Mordellistena virginica Steury and Steiner, 2020

Steury, Brent W. & Steiner, Warren E., 2020, Descriptions of Four New Species of Tumbling Flower Beetles (Coleoptera: Mordellidae) from Eastern North America, The Coleopterists Bulletin 74 (4), pp. 699-709 : 704-706

Mordellistena virginica Steury and Steiner , new species

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( Figs. 7A–C )

Type Material. Holotype. Male ( USNM), labeled “ Virginia, Fairfax Co., GWMP, Great Falls Park, swamp, Malaise trap, 1–15 July 2009, D. Smith & B. Steury. ” Paratypes (n = 20). One paratype, female ( USNM), same data but “21 July–17 August”. Additional paratypes, male ( GWMP), all labeled “ Virginia , Fairfax Co., GWMP ” and “ Turkey Run Park , River Trail, Malaise trap, 31 July–17 August 2009 , D. Smith & B. Steury ” (n = 3); same data but “ 22 June–6 July 2006 ” (n = 1); “ 1–15 July 2009 ” (n = 1); “ 18 August–4 September 2009 ” (n = 1); “Great Falls Park, swamp, Malaise trap, 19–30 June 2009, D. Smith & B. Steury ” (n = 2), same data but “ 1–15 June 2009 ” (n = 1). Additional paratypes, female ( GWMP), all labeled “ Virginia , Fairfax Co., GWMP ” and “ Turkey Run Park, ravine, 22 June–6 July 2006 ” (n = 1) ; same data but “ 22 June–6 July 2006 ” (n = 1); “ 1–15 July 2009 ” (n = 1); “ 31 July–17 August 2009 ” (n = 1); “ Turkey Run Park , powerline, Malaise trap, 1–17 June 2019 , B. Steury ” (n = 1); “ Great Falls Park, swamp, Malaise trap, 1–15 July 2009 , D. Smith & B. Steury” (n = 3); same data but “ 19–30 June 2009 ” (n = 1); “ Dyke Marsh Wildlife Preserve , Malaise trap, forest, 24 June–7 July 1998, E. Barrows ” (n = 1) .

Description. Holotype, male. Body length 3.9 mm to tip of elytra, 4.5 mm to tip of pygidium. Dorsal habitus robust, head black, labrum yellowish, pronotum black with rufous edging on base of midbasal lobe and basal corners, elytra rufous. Ventral habitus black with rufous edge basally on all abdominal ventrites and metaventrite. Front and middle legs yellowish, hind legs pale brown. Pygidium stout, concolorous with elytra, tipped with stout black setae, 2.4× length of hypopygidium. Pubescence dorsally and ventrally recumbent, pale, slightly shorter on head and pronotum than on elytra. Eyes truncated (slightly emarginated) behind antennal sockets, with many short, erect hairs, temple present, very narrow, in dorsal half only. Antennae ( Fig. 7C ) reaching to near middle of elytra, antennomeres 1–4 pale, yellowish, with appressed setae, 5–11 dark brown, velvety pubescent, with a few longer setae at apex of each antennomere, antennomeres 3 and 4 the shortest and subequal, 1 and 2 subequal, 5 longer than 2–4 combined, 5–11 subequal in length. Terminal maxillary palpomeres yellow, scalene, the lateral margin the longest. Pronotum broadest just before the base, midbasal lobe convex, lateral margin straight. Scutellar shield small and triangular, apex somewhat rounded. Elytra together 2.2 times as long as broad, broadest at base, gradually narrowing apically, narrower at base than pronotum. Legs: Metatibia with two tibial spines, the outer one-half the length of the inner one; 3 metatibial ridges with a few black spinules anterior to the last ridge, 4 ridges on metatarsomere 1, two on metatarsomere 2, and one on metatarsomere 3 with three black spinules anterior to the ridge, pro- and mesotarsomeres 4 narrow and slightly emarginate at apex.

Females. Externally identical to males except antennomeres 5–11 approximately half length of those in male.

Diagnosis. Mordellistena virginica has a dorsal habitus similar to Mordellistena vera Liljeblad, 1917 , especially in the structure of the antennae. It differs from M. vera in having rufous rather than blackish elytra and rufous edging along the base of the pronotum, which is entirely dark in M. vera . Additionally, the shape (width, length, and angle) of the parameres and median lobes are distinctly different in M. vera and M. virginica ( Figs. 8A–D ).

Variation. Body length 3.2–4.2 mm to tip of elytra, 4.1–5.2 mm to tip of pygidium; pygidium sometimes dark at base, pale reddish in apical half; elytra sometimes with darker central area; amount of rufous edging along basal edge of pronotum variable; hind leg ridge count sometimes difficult to interpret due to the one or two additional short rows of dark bristles on the tibia and tarsomeres.

Etymology. Mordellistena virginica is named in honor of the Commonwealth of Virginia, the only political entity from which this species is currently known.

Biology. Mordellistena virginica is currently known from 21 specimens (10 male and 11 female) collected from the Piedmont (n = 20) and Coastal Plain physiographic province of Virginia in swamp and floodplain forest of Turkey Run and Great Falls parks within the Potomac Gorge and at Dyke Marsh Wildlife Preserve. It was collected in Malaise traps set during 1 June –4 September.

Figures

Fig. 7. Mordellistena virginica, new species, holotype, male. A) Dorsal, B) Lateral, C) Antenna. Virginia, Fairfax County, Great Falls Park, swamp, Malaise trap, 1–15 July 2009, D. Smith and B. Steury. Length 3.9 mm to tip of elytra, 4.5 mm to tip of pygidium.

Fig. 8. Parameres. Mordellistena vera: A) Dorsal, B) Lateral. Mordellistena virginica, new species: C) Dorsal, D) Lateral.