Biology of the insidious flower bug Orius insidiosus (Say) (Heteroptera: Anthocodoridae)

The overwintering habitats of Orius insidiosus (Say), timing of diapause in field populations, and seasonal dynamics in selected crop and non-crop habitats were evaluated during 1992 and 1993 in two locations, one in southwestern and the other in central Arkansas. Each location covered three square miles of various habitats. In early spring, females were found primarily on hairy vetch, crimson clover, and hairy buttercup. During that time, these weeds were flowering and infested with high populations of thrips. During late spring and summer, populations increased in association with increases in thrips populations and flowering of corn, grain sorghum, cotton, and soybean. In the fall, populations declined sharply and became widely dispersed. Diapause status was determined by dissection. In the winter, females collected in 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 winter vegetation, primarily grasses including wheat.; The functional response of O. insidiosus and the extent of prey switching between Frankliniella fusca (Hinds) and Heliothis virescens (F.) by O. insidiosus in early season cotton were evaluated. The test was conducted in the laboratory using four leaf stage cotton for 24 hr. at 22 {dollar}pm{dollar} 1{dollar}spcirc{dollar}C and 14:10 (L:D) photoperiod. Five day old O. insidiosus females were starved for ten days were used in the test. Twenty-two prey combinations were used in the evaluation of O. insidiosus. The possible adaptation of the predator to one host type was evaluated by comparing predation responses of two populations of O. insidiosus: one reared on H. virescens and the other on F. fusca. There were no significant differences in the extent of predation of either prey type caused by previous diet. Orius insidiosus expressed a type II functional response. The total number of prey consumed was affected by prey density available, as was thrips predation in the absence of alternate prey. On the other hand, the number of H. virescens eggs or larvae consumed was not affected by the number of prey available.; A sampling method was evaluated for sampling thrips in early season cotton. The technique, termed the "pan method", involves dislodgment of insects off plants into a wire-covered pan. The method was evaluated in two locations in Arkansas and was compared to the plant washing method. The same population trends were obtained from both sampling methods. A higher number was generally recovered using the plant washing method, although values were not significantly different on all sampling dates. The pan method recovered an average of 45% of the thrips taken in washing samples. The pan method is practical and can be adapted by field scouts for monitoring thrips populations in early season cotton.