Jumping Performance in Flightless Hawaiian Grasshopper Moths (Xyloryctidae: Thyrocopa spp.)

Abstract

Saltatorial locomotion has evolved multiple times in flightless Lepidop- tera, particularly on oceanic islands and in habitats with high winds. The kinematics of this behavior are unknown but are clearly relevant to escape performance in the absence of wings. We investigated jumping in two non-sister species of bra- chypterous Hawaiian moths (genus Thyrocopa). Moths were collected from the islands of Maui and Hawaii. Lateral views of jumps were recorded on video and then digitized. Jump distances of both species averaged about ten body lengths. In males of Thyrocopa apatela, jump distance was significantly correlated with the maximum horizontal component of jump velocity. Jumping ability may become enhanced as a means of evading predators when selection for flight performance is relaxed under high-wind regimes.