Amblopusa vancouverensis Yoo & Ahn, 2020

Yoo, In-Seong & Ahn, Kee-Jeong, 2020, Discovery of a new intertidal species, Amblopusa vancouverensis from Vancouver Island, Canada with notes on Amblopusa brevipes Casey (Coleoptera, Staphylinidae Aleocharinae), Zootaxa 4803 (3), pp. 505-514 : 511-513

Amblopusa vancouverensis Yoo & Ahn sp. nov.

( Figs. 2 , 18–25 , 29 )

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Description. BL 1.7–2.1 mm, elongate, parallel-sided, somewhat flattened dorsally. Body light brown to brown, abdomen except segment VIII darker. Male. Head round, about 1.14 times as long as wide; lateral margin somewhat linear; dorsal surface flattened, evenly pubescent; microsculpture of dorsal surface imbricate, anisodiametric. Occipital carina more or less linear, complete. Eyes very small with about 6 facets, about 0.11–0.12 times as long as temple, about 0.08 times as long as head. Labrum transverse, anterior margin slightly convex. Mandibles ( Figs. 19–20 ) asymmetrical; left and right ones with somewhat different irregular serrations. Labium ( Fig. 22 ) with ligula rod-shaped, entire at apex; ligula shorter than half length of palpomere 1, as long as palpomere 2; labial palpi with 2 articles, substyliform, palpomere 2 shorter than half length of 1; twin pores present, prementum without pseudopores medially and laterally; setal pores present. Maxilla ( Fig. 20 ) with galea shorter and narrower than lacinia; palpomere 3 dilated apically; internal surface of lacinia with large spine apically, 5 short spines more medially and 1 large spine behind these. Memtum ( Fig. 22 ) trapezoidal, about 0.7 times as long as wide; anterior margin broadly and moderately emarginate; seta v absent. Submentum with numerous punctures and setae; punctation on surface slightly denser than those of mentum. Antenna ( Fig. 18 ) short, increasing in width toward apex, not exceeding posterior margin of pronotum when extended posteriorly; antennomere 1 about 1.1 times as long as 2, 4–6 similar in length, last antennomere about 1.5 times as long as the preceding one; antennomere 4 somewhat round, 5–10 transverse. Neck absent. Pronotum subquadrate, as long as wide; lateral margin sinuate; hypomeron broad. Mesoventral process pointed at apex. Mesocoxal cavities contiguous, posterior margin of mesocoxal cavities not carinate. Elytron about 1.7–1.8 times as long as wide, about 0.8–0.9 times as long as pronotum; postero-lateral margin linear, not sinuate. Hind wings absent. Hind tarsus slightly longer than half length of hind tibia. Tarsal formula 4-4-5. One empodial seta present, much shorter than claws. Abdomen flattened dorsally and distinctly convex ventrally, widened posteriorly; abdominal tergites III–VII strongly impressed at base; abdominal sternite III with basal carina abruptly V-shaped; abdominal tergite VIII with 4 macrosetae on each side of midline, posterior margin straight; abdominal sternite VIII with 5 macrosetae on each side of midline, posterior margin prolonged medially. Median lobe ( Fig. 23 ) of aedeagus with apical lobe strongly curved. Paramere of aedeagus as in Figs. 24–25 . Female. Posterior margin of abdominal sternite VIII less prolonged than male. Spermatheca ( Fig. 29 ) with short duct and not coiled.

Type series. Holotype ♂, labeled as follows: CANADA: British Columbia, Vancouver Island, Ucluelet, Wild Pacific Trail , N48°55′39.23″ E125°32′22.74″ 6 m, 16 XI 2018, JH Song, JS Lee, 0–20 cm deep, near log on gravel beach, flotation ; Holotype, Amblopusa vancouverensis Yoo & Ahn, Desig. I. -S. Yoo & K.-J. Ahn 2019. Paratypes 20, same data as holotype (8 exx.; 1♂ 1♀ on slides; 10 exx. in 100% EtOH) .

Distribution. Canada (Vancouver Island).

Remarks. Amblopusa vancouverensis is similar to A. brevipes but can be easily distinguished by: smaller body, longer head with linear lateral margins, shorter antennomeres, and different shapes in both median lobe and spermatheca.

The specimens were collected in 0–20 cm deep, near log on gravel beach in Vancouver Island by flotation method ( Figs. 5–6 ).

Figures

FIGURES 1–2. Adult habitus. 1: Amblopusa brevipes, 2.1 mm; 2: A. vancouverensis, holotype (male, abdominal segment VIII including genitalia dissected), 1.6 mm.

FIGURES 18–25. Amblopusa vancouverensis. 18: antenna; 19: mandible, left, dorsal aspect; 20: mandible, right, dorsal aspect; 21: maxilla, left, ventral aspect; 22: labium and mentum, ventral aspect; 23: median lobe of aedeagus, lateral aspect; 24: paramere of aedeagus, lateral aspect; 25: apical lobe of paramere (scales: 0.05 mm for 19–20, 25; 0.1 mm for 18, 21–24)

FIGURES 26–29. Spermathecae. 26–28: Amblopusa brevipes (26, from Agattu Island; 27, from Vancouver Island; 28, from Fort Wrangel, Alaska); 29: A. vancouverensis.

FIGURES 5–6. Type locality of Amblopusa vancouverensis. 5: Ucluelet, Wild Pacific Trail, Vancouver Is., Canada; 6: microhabitat: 0–20 cm deep, gravel beach.