Eurymycter fasciatus (Olivier)

Janicki, Julia & Young, Daniel K., 2017, Nemonychidae and Anthribidae of Wisconsin (Coleoptera: Curculionoidea), Insecta Mundi 2017 (579), pp. 1-36 : 24-25

Eurymycter fasciatus (Olivier)

( Fig. 37–38 )

Macrocephalus fasciatus Olivier 1795: 9 .

Eurymycter bicarinatus Pierce 1930: 17 .

Tropideres fasciatus (Olivier) ; Valentine 1960: 70.

Eurymycter fasciatus (Olivier) ; Valentine 1998: 275.

Description. Length 5.8–7.5 mm (head excluded). Integument dark brown. Vestiture of pronotum consisting of small, light brown setae, with scattered, small, white or yellow patches; metathoracic tibial setae each forming two, pale narrow median bands, or setae on tibial apex brown, spotted with white. Rostrum prolonged, flattened, with three carinae, two lateral carinae distinctly elevated, medial carina less distinctly elevated; rostral surface concealed by dense, white, recumbent setae. Frons evenly convex; median longitudinal groove not evident; surface concealed by dense, white, recumbent setae. Pronotal width 1.3X length, widest behind middle; sides angulate basally, converging toward broadly rounded apex, broadly emarginate basally; transverse carina antebasal, strongly elevated; lateral carinae acute, strongly elevated; surface very irregular, with median, narrow, deeply impressed W-shaped groove medially; disc with various weak elevations and distinct, strong punctures or small impressions laterally, surface shining, with dense, minute punctures. Elytral length 1.4X width, broadly rounded apically; striae indistinct, with rather small, deep punctures, these larger and much deeper basally; interstriae 3, 5 and 7 weakly elevated, the elevations smooth on summit, base of 3 rd interstria slightly elevated. Abdomen with venter covered with white setae, sometimes with scattered, small brown spots laterally. Pygidium vertical, narrowly rounded apically in both sexes.

Diagnosis. Eurymycter fasciatus can be easily distinguished from E. tricarinatus by the solid white abdominal pubescence that may or may not have brown lateral spots (as opposed to the brown abdomen in E. tricarinatus ). It can also be distinguished by the elevated interstriae 3, 5, and 7, and by the metathoracic tibiae that each have two, narrow median bands (each metathoracic tibia with one ring in E. tricarinatus ).

Natural history. This species is generally associated with fungi on woody plants and can often be found under bark of decaying wood. More specifically, both adults and larvae are recorded to feed on pyrenomycete fungi growing on birch ( Betula spp. ) ( Majka et al. 2007). It has also been recorded from sassafras (Sassafras albidum).

Phenology. In Wisconsin, adults have been recorded in June and July.

Collecting methods. The three Wisconsin specimens examined during this study from two counties represent a NEW STATE RECORD. This species is most commonly collected in Malaise traps in hardwood forests or oak/pine barrens.

Figures

Figures 37–38. Eurymycter fasciatus (Olivier). 37) Habitus, lateral view. 38) Habitus, dorsal view. Figures 39–40. Eurymycter tricarinatus Pierce. 39) Habitus, lateral view. 40) Habitus, dorsal view.