Grasshopper (Orthoptera: Acrididae) - Plant-environmental interactions in relation to zonation on an Atlantic coast barrier island

Distribution patterns of five grasshopper species (Orthoptera: Acrididae) were related to microtopography, plant zonation, and diet preference on a Virginia barrier island. Trimerotropis maritima Harris occurred on the landward side of incipient foredunes dominated by Ammophilia breviligulata Fernald (Poaceae), a C₃-grass. Psinidia fenestralis Serville occurred primarily on and adjacent to older dunes dominated by Spartina patens (Aiton) Muhlenberg (Poaceae), a C₄-grass. Melanoplus bivitattus Say, Melanoplus femurrubrum De Geer, and Melanoplus differentialis Thomas were more widely distributed than the other two species but were most common in wet swales dominated by S. patens and the shrub seedlings, Myrica cerifera L. (Myricaceae) and Baccharis halimifolia L. (Asteraceae). Laboratory feeding preference experiments indicated a strong influence of host plants on grasshopper distribution patterns. The diet specialists, T. maritima and P. fenestralis, were limited to the distribution of their host plant species, whereas the Melanoplus congeners were generalists in diet and in distribution. Although distribution patterns were related to host plant specificity, microtopography was important to the small-scale distribution of all five species within the distribution range of host plants. The preference of M. differentialis for Myrica cerifera foliage may affect shrub establishment in the grass-dominated swales.