Soybean cultural practices: effects on populations of geocorids, nabids, and other soybean arthropods

Arthropods were monitored in soybean, Glycine max L. Merrill, of early-, medium-, and late-maturity groups planted from April through July in several row spacings at four locations in Mississippi for 1 to 3 years. Geocorid, nabid, and spider populations gradually increased during the summer, but lady beetle populations peaked in midseason. Predator populations were not strongly affected by the three cultural practices: Geocorid, nabid, and spider populations (but not lady beetles) were higher in late-planted than in early-planted soybean; nabid populations (but not goecorids, lady beeltes, and spiders) were higher in late-maturing than in early-maturing cultivars; and goecorid and spider populations (but not nabids and lady beetles) were higher in narrow- than in wide-row soybean.