Arthropod biodiversity in an intensively managed agricultural landscape

Arthropod communities were sampled during the summer of 2006 and will be sampled during 2007 in an agricultural landscape of northwestern Ohio to determine patterns of arthropod biodiversity in agroecosystems as well as in noncrop habitats.  The dominant agroecosystems in this region are corn, soybean, wheat, and alfalfa agroecosystems.  Noncrop habitats include forests, meadows, filter strips, fencerows, and hedgerows in close proximity to the agroecosystems.  During 2006, arthropods were collected from edges of soybean agroecosystems using a 38 cm sweep net from mid-July through mid-September.  These soybean agroecosystems differed in terms of the noncrop habitats present along one edge; approximately half of the agroecosystems had a forest habitat on one edge, and half had a herbaceous habitat on one edge.  Although no significant differences were observed between the two types of soybean-noncrop habitat combinations in the 2006 season, type of edge did tend to cause numerical increases of certain phytophagous arthropod species, such as the bean leaf beetle, Cerotoma trifurcata (Coleoptera: Chrysomelidae), as well as predators such as the multicolored Asian lady beetle, Harmonia axyridis (Coleoptera: Coccinellidae), the insidious flower bug, Orius insidiosus (Hemiptera: Anthocoridae), and spiders (Araneae).  Parasitoids did not appear to follow any trends in abundance related to the type of edge habitat present.  Families of parasitic Hymenoptera collected included Braconidae, Ichneumonidae, Eulophidae, Encyrtidae, and Pteromalidae.  Tachinidae (Diptera) were also collected during 2006.  Arthropods will be sampled in 2007 from edges of corn, soybean, wheat, and alfalfa agroecosystems, as well as in the noncrop habitats using sweep nets, pan traps, insect vacuums, black light traps, and Malaise traps.  In addition, selected larval Lepidoptera will be collected from agroecosystems and reared in the laboratory to determine the parasitoid assemblages present.