Characterization of the arthropod community in Nebraska switchgrass (Panicum virgatum L.)

Switchgrass (Panicum virgatum L.) is a perennial warm-season grass, native to Nebraska and the North American Great Plains. Recently, switchgrass has received increased attention due to its potential as a biomass energy crop. This expansion in switchgrass acreage has increased the likelihood of pest emergence. Unfortunately, little is known about the arthropod community affecting switchgrass grown under managed or minimally managed conditions. This information is essential for characterizing the insects and mites associated with switchgrass and developing appropriate management strategies for potential pests. Therefore, the objectives of this research were to identify the arthropods associated with switchgrass in Nebraska, document the seasonal abundance of selected pests and beneficial arthropods, and determine the influence of switchgrass stand age on the arthropod community. In 2007 and 2008, arthropods were sampled every two weeks from May through October using four collection techniques: vacuum samples, soil cores, pitfall traps, and yellow sticky traps. Samples were collected from three and eleven year old switchgrass stands at the UNL Agricultural Research and Development Center near Mead, NE and from native switchgrass at Nine-Mile Prairie in Lancaster County, NE. Aphids, leafhoppers, chinch bugs, grasshoppers, and wireworms were the most abundant herbivores collected. Several beneficial arthropods were also collected, including ants, rove beetles, ground beetles, parasitoid wasps and spiders. This research provides important baseline information on the arthropods associated with switchgrass grown in intensive production systems. The ultimate goal is to develop effective and sustainable management strategies for the key arthropod pests affecting switchgrass plantings in Nebraska.