SURVIVORSHIP OF IMMATURE STAGES OF EURYPEDUS NIGROSIGNATUS BoHEMAN (CHRYSOMELIDAE: CASSIDINAE: PHYSONOTINI) IN CENTRAL PANAMA

Larvae of the leaf beetle Eurypedus nigrosignatus Boheman carry fécula and cast skins on their dorsa forming a protective device, commonly called a fecal shield. Survival from egg to adult eclosión, natural enemies, and relation to its hostplant, Cordia curassavica (Jacq.) Roem. and Schult. (Boraginaceae) were assessed. Overall survival was 2%; eggs and fourth instars were less susceptible to enemies than were early larval stages and pupae. Prédation accounted for the low survival of larvae, whereas parasitism for a low success rate of pupae. Six different predators including three spiders (Arachnida), a pentatomid, a reduviid (Heteroptera), and an ant (Hymenoptera) were observed. Reared parasitoids included a chalcidid (Hymenoptera) and a tachinid (Diptera). The fecal shield increases in size throughout larval development; however, the shield of prepupal individuals is partially lost. Shield chemical content very closely reassambles that of a particular host plant. Although the lower terpenoid concentration (per weight) in shields decreases with larval development, bigger shields as a unit contain larger amounts. Adults spend the Panamanian dry season buried in the ground directly under host plants. Eurypedus nigrosignatus is under intense selective pressures in Central Panama.