Atheta struyvei Klimaszewski and Chandler, 2023

Klimaszewski, Jan, Chandler, Donald S., Davies, Anthony & Bourdon, Caroline, 2023, Aleocharine rove beetles of New Hampshire, USA: new taxa and new records (Coleoptera, Staphylinidae, Aleocharinae), Zootaxa 5364 (1), pp. 1-141 : 40-42

69. Atheta struyvei Klimaszewski and Chandler sp. n.

Figs. 5a – h , Table 1

Holotype (male). Canada , Quebec, Saint-Joseph-du-Lac, 45.53°N, 74.02°W, car netting, 11.VII.2016, T. Struyve ( CNC) . Paratypes: CANADA, Ontario, Auburn , 43.729, -81.528, 11.V.2009, A. Brunke, pitfall, hedgerow bordering soybean field (1 female, DEBU) . Quebec, Saint-Joseph-du-Lac, 45.53°N, 74.02°W, car netting, 11.VII.2016, T. Struyve ( CNC), 1 female . Oka , 45.49°N, 71.01°W, 12.VII.2016, car netting, T. Struyve ( CNC, CBG), 1 male, 1 female, 2 males . Site 23FB-A, Forêt Boucher, Gatineau , 45°25’15”N 75°49’00”O, 18–23.VI.2023, érablière à caryer, piège interception de F. Génier & C. LeBlond: FB23-07 ( FGC) 3 males, 1 female . USA, New Hampshire, Strafford Co.: College Woods, Durham , 28.IX–12.X.2006, N43.14045°, W70.94637°, pitfall, ZOOL 745/845 class, forest, 1 male .

Etymology. This species is named for our colleague Tim Struyve, Mechelen, Belgium, who collected most of the type series.

Diagnosis. This species is distinct by its small size, length of 2.0–2.4 mm, yellow-brown body color, strongly transverse apical antennomeres ( Fig. 5a ); male tergite VIII with four large teeth ( Fig. 5d ), median lobe of aedeagus with enlarged bulbus, short tubus with narrow apex, internal sac with sinuate flagellum and associated structure ( Fig. 5b,c ), and spermatheca with small globose capsule and stem long, sinuate, and looped posteriorly ( Fig. 5h ).

Description. Body narrowly subparallel, moderately convex, length 2.0–2.4 mm; colour brown to dark brown, with antennomeres I–III, palps, legs, elytra and apical part of abdomen light brown to yellowish-brown, integument moderately glossy ( Fig. 5a ); forebody with pubescence fine and sparse, denser on elytra; head narrower than pronotum, genae shorter than eyes in dorsal view; antennae moderately thick, antennomere IV moderately transverse, V–VII moderately transverse, VII–X strongly transverse each at least 2 times as wide as long; pronotum distinctly transverse, widest at middle, slightly narrower than elytra; elytra at suture slightly longer than pronotum, posterior margin gently sinuate, lateral emarginations moderate; abdomen mostly subparallel. MALE. Apical margin of tergite VIII with four apical teeth ( Fig. 5d ); sternite VIII triangularly produced apically, apex pointed ( Fig. 5e ); median lobe of aedeagus in lateral view with bulbus enlarged and long and tubus short, almost straight ventrally, with apex narrow ( Fig. 5b ); in dorsal view bulbus narrowly oval, tubus short and triangular apically ( Fig. 5c ); flagellum and affiliated internal structures elongate and sinuate in shape ( Figs. 5b,c ). FEMALE. Tergite VIII with apical margin truncate and slightly emarginate medially ( Fig. 5f ); sternite VIII rounded apically and slightly pointed medially ( Fig. 5g ); spermatheca with capsule spherical connected to short neck, stem strongly sinuate and narrowly looped posteriorly ( Fig. 5h ).

Distribution. Nearctic. Canada: ON, QC. USA: NH.

Collection and Habitat data. The type specimens were captured in July, and September/October. Most Canadian specimens were collected by car netting in forested areas, but also taken by a FIT in a maple-hickory forest; the NH specimen was found in a pitfall trap.

Comments. Atheta struyvei , is very distinct morphologically but is not similar to any described Atheta species known to us from North America. The subgeneric status is unknown, but an affiliation with the subgenus Alaobia Thomson is possible based on the similarity to European Alaobia scapularis (Sahlberg) ., Atheta struyvei , shares the following character states with the genus Alaobia : transverse and distinctly convex pronotum with posteriorly directed pubescnence, lateral margins round and slightly narrow to apex; strongly transverse antennomeres V-X; hypomera partially visible in lateral aspect; mesocoxal cavities moderately separated; mesoventral process round or slightly pointed at apex, reaching to 2/3–3/4 of mesocoxa; and ligula fusiform, divided into two lobes in apical third to half of its length. There are two Nearctic species of Alaobia , A. (A) ventricosa Bernhauer and A. (A.) trinotata (Kraatz) , both are different externally and genitally from the type species. A review of all Alaobia species is needed to clarify subgeneric status of species currently included in this subgenus.

Figures

FIGURE 5a–h. Atheta struyvei Klimaszewski and Chandler sp. n.: (a) habitus in dorsal view; (b) median lobe of aedeagus in lateral view; (c) median lobe of aedeagus in dorsal view; (d) male tergite VIII; (e) male sternite VIII; (f) female tergite VIII; (g) female sternite VIII; (h) spermatheca. Scale bar for habitus = 1mm; remaining scale bars = 0.2mm.