Curculio rubidus, GYLLENHAL, 1836

Anderson, Robert S., Keller, Oliver & Prena, Jens, 2013, Curculio rubidus Gyllenhal, 1836 (Coleoptera: Curculionidae: Curculioninae), a European Weevil New to North America, The Coleopterists Bulletin 67 (3), pp. 368-369 : 368-369

CURCULIO RUBIDUS GYLLENHAL, 1836 ( COLEOPTERA : CURCULIONIDAE : CURCULIONINAE ), A EUROPEAN WEEVIL NEW TO NORTH AMERICA

ROBERT S. ANDERSON Canadian Museum of Nature, P.O. Box 3443, Station D Ottawa, ON K1P 6P4 CANADA [e-mail]

OLIVER KELLER Department of Biological Sciences, Wichita State University, 1845 Fairmount Wichita, KS 67201, U.S.A. [e-mail]

AND

JENS PRENA 4849 Connecticut Ave. Washington, DC 20008, U.S.A. [e-mail]

In August 2012, the second author (OK) brought some recently collected weevil specimens from Michigan to the first Weevil Identification Course held at the Southwest Research Station of the American Museum of Natural History (1 – 7 August 2012) for identification. Among these specimens were three specimens of a species of Curculio L., 1758 not recognized by the first author (RSA). These specimens had the habitus of a Curculio ( Fig. 1 ), as well as the very distinctive mandibular structure and orientation. But since they were quite a bit smaller (2.9 – 3.2 mm) and were lacking any trace of femoral teeth, they could not be one of the native North American species (Gibson 1969). RSA contacted JP and, as JP was familiar with the European fauna, asked if he had any ideas about a species identity of possible European provenance. JP suggested Curculio rubidus Gyllenhal, 1836 as a possible candidate. Subsequent examination of C. rubidus specimens of European (France) provenance from the United States National Museum confirmed the identification.

Curculio rubidus is a widespread European species that is associated with Betula L. (Betulaceae) (birch) (Hoffmann 1954). The larva develops in male birch catkins (Opanasenko 1976), and adults are generally encountered on the same plants. Adults are active from May to October (Hoffmann 1954).

Identification of C. rubidus ( Figs. 2 – 3 ) in North America is quite easy. The species has the typical habitus of a Curculio, with a mottled pattern of various tan to brownish scales, a very long, slender snout, and distinct, triangular mandibles that are oriented parallel to the length of the snout and which operate in a vertical (rather than horizontal) plane. The three North American specimens vary in body length from 2.9 – 3.2 mm, whereas other North American Curculio ( Fig. 1) range from 4.2 – 13.0 mm in body length (Gibson 1969). Native North American Curculio species also possess variously developed femoral teeth (on all three sets of femora) and no native North American Curculio species is associated with Betula (Gibson 1969, 1985).

Specimens Examined. U S A: M I C H I G A N: Tuscola County, Millington, 43°17 ′ 55.69 ″ N, 83°30 ′ 23.14 ″ W, 3 – 11.viii.2011, Coll. O. Keller, Malaise trap in deciduous forest (1♀), same data except 11.viii.2011, sweeping (1 ♂). Sanilac County, Port Sanilac 43°27 ′ 14.90 ″ N, 82°33 ′ 17.38 ″ W, 24.viii.2010, Coll. O. Keller, on birch tree (1♀). Specimens are deposited in the Canadian Museum of Nature and United States National Museum.

Figures

Figs. 1–3. 1) Curculio strictus Casey, Ottawa, ON, Canada; 2) Curculio rubidus, lateral habitus (enlarged), Millington, MI, USA; 3) C. rubidus, lateral habitus. Scale bar applies to Figs. 1 and 3.