Ecotope Differentiation in a Guild of Sap‐Feeding Insects on the Salt Marsh Grass, Spartina Patens

Niche and habitat differentiation are studied in seven sap—feeding insects (mostly leafhoppers and planthoppers) that inhabit the salt marsh grass Spartina patens. The microhabitat niche dimension is well partitioned. Four species of sap—feeders occur primarily in the upper stratum of the grass system, while three others are abundant in and beneath the lower thatch layer. Conversely, the seasonal niche dimension is poorly partitioned and most species show similar phenologies. The elevational habitat dimension is also poorly partitioned where most of the sap—feeders occur most abundantly on patches of grass within 10 cm of mean high water level. There are sufficient differences in resource utilization along niche and habitat dimensions as well as body size to explain the coexistence of all sap—feeders but two. The niches and body sizes of Amplicephalus simplex and Aphelonema simplex are very similar. One of these species, the leafhopper, Am. simplex, is the only species that fully retains the ability to fly. Populations of the other seven species are composed mostly of flightless brachypterous wing—morphs. It is hypothesized that Am. simplex is able to coexist in the guild because it is able to efficiently colonize relatively empty (competitor—free) patches of grass created by the catastrophic effects of storm tides.