干旱区生态环境知识资源中心

Species of Chrysolampus are widely distributed in arid regions of western North America and parasitize tychiine weevils that infest the seed pods of legumes. Detailed host information is presented for the first time: Chrysolampus sisymbrii parasitizes Tychius tectus in Astragalus inflexus and Chrysolampus schwarzi parasitizes Tychius lineellus in Lupinus leucophyllus. Data are presented on phenology, sex ratio, mating and oviposition behaviour of adults, and behaviour and development of larvae and pupae. Ovipositional promiscuity (i.e., eggs are equally likely to be laid in pods infested or unifested with weevil larvae) is documented in both species of Chrysolampus and discussed from a historical perspective. The immature stages of C. sisymbrii and C. schwarzi are described and illustrated using both light and scanning electron microscopy, and hypermetamorphic development is documented; the first-instar larva is morphologically distinct from the remaining larval instars. On the basis of both life history and morphology it is appropriate to refer to the first-instar larvae as planidia. The first-instar larva is sclerotized, mobile, and actively involved in host location and attack, and it is regarded as homologous to the planidia of the Eucharitidae and Perilampidae. Previous phylogenetic hypotheses regarding Chrysolampus, the Eucharitidae, and the Perilampidae are reevaluated and discussed in light of these new morphological, behavioural, and ecological data.