Arthropods as bioindicators in agroecosystems of Jiang Han Plain, Qianjiang City, Hubei China

Using sweeping nets and pitfall traps, arthropods on the soil surface and o n vegetation were periodically surveyed in two villages on the Jiang Han Pl ain from April to September 1994. Statistical analysis of the resulting dat a delineated groups of bioindicators on vegetation and on the grounds that represent components of formulas for evaluating environmental quality in ag roecosystems. These groups are (1) Coccinellidae and Chrysopidae (seasonall y migrating predators factor); (2) Braconidae and Chalcidoidea (parasitic i nsects factor); (3) Araneae and Mantodea on vegetation and Araneae, Carabid ae, Opiliones and Nitidulidae on the ground (carnivorous arthropods factor) ; and (4) Formicidae, Isopoda, and Chilopoda (soil-dwelling arthropods fact or). The following resource pools were identified for the different model a rthropods: woodlots for Araneae and Mantodea; field margins for Chrysopidae and Coccinellidae; hedgerows for Braconidae and Chalcidoidea; and low-inpu t cropfields on the floodplains for epigeic carnivorous arthropods. Compari son of these insect groups in different rural landscape units demonstrated the importance of a mosaic rural landscape, including woodlots, rationally designed field margins, and cropland, for creating an ecologically favorabl e agricultural environment.