus persimilis, was also proven via RNAi . Moreover, RNAi is considered a powerful technique for studying gene function in endoparasitic wasps . Thus, we used this technique to investigate the function of BdioNPC2b in vivo .…”

Female-Biased Odorant Receptor MmedOR48 in the Parasitoid Microplitis mediator Broadly Tunes to Plant Volatiles

“…26 In Leptopilina heterotoma, L. boulardi, L. syphax, and L. drosophilae, the Orco is essential in host-searching and mate-locating behaviors of Drosophila parasitoid wasps. 27 Microplitis mediator is a widely distributed solitary larval endoparasitoid wasp of lepidopterous pests including H. armigera, Mythimna separata, and Mamestra brassicae in Asia and Europe. 28,29 Previously, 166 ORs were identified in our laboratory based on transcriptome sequencing data, and most of them are orphan receptors.…”