Gonotropis dorsalis (Thunberg)

Janicki, Julia & Young, Daniel K., 2017, Nemonychidae and Anthribidae of Wisconsin (Coleoptera: Curculionoidea), Insecta Mundi 2017 (579), pp. 1-36 : 23

Gonotropis dorsalis (Thunberg)

(Fig. 35–36)

Anthribus dorsalis Thunberg 1796: 146 .

Gonotropis gibbosus LeConte 1876: 394 .

Tropideres dorsalis (Thunberg) ; Wolfrum 1929: 55.

Description. Length 4.5–6.0mm (head excluded). Vestiture on pronotum dense, sparser laterally, white apically and laterally, forming brownish, triangular, median spot; vestiture on elytral base forming a large spot of light-brown to white setae extending laterally to 5 th interstria, remainder of elytra with light to dark brown setae and scattered white setae. Rostrum covered with dense, white setae. Frons flattened, without carinae; surface sculpture concealed by dense white setae except at lateral and apical angles. Pronotal width 1.5–1.6X length, widest at base; sides angulate basally, straight, and then strongly converging to narrowly rounded apex; base broadly emarginate, transverse carina antebasal, acute, strongly elevated, angulate medially towards scutellum, lateral carinae acute, strongly elevated; pronotal surface dark, dull, setaceous, densely reticulate, with deep punctures; pronotal disc distinctly impressed medially, less distinctly impressed basally. Elytral length 1.3X width, broadly rounded apically; striae with very deep, small punctures in regular rows; interstriae 3, 5 and 7 distinctly elevated, broadly tuberculate, base of 3 rd interstria with one prominent elevation. Pygidium vertical, broadly rounded apically in both sexes.

Diagnosis. Gonotropis dorsalis can be recognized by the prominent elevations on the elytral bases, white frons and rostrum, large patch of whitish-yellow setae that is almost an inverse heart shape basally on the elytra, and by the patch of triangular brown setae basomedially on the pronotum.

Natural history. This species has been recorded from “dead hemlock”. It was also recorded on dry branches of oak ( Quercus spp. ) and birch ( Betula spp. ) in Europe ( Pierce 1930), as well as on poplar ( Populus spp. ) ( Downie and Arnett 1996). Valentine (1998) elaborated on one specimen from Madison, Wisconsin with a long label: “Hybrid poplar, Madison Wis. Beetle issued from callous around a canker. Aug. 1952 Dr. Waterman, Pathologist New Haven, Conn. Sent by J. V. Schaffner, Jr.”

Phenology. No additional data for Wisconsin.

Collecting methods. In Wisconsin, two specimens examined represent a NEW STATE RECORD. This series of specimens had meager label data associated with them: “before Oct 1897 ”, without county or phenological data.