关键词: 木瓜榕传粉榕小蜂, 传粉者, 寄主定位, 触角, 感器, 超微形态, 超微结构

Abstract: The female parasitoids can sense host-plant odour via sensilla on the antennae, but little information is available on agaonid antennae. To explore the host location of Ceratosolen emarginatus Mayr (Hymenoptera: Agaonidae), experiments were designed to examine the types, distribution and ultramorphology of antennal sensilla in female adults of C. emarginatus and to determine the putative functions of the identified sensilla using scanning electron microscopy and transmission electron microscopy techniques. The results indicated that the geniculate antennae of female C. emarginatus are comprised of a basal scape, pedicel, and a long threadlike flagellum which is composed of 11 flagellomeres, but the third flagellomere bears a spine-like expansion. Eleven sensillar types were found and described on the antennae of female C. emarginatus. Of the identified sensillar types, uniporous and multiporous basiconic sensilla, elongated and rounded multiporous placoid sensilla, basiconic capitate peg sensilla and coeloconic sensilla type 1 are porous and may be involved in perception of host chemical cues. However, the aporous trichoid sensilla and chaetica sensilla may have mechanosensory functions, while the coeloconic sensilla type 2 and 3 may be involved in proprioception, thermo-hygroreception or pressure reception. Here, the specific sensilla, sensilla obscura, are thick, aporous, and aligned with the longitudinal antennal axis toward the scape. Sensilla obscura should be regarded as mechanoreceptors that may help pollinators to move through fig ostiole. The results will be helpful for understanding the specific behavioral characteristics of C. emarginatus. In addition, the detailed knowledge of antennal morphology may serve as a prerequisite for future electrophysiological tests in order to draw a chemical mediation and partition in fig-wasp communities.

Key words: Ceratosolen emarginatus, pollinator, host location, antennae, sensilla, ultramorphology, ultrastructure