The effect of plant- and parasitoid-induced egg mortality on the interspecific distribution of an oligophagous herbivore.

摘要: Plant-mediated egg mortality varied greatly for the oligophagous leafhopper, Carneocephala floridana, a common inhabitant of salt marshes along Florida's Gulf coast. In laboratory, survivorship from to first instar was generally greater on two herbaceous plants. Borrichia frutescens and Salicornia virginica (80 81% respectively) than it grasses, Distichlis spicata Spartina alterniflora (41 77% respectively). Although C. floridana laid significantly more eggs per clutch Sp. species, this increase in number offset by higher species. The greatest source identifiable plant-mediated death due desiccation leaf tissue surrounding clutch. addition, field experiments which four host species were infested with at natural densities consistently yielded parasitism rates mymarid wasps regardless background switches plants seasonally, using grass mainly during winter months, when experience substantial dieback. are nutritionally superior as food floridana. reared herbs produce larger, fecund, adults they do grasses (Rossi 1991). However, cold snaps while less "attractive", may provide most abundant nutritional ovipositional resources available results study indicate how variable plant-and parasitoid-mediated work synergistically interspecific status explain switching insect.