The effects of 5 m wide, managed fallow vegetation field borders on arthropods in cotton and soybean crops were investigated with sweep net sampling, visual inspections and pitfall traps. Field borders enhanced the populations of some beneficial insects in both cotton and soybeans. Thrips were more abundant in cotton fields with borders. Bollworm damage, number of bollworm eggs and larvae on terminals in cotton were similar for both border treatments. Bean leaf beetles in soybeans were more numerous in fields without borders in 1999. Field border presence did not increase the abundance of any pest species in soybeans in 1999.