Movement in a zaprochiline katydid (Orthoptera: Tettigoniidae): sex-specific response to food plant distribution

Movement in relation to local food levels was compared between the sexes of the zaprochiline katydid Kawanaphila nartee Rentz. Adults of both sexes were marked, and their departure rates were estimated (1) early in the season for two plots having high vs. low food density and (2) throughout the season for a single plot with changing food levels. Based on the between-plot comparison, movement of males was independent of food density, whereas females were less likely to leave the rich patch than the poor one. The within-plot comparisons revealed that, despite large changes in food levels, male departure rates did not vary over the season. Females showed increased movement over the season and by the end of the study had a departure rate similar to that of males.