Eusphalerum pilosum Zanetti, 2014

Zanetti, Adriano, 2014, Taxonomic revision of North American Eusphalerum Kraatz, 1857 (Coleoptera, Staphylinidae, Omaliinae), Insecta Mundi 2014 (379), pp. 1-80 : 9-10

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Eusphalerum pilosum Zanetti

n. sp.

Eusphalerum pilosum Zanetti , n. sp.

Material examined. (36 specimens)

Holotype m 1 paratype m 3 paratypes ff Marin Co Lagunitas 29.03.1908 (CNC)

Other paratypes. USA. California 1 f Alameda Co Oakland Hills Salix 13.03.1962 leg. O’Brien (CNC); 7 mm Alameda Co 00.03.?? (CNC); 1 f Lake Co St. Helena Creek 02/03.1951 leg. Helfer (CNC); 2 ff Marin Co Lagunitas 7.04.1907 leg. Van Dyke (FMNH); 1 m Marin Co Point Reyes 22.03.1925 leg. Helfer (CNC); 1 f Marin Co (CNC); 1 m Mendocino Co Mendocino 20.10.1954 leg. Helfer (CNC); 8 mm 4 ff Corte Madera Cr 13.03.1910 (MSNG); 1 m 1 f Oakland, hills back of 22.03/ 12.04.1908 (CNC); 2 ff Marin Co Inverness, (3.1 mi. NW) 200 ft Alnus forest, on flowers Heracleum lanatum 22.05.1976 leg. A. Newton and M. Thayer (FMNH); 1 f Oakland, hills back of 22.03.1908 (CNC).

Measurements. Head length: 0.40-0.48; head width: 0.68-0.79; pronotal length: 0.57-0.66; pronotal width: 0.79-0.90; elytral length: 1.18-1.38; elytral width: 1.05-1.18; length (clypeus to apex of elytra): 1.94-2.40; total length: 2.2-2.8.

Etymology. Adjective, from the Latin pilosus (hairy).

Description. Habitus as in Fig. 9 and 10 View Figures 1-13 . Head, pronotum, and elytra yellowish, elytra somewhat paler, neck often darkened; abdomen from brown to dark brown in male, yellowish, somewhat darkened at apex in female; prosternum and metasternum brown; legs, antennae, and mouthparts yellowish, antennae sometimes very feebly darkened at apex.

Head very wide in the male, almost as wide as pronotum, narrower in the female, 0.7 times as wide as pronotum, with moderately prominent eyes, postocular carina absent, temples long and angulate, strongly convergent in posterior part, medial margin of eyes with some longitudinal wrinkles. Head of male rather flat, postantennal depressions superficial and tentorial pits almost absent, somewhat more impressed in female. Neck slightly separated from head. Punctation dense on glossy ground, almost without microsculpture. Antennae scarcely elongate, antennomere 1 elongate, twice as long as wide, 2 ovoid, 3 thin, twice as long as wide, 4-5 longer than wide, 6 subquadrate, 7-10 progressively widened, 10 twice as wide as long, 11 twice as long as wide, rather ovoid.

Pronotum transverse (ratio width/length = 1.4 on average), slightly impressed medially in front of posterior margin, convex, widest at the middle, anterior margin as wide as posterior in male, narrower in female, lateral margins rounded in the anterior half, somewhat sinuate in posterior half, convergent caudad in almost straight line, posterior angles marked and scarcely obtuse. Punctation dense and rather coarse, ground with isodiametric microsculpture, pubescence very long, yellowish, depressions near posterior angles wide, extending in front of middle of lateral margins, which are somewhat folded towards back and feebly crenulate.

Elytra scarcely elongate (ratio length from scutellum to apex / combined width of elytra = 1.0), widened towards apex, somewhat oblique medially in both sexes, punctation coarser and somewhat less dense than on pronotum, confluent on glossy ground, pubescence very long, yellowish and somewhat decumbent.

Abdomen dull, microsculpture clearly visible, formed by almost isodiametrical meshes, pubescence long, decumbent.

Tibiae straight in both sexes, not modified, tarsomere 5 of posterior tarsi shorter than 1-4 together.

Aedeagus as in Fig. 11 View Figures 1-13 .

Accessory sclerites of female as in Fig 12 View Figures 1-13 , spermatheca as in Fig. 13 View Figures 1-13 .

Comparative notes. See comparative notes for E. subangulatum above.

Distribution. UNITED STATES: California: Coast Range (Map 4).

Natural history. Only one altitudinal record is available (about 60 m). The only reported host plant is Heracleum maximum Bartram (= lanatum ) ( Apiaceae ), and the only habitat is Alnus forest. The species is mostly found in spring, from the beginning of March to the end of May. One record of the end of October is to be confirmed.