Synolabus nigripes (LeConte)

Young, Julia Janicki Daniel K., 2021, Survey of the Attelabidae of Wisconsin (Coleoptera: Curculionoidea), Insecta Mundi 2021 (891), pp. 1-61 : 6-7

Synolabus nigripes (LeConte)

( Fig. 3–4 )

Diagnosis. Synolabus nigripes can be recognized by the red dorsum and by the prothoracic femora that are toothed ventrally. It can be distinguished from S. bipustulatus by the red dorsum and by the rostrum that is only a little shorter than the pronotum and that is constricted at the antennal insertion. It can be distinguished from Homeolabus analis by the generally smaller size, by the red thoracic sterna (black in H. analis ), and by the submental area in males that has a conspicuous median tooth and in females a swelling (a pair of projecting acuminate spines in H. analis ).

Description. Length 3.5–4.5mm. Body robust. Integument bright red to black; elytra, thorax, base of head, prothoracic sternum, and abdomen bright red; legs, rostrum and antennae black. Head arcuate laterally from base to eyes; surface smooth, with few very small, widely separated, shallow, minute punctures and with two deeply impressed arcuate grooves along each eye; median area impressed from antennal insertion to above upper level of eyes. Rostrum a little shorter than head, constricted at antennal insertion; surface densely punctured, rugose; submental area in males with conspicuous median tooth, in females with swelling. Antennae inserted dorsolaterally near base of rostrum. Pronotum width about 1.5× length, widest at base; arcuate laterally, converging to recurved apex; disc evenly convex, with minute, impressed punctures, interpuncture space smooth and shining. Elytra width at base about 1.3–1.4× pronotal width, broadly rounded apically; striae not impressed, with large, shallowly impressed punctures in regular rows; interstriae about 3.0× strial width. Prothoracic femora of male armed with 1–2 blunt spine-like projections, of female unarmed or armed with 1 peg- like projection.

Natural history. This species has been recorded on winged sumac ( Rhus copallina Linnaeus ), poison ivy ( Toxicodendron radicans (Linnaeus) Kuntze ) and related plants. In Wisconsin, this species has been recorded feeding on leaves of staghorn sumac ( Rhus typhina Linnaeus ). Specimens have also been reported from little bluestem ( Schizachyrium scoparium (Michaux) Nash ), sideoats grama ( Bouteloua curtipendula (Michaux) Torrey ) and prairie dropseed ( Sporobolus heterolepis Gray ). Synolabus nigripes is most often collected in prairies (dry, dry hill, sand, bluff) and savannas, as well as in oak barrens.

Phenology. In Wisconsin, adults have been collected in May, June, July, August and October.

Collecting methods. The 50 Wisconsin specimens examined during this study from 12 counties represent a new state record (Appendix 1). A series of specimens was collected on sumac ( Rhus Linnaeus spp. ), others were on flowers in general, some were collected by sweeping and one was collected in a Malaise trap.

Distribution. United States. AR, AZ, CO, CT, DC, DE, FL, GA, IA, IL, IN, KS, MA, MD, MN, MO, NC, NE, NJ, NM, NY, OH, PA, RI, SC, TN, TX, VA, WI, WV.

Wisconsin county records. Burnett, Crawford, Dane, Dunn, Grant, Iowa, La Crosse, Manitowoc, Monroe, Polk, Sauk, Vernon.

Figures

Figures 3–4. Synolabus nigripes (LeConte). 3) Habitus, dorsal view. 4) Habitus, lateral view.