Haplorhynchites aeneus (Boheman)

Young, Julia Janicki Daniel K., 2021, Survey of the Attelabidae of Wisconsin (Coleoptera: Curculionoidea), Insecta Mundi 2021 (891), pp. 1-61 : 15-17

Haplorhynchites aeneus (Boheman)

( Fig. 15–16 )

Diagnosis. Haplorhynchites aeneus can be recognized by the abundant erect pubescence, by the generally larger size, and by the black integument. It can be distinguished from other Haplorhynchites species by the dense, random punctures on the elytra. It may also be confused with Auletobius ater , but it can be distinguished by the antennae that are inserted in or just in front of the basal 1/3 of the rostrum, which is inserted near the middle of the rostrum in A. ater .

Description. Length 3.9–6.6mm. Integument black, venter and tip of rostrum with faint greenish luster. Vestiture consisting of abundant, erect setae. Head conical, with moderate punctures; interpuncture space forming irregular longitudinal ridges. Rostrum slightly arcuate, in male only 1.3× pronotal length, in female as long as head + pronotum; sides in dorsal view expanded in apical 1⁄5, width at apex about 1.25× width of frons. Antennae inserted at or just in front of basal 1/3 of rostrum. Pronotal width about 1.2× length, widest behind middle; distinctly arcuate laterally; disc with shallow, close punctures, interpuncture space shining, smooth, with coarse, erect, brown setae. Elytral length about 1.2× width, width 2.0× pronotal width; surface randomly punctured, the punctures close and deep, bearing coarse, erect setae; straie and interstriae inconspicuous. Sexual dimorphism present in length of rostrum.

Natural history. This species has been recorded from the eastern part of the US, westward to the continental divide, but is most numerous in the Midwest. It is the most common Haplorhynchites species in North America and is associated with many species in the sunflower tribe Heliantheae . Male and female adults are usually found together on uncut flower heads shortly after their appearance in July, copulation then occurs on these heads; after or during copulation the females would cut the stems below the flower heads incompletely so the heads are still attached. Eggs are found in the disc-flower bases of cut heads, and eclose in about a week. After reaching maturity the larvae leave the cut heads and enter the soil. The larvae overwinter and emerge the following July ( Hamilton 1973).

This species is generally associated with sunflowers ( Helianthus Linnaeus spp. ), including woodland sunflower ( Helianthus divaricatus Linnaeus ), sawtooth sunflower ( Helianthus grosseserratus Martens ), common sunflower ( Helianthus annuus Linnaeus ), stiff sunflower ( Helianthus pauciflorus Nuttall ), and few-leaf sunflower ( Helianthus occidentalis Riddell ). It has also been recorded from rosinweeds ( Silphium Linnaeus spp. ), including compassplant ( Silphium laciniatum Linnaeus ), wholelead rosinweed ( Silphium integrifolium Michaux ) and prairie rosinweed ( Silphium terebinthinaceum Jacquin ), as well as scruf pea ( Psoralea Linnaeus spp. ), oxeye ( Heliopsis Persoon spp. ), tickseed ( Coreopsis Linnaeus spp. ), and prairie goldenrod ( Solidago ptarmicoides (Torrey & A. Gray) B. Boivin ).

In Wisconsin, they have been found on disc flowers of stiff sunflower, few-leaf sunflower, and prairie goldenrod, as well as swept from blazing star ( Liatris Schreber spp. ), rosinweeds ( Silphium spp. ), bergamot ( Monarda Linnaeus spp. ) and dogbane ( Apocynum Linnaeus spp. ). Hamilton (1973) provided detailed information on its biology.

Phenology. In Wisconsin, adults have been collected from July to September, with a peak in July and August.

Collecting methods. Thirty-two Wisconsin specimens were examined during this study from four counties. This species can be readily collected by hand from disc flowers of sunflower species. It can also be collected by sweeping prairies where its plant associations are present.

Distribution. United States. AL, AR, CA, CO, FL, GA, IA, IL, IN, KS, MA, MD, MI, MN, MO, MS, MT, NC, ND, NE, NJ, NM, NY, OH, OK, PA, SC, SD, TN, TX, VA, WI, WV. Canada. MB, SK.

Wisconsin county records. This species has previously been recorded from Wisconsin ( Blatchley and Leng 1916; O’Brien and Wibmer 1982; Downie and Arnett 1996). Burnett, Grant, Kenosha, Milwaukee.

Figures

Figures 15–16. Haplorhynchites aeneus (Boheman), teneral specimen. 15) Habitus, dorsal view. 16) Habitus, lateral view.