Seasonal distribution and overwintering of Orius insidiosus (Say) in Arkansas

The overwintering and seasonal habitats of Orius insidiosus (Say), timing of diapause in field populations, and seasonal population dynamics in selected crop and non-crop habitats were evaluated during 1992 and 1993 at two locations, one on southwestern and the other in central Arkansas. Each location consisted of three square miles (approximate to 7.77 km(2)) of various habitats. Diapause status was determined by dissection. In early spring, females were found primarily on hairy vetch, crimson clover, and hairy buttercup. During that time, these weeds were flowering and were infested with high populations of thrips. During late spring and summer, populations of O. insidiosus increased in association with increasing thrips populations and flowering of corn, grain sorghum, cotton, and soybean. In the fall, population densities declined sharply and became widely dispersed. In the winter, females collected from both locations were in reproductive diapause from early November until mid-March. No males were recovered during the winter or early spring. Females in reproductive diapause were found to overwinter in vegetation, primarily grasses including wheat.