Allandrus bifasciatus LeConte, 1876

Janicki, Julia & Young, Daniel K., 2017, Nemonychidae and Anthribidae of Wisconsin (Coleoptera: Curculionoidea), Insecta Mundi 2017 (579), pp. 1-36 : 10

Allandrus bifasciatus LeConte

(Fig. 9–10)

Allandrus bifasciatus LeConte 1876: 396 .

Description. Length (head excluded) 2.6–3.5 mm. Body elongate. Integument black; elytra reddish to dark brown. Vestiture consisting of a mixture of white, light brown, and dark brown to black setae; elytra with predominantly dark setae with white setae in scattered small patches. Rostrum of male with keellike, sharply elevated longitudinal carina, that of female with carina evident but not elevated; surface with dense, deep punctures. Frons convex and broad, with dense, deep punctures. Antennae of male 2.0X longer than those of female. Eyes entire, slightly oval. Pronotum about as wide as long, widest at lateral extension of transverse carina, transverse carina antebasal, strongly, sharply elevated, rather strongly emarginate; disc convex, surface even and very weakly impressed before middle, with dense, deep punctures that are internally reticulate. Elytral length 1.6X width, length 2.0X pronotal length; surface of disc generally nearly even, with obscure basal swellings; striae deeply impressed, with moderate punctures; interstriae flat, densely and minutely punctate. Pretarsus with each claw cleft, inner tooth minute. Sexual dimorphism present in tibiae: prothoracic tibiae of male strongly curved and bent.

Diagnosis. Allandrus bifasciatus can be distinguished from A. brevicornis by the suprascrobal carina that surpasses the antennal scrobe, nearly even elytral surface with obscure basal swellings, the long antennae, high median keel or carina on the rostrum, and by the strongly curved and bent prothoracic tibiae in the males. It can be distinguished from A. populi by the presence of a small, medial tooth on each pretarsal claw.

Natural history. This species is a specialist on Tilia species ( Blatchley and Leng 1916; Majka et al. 2007), including American basswood ( Tilia americana ).

Phenology. In Wisconsin, adults have been collected July – September.

Collecting methods. In Wisconsin, 49 specimens were examined during this study from 11 counties. They can be readily collected by beating live or dead branches of American basswood ( Tilia americana ).