Size and shape variation of Hypsipyla grandella Zeller (Lepidoptera: Pyralidae) in two hosts: A morphometric approach

Abstract

The mahogany shoot borer (Hypsipyla grandella) attacks different Meliaceae species and impedes its plantation. Its biology is poorly known, but some results show a preference for Cedrela odorata L. over Swietenia macrophylla King, which could generate intraspecific variations. We studied the effect of these hosts on H. grandella right-forewing size and shape variation, using a geometric morphometry approach. We collected larvae in plantations of each host, rose them in seedlings of the same original host and set 13 landmarks on 63 right-forewings. Sexual-shape dimorphism was present and the right-forewings of individuals collected in C. odorata were larger. Removing the allometric effect and comparing magnitude and direction in the plastic responses of the sexual-shape dimorphism, we only found differences in the direction. Differences in the right-forewing shape within sexes were present when comparing hosts and removing the allometric effects. Only the right-forewing of males differs between hosts in terms of shape. The differences found could influence the species' flying system. Individuals with the larger right-forewings could be more frequent in C. odorata plated areas, with an increased ability for long-distance flights, which is undesired in integrated pest management systems.