SPECIES COMPOSITION, ABUNDANCE AND DIVERSITY OF HEMIPTERANS ASSOCIATED WITH Sporobolus pyramidalis (POACEAE)

ABSTRACT

Sporobolus pyramidalis (Poaceae), commonly known as Giant Rat’s Tail grass, is an indigenous grass in Africa that was introduced into Australia and several countries to supplement food for livestock and protect soil covers from erosion. In the introduced range S. pyramidalis has become invasive as it has escaped the selection pressure from natural enemies. Here, this study was focused on profiling the community of Hemipterans that utilise S. pyramidalis as a plant host. Using sweep net, twenty samples were collected during the month of September. From these sampling events, the species composition, abundance and diversity of insects species in the order Hemiptera that were associated with the grass were computed using PAST™. A total of 665 individuals categorised into 9 morphospecies were encountered. Species rarefraction curve was used to compute the species accumulation which revealed that at the end of the sampling events the curve did not reach its asymptote. The finding suggest that more Hemipteran species associated with S. pyramidalis still remain unaccounted for. The non-parametric estimates from Chao2; first and second order Jackknife gave a 100%, 90.5% & 82.9% inventory completeness which on the average suggest that 91% of the Hemipterans associated with S. pyramidalis were accounted for in this study. The implication of these findings is that more species are likely to be found on S. pyramidalis than had been recorded if sampling was extended. This survey is relevant to the search for promising natural enemies on S. pyramidalis