Crowding and Host Plant Nutrition: Environmental Determinants of Wing-form in Prokelisia marginata

摘要: Prokelisia marginata is a wing—dimorphic planthopper that feeds on the phloem sap of intertidal marsh grass Spartina alterniflora. Populations are comprised two wing—forms: flightless brachypters and macropters, which can fly. Macropters migrate between permanent temporary stands Spartina. Brachypters, because their immobility early age at first reproduction, successful morph as long conditions remain suitable in current patch host plants. Wingform planthoppers not inherited according to any simple genetic rule; there strong environmental component. Various cues acting nymphal stage trigger developmental switch determines adult wing—form. We investigated wing—form response cues, crowding plant nutrition, by raising five levels nutritionally superior inferior seedlings Percentage macroptery was density—dependent females but males. Even when raised isolation significant number males eclosed macropters. There no consistent main effect nutrition However, x interaction, suggest migration observed high densities dampened if feed hosts. The roles population dynamics behavior P. discussed.