Biology and Nymphal Stages of Deraeocoris nebulosus (Hemiptera: Miridae), a Predator of Arthropod Pests on Ornamentals

Abstract

Nymphal stages of the mirid Deraeocoris nebulosus (Uhler) are described and figured and results of field and laboratory studies on biology in Pennsylvania during 1973–74 are reported. This predator was associated with mites, aphids, scales, whiteflies, psyllids, and lace bugs on more than 50 species of ornamental trees and shrubs. D. nebulosus had 3 generations in an ornamental planting in central Pennsylvania and utilized a series of host plants and prey species during the season. Five weekly samples from 4 branches on each of 2 white oaks infested with oak lace bug, Corythucha arcuata (Say), showed that nebulosus can develop large populations in the second generation. In the laboratory, average duration of the 5 nymphal instars was 2.7, 3.2, 4.3, 4.6, and 5.0 days, respectively, with the nymphal period averaging 19.8 days. An average of 107.6 oak lace bug nymphs was consumed during nymphal development. Consumption of lace bug nymphs increased with increasing prey density, suggesting that nebulosus could be important in suppressing populations of lace bugs and other pests on ornamentals.