Submitted to: Annals of the Entomological Society of America
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 5/1/2001
Publication Date: 7/1/2000
Citation: Horton, D.R., Lewis, T.M. 2000. Seasonal distribution of Anthocoris spp. and Deraeocoris brevis (Uhler) in some orchard and non-orchard habitats of central Washington (Heteroptera: Anthocoridae, Miridae). Annals of the Entomological Society of America. 93:476-485. Interpretive Summary: Predatory insects in the family Anthocoridae and Miridae are effective biological controls against pests occurring in pear when the predators are present. However, their presence in orchards is highly irregular apparently due in part to the availability of suitable prey outside of the orchard. We monitored use of certain specific habitats adjacent to orchards to determine use of these habitats by these predators. Predators were common on several shrub and tree species in these habitats, notably willow, cottonwood, oak, alder, aspen, poplar, and bitterbrush. There were distinct seasonal changes in use of plant species, with willow being important very early in spring, and other species (oak, cottonwood, poplar) becoming important in mid-summer and late-summer. We conclude that non-orchard habitats often support large populations of these predators, and suggest that pear growers in the Pacific northwest could benefit by making use of these sources (e.g., by encouraging growth of native plants adjacent to orchards or by planting specific types of windbreaks).
Technical Abstract: Seasonal use of non-orchard habitats by certain anthocorid and mirid predators is described for areas adjacent to the fruit growing regions of Yakima, WA. The predators were found on several tree and shrub species in these habitats, especially willow, cottonwood, oak, alder, aspen, poplar, and bitterbrush. Anthocoris whitei was found almost exclusively on antelope bitterbrush in close association with an unidentified psyllid, whereas other species in this genus were more generalized. Adult and immature A. antevolens were common on oak, cottonwood, and poplar. A. tomentosus was comparatively uncommon on these species, but was more abundant than A. antevolens on the neighboring willows; immatures of A. tomentosus were never recovered from oak. Adult and immature Deraeocoris brevis were collected from species not shown to support Anthocoris spp., suggesting that the mirid is more generalized than the anthocorids. The anthocorids were very rare in apple orchards, whereas D. brevis was common in apple. A. tomentosus and A. antevolens congregated on willow catkins in March and moved onto summer hosts (oak, alder, poplar) in May and June. Overwintering A. antevolens and D. brevis were more broadly distributed among plant species than A. tomentosus or A. whitei.