Functional Morphology of the Antennae and Sensilla of Coeloides qinlingensis Dang et Yang (Hymenoptera: Braconidae).

Abstract

Simple SummaryThe wasp Coeloides qinglingensis (Hymenoptera: Braconidae) parasitizes insects that damage pine trees, so it is a potential biocontrol agent. Here, we used scanning electron microscopy to examine the fine morphology of the antennae of the adults, as well as the type, shape, and distribution of antennal sensilla. We detected sexual dimorphism in antennal flagellar length, and observed nine morphological types of antennal sensilla. Importantly, dome-shaped sensilla and sensilla auricillica are reported for the first time for C. qinlingensis in this study. Their shape differs from that of sensilla described in other parasitic wasp species. We discuss the potential functions of the sensilla of C. qinlingensis through comparisons with those of sensilla of other parasitic wasps, including braconid wasps that parasitize concealed insect hosts. This information provides a solid foundation for further studies on the chemical communication and behavior of C. qinlingensis.Coeloides qinlingensis Dang et Yang, 1989 (Hymenoptera: Braconidae) is a biocontrol agent of several scolytid pine pests in Southwest China. We examined the fine morphology of the antennae of adult C. qinlingensis, as well as the type, shape, and distribution of antennal sensilla, via scanning electron microscopy. The antennae of female and male C. qinlingensis are filiform and comprise a scape, pedicel, and 31–36 flagellomeres. We detected sexual dimorphism in antennal flagellar length but not in the length of other subsegments. A total of nine morphological types of antennal sensilla varying in cuticular pore structure are present in both sexes, including nonporous types (sensilla trichodea, sensilla chaetica (2 subtypes), and sensilla coeloconica); apical pore types (sensilla basiconica and sensilla auricillica); and multiporous types (dome-shaped sensilla and sensilla placodea (2 subtypes)). Dome-shaped sensilla and sensilla auricillica are reported for the first time for C. qinlingensis, and their shape differs from that of sensilla in other parasitic wasps. The functional morphology of the sensilla of C. qinlingensis was compared with that of the sensilla of other parasitic wasps, including those that parasitize concealed insects. This information provides a foundation for further research on the chemical communication and behavior of C. qinlingensis.