Salivary α-Amylase of Stem Borer Hosts Determines Host Recognition and Acceptance for Oviposition by Cotesia spp. (Hymenoptera, Braconidae)

• Published in: Frontiers in ecology and evolution Vol. 6
• Main Authors: Bichang'a, Gladys B., Lage, Jean-Luc Da, Sambai, Kevin, Mule, Simon, Ru, Bruno Le, Kaiser, Laure, Juma, Gerald, Maina, Esther N., Calatayud, Paul-André
• Format: Journal Article
• Language: English
• Published: Frontiers Media 19.12.2018; Frontiers Media S.A
• Subjects: Cotesia flavipes; Cotesia sesamiae; Cotesia typhae; Ecology, environment; host specificity; Life Sciences; parasitic wasp; protein perception; Symbiosis
• ISSN: 2296-701X; 2296-701X
• DOI: 10.3389/fevo.2018.00228

Foraging insect parasitoids use specific chemical cues to discriminate between host and non-host species. Several compounds have been identified in “host location and acceptance.” However, nothing is known about the molecular variations in these compounds that could account for host-range differences between parasitoid species. In a previous study, it was shown that during the host-finding process, contact between the braconid Cotesia flavipes and its host is crucial, and that α-amylase of oral secretions from the host plays a key role for host acceptance and oviposition by the parasitoid. The present study sought to establish whether the variations in this enzyme could explain specific host recognition in different host-parasitoid associations. Different species and populations of the C. flavipes complex specialized on graminaceous lepidopteran stemborers were used. Electrophoresis of α-amylase revealed different isoforms that mediate the parasitoid's oviposition acceptance and preference for a specific host. This discovery opens up new avenues for investigating the evolutionary processes at play in chemically-mediated host specialization in the species-rich Cotesia genus.