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Abstract
Occurrence, abundance, predatory potential and residual effect of insecticides on the heteropteran predators, big-eyed bugs Geocoris punctipes (Say), G. uliginosus (Say) and the minute pirate bug, Orius insidiosus (Say) were studied in different turfgrass taxa. Evaluation of sweep and vacuum samples collected from 20 residential lawns, revealed a significant influence of grass taxa on abundance of all predatory heteropterans. None of the predatory heteropterans were affected by turfgrass density. Anthocorids increased with increasing turfgrass height and all stages of mirids were more often collected as weed density increased. Anthocorids were most abundant in St.Augustinegrass and showed a strong correlation with the abundance of chinch bugs. Male G. punctipes killed significantly more fall armyworm, Spodoptera frugiperda (J. E. Smith) neonates on bermudagrass and seashore paspalum than on zoysiagrass cultivars, while, Orius demonstrated significant predation on zoysiagrass and bermudagrass cultivars. Fall armyworm mortality was highest on Cavalier and least on Sea Isle 1 and their mortality occurred in the following order: zoysiagrass > seashore paspalum > bermudagrass in the field when different densities of Orius were released. In both pesticide assessment trials, reduced concentrations of chlorpyrifos were toxic to G. uliginosus and G. punctipes as compared to controls. Different concentrations of both spinosad and halofenozide failed to influence (P > 0.05) the survival of big-eyed bugs in tube trials for one and three days after exposure.