NEW SYNONYMY OF RHADIURGUS VARIABILIS (ZETTERSTEDT) (DIPTERA: ASILIDAE) WITH NOTES ON MORPHOLOGY, NATURAL HISTORY, AND GEOGRAPHICAL VARIATION

• Published in: The Canadian Entomologist
• Main Author: Cannings, Robert A.
• Format: Article in Journal/Newspaper
• Language: English
• Published: Cambridge University Press (CUP) 1993
• Subjects: Insect Science; Molecular Biology; Physiology; Ecology, Evolution, Behavior and Systematics; Structural Biology; Yukon; Alaska; Siberia
• Online Access: http://dx.doi.org/10.4039/ent125337-2; https://www.cambridge.org/core/services/aop-cambridge-core/content/view/S0008347X00008853

Abstract Rhadiurgus variabilis (Zetterstedt 1838), a robber fly described from Europe, and Nigrasilus nitidifacies Hine 1908, described from North America, are newly synonymized. Lectotypes are designated for Asilus variabilis Zetterstedt and N . nitidifacies Hine. Some new descriptive material, including measurements and colour data, is given for five geographical regions: Europe, Eastern Siberia, Alaska/Yukon, Western Cordillera, and Boreal North America. Illustrations of male and female genitalia are presented. The species’ range is clarified and ecological data are summarized. Rhadiurgus variabilis inhabits northern and mountain forests from Scotland eastward to Labrador; it is one of the world’s most northerly ranging robber flies. Variation in the species includes an increasing proportion of dark body setae in individuals from Eurasia eastward through North America.