Arthropod predation of black grass bugs (Hemiptera: Miridae) in Utah ranges

Abstract

The predation by selected arthropod predators on immature and adult black grass bugs (BGB), Labops hesperius and Irbisia brachycera, on Utah ranges was investigated. Adult Nabis alternatus was found to be the most important predator of BGB; this species is particularly abundant in early spring and was observed preying on BGB both in the field and in laboratory feeding tests. Immature nabids consumed the bugs but preyed mostly on leafhoppers, smaller plant bug nymphs, and other immature nabids. Nabis vanduzeei showed potential as a predator of adult BGB in the laboratory feeding tests. Spiders were important predators of BGB. Based on predation of BGB in field and laboratory studies, the spiders observed were ranked as follows from greatest to least importance as predators: Xysticus cunctator, Misumenops lepidus, Tibellus sp. (Thomisidae), Castianeira sp. (Clubionidae), and Tetragnatha sp. (Araneidae). Spiders attacked any prey of a size similar to themselves, but they also preyed on beneficial arthropods, including nabids and other spiders.