Submitted to: Proceedings of the Entomological Society of Washington
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 7/10/2015
Publication Date: 9/28/2015
Citation: Lewis, T.M., Horton, D.R., Lattin, J.D. 2015. First nearctic records for Orius (Dimorphella) sibiricus Wagner (Hemiptera: Heteroptera: Anthocoridae), a Eurasian steppe inhabitant. Proceedings of the Entomological Society of Washington. 117(3):389-399.
Interpretive Summary: The minute pirate bugs (Orius) are primary sources of biological control in vegetable and other row crops worldwide. Scientists with USDA-ARS, Yakima Agricultural Research Laboratory, Wapato, WA and Oregon State University, OR, discovered a Eurasian species of minute pirate bug in northwestern North America which has been consistently misidentified as a native species common in North American agricultural crops. Body traits which allow correct separation of the two species are listed, and updated distributions for both species in North America are provided. These results will help with the correct identification of minute pirate bugs found in certain vegetable crop systems of western North America, leading to more efficient use of these species in biological control efforts.
Technical Abstract: Orius sibiricus Wagner, a dark-colored minute pirate bug widespread in the Eurasian Steppe, is recorded from sites near the Yukon River in Yukon, Canada. This species is distinguished from the melanic phenotype of Orius diespeter Herring by the more deeply and uniformly punctured dorsum, the subangular anterolateral angles of the pronotum of the female, the lack of denticles on the forefemora of the male, the entirely dark embolium, and the shape of the paramere. Collection sites for O. sibiricus in Yukon are in ecoregions that contain sun-warmed steppe in or near East Beringia. The species has also been collected in eastern Siberia from steppe sites within the boundaries of West Beringia. Specimens of O. sibiricus from East Beringia and West Beringia have very similar genitalic structures. Orius sibiricus has been collected from the plant genera Artemisia, Caragana and Spiraea, as well as from unidentified herbaceous vegetation. The geographical distribution of O. sibiricus suggests a relatively recent dispersal across the Bering Land Bridge.