Egg deposition and protection of eggs in Chrysomelidae

Abstract

As the immobile stage insect eggs are most vulnerable and endangered. How are they protected against enemies, microbial disease, and desiccation? In chrysomelid eggs, several toxins and feeding deterrents of completely different chemical character are known and have been reviewed a few years ago by Pasteels et al. (1988a). In addition to toxic and deterrent defensive devices, eggs may be protected from enemies by mechanical barriers, which are of high diversity in Chrysomelidae; several of them are described by Von Lengerken (1954) and Hinton (1981). A chrysomelid female may even use its own body as a mechanical barrier either by guarding deposited eggs (parental care) or by shielding eggs during the entire embryonic development (ovoviviparity). An ovipositing female may also take care of the progeny by its choice of an oviposition site, which provides hatching larvae with sufficient protection and food. In Chrysomelidae, a few studies demonstrate that egg depositions are avoided at sites, which have already been infested by conspecifics (e.g. Van Alphen & Boer, 1980). In several species of the subfamily Chrysomelinae, females are known to be deterred from oviposition by the secretions of conspecific larvae (Hilker, 1989a).