Eusphalerum parvispiculum Zanetti, 2014

Zanetti, Adriano, 2014, Taxonomic revision of North American Eusphalerum Kraatz, 1857 (Coleoptera, Staphylinidae, Omaliinae), Insecta Mundi 2014 (379), pp. 1-80 : 56-57

Eusphalerum parvispiculum Zanetti n. sp.

Material examined (102 specimens)

Holotype m 9 paratypes mm 10 paratypes ff California Calaveras Co West Point (1.1 mi. E), Winton Rd. 2800 ft. on flowers Ceanothus 20.05.1976 leg. A. Newton M. Thayer (FMNH).

Other paratypes. USA. California 2 mm 2 ff Colusa Co Goat Mt. 30.05.1959 (CNC); 1 m El Dorado Co Kyburz (8 mi. E) 5500 11.07.1966 leg. W. Gagnel (FMNH); 1 m El Dorado Co Pollock Pines 28.05.1970 leg. Chandler (FMNH); 2 mm 1 f Mather 15.06.1969 leg. K. Stephan (FMNH); 1 m 1 f Nevada Co Spenceville Wildlife Mgmnt.Area on Brodiaea 28.03.1983 leg. P.J Johnson (FMNH); 7 mm 7 ff Nevada Co Spenceville Wildlife Mgmt & Rec. Area on flowers Brodiaea 28.03.1983 leg. P.J. Johnson (FMNH); 2 ff Plumas Co Butt Valley Dam 4000 on flowers 30.06.1975 leg. A. Newton M. Thayer (FMNH); 1 f 2 mm Riverside Co James Reserve SBNF,UC 33.8081 oN 116.7734 oW 19/ 26.05.2005 leg. Caterino (SBMNH); 3 mm 1 f Riverside Co James Reserve SBNF,UC 33.8107 oN 116.7712 oN 30.05.2005 leg. Caterino (SBMNH); 5 mm 2 ff Riverside Co San Bernardino NF Fuller’s Ridge trailhead 33.8391 oN 116.7363 oW 16.07.2006 leg. Caterino & Chatzimanolis (SBMNH); 4 mm 1 f San Bernardino Co San Bernardino NF Bluff Lake 34.2187 o N 116.9663 oW 14.07.2006 leg. Caterino & Chatzimanolis (SBMNH); 1 m San Bernardino Co San Bernardino NF F.S.2 N10 34.2262 oN 116.93.68 oW 14.07.2006 leg. Caterino & Chatzimanolis (SBMNH); 1 m Riverside Co San Bernardino NF Lake Fulmor 33.8060 oN 116.7785W 15.07.2006 leg. Caterino & Chatzimanolis (SBMNH); 5 mm 3 ff Tulare Co Sequoia NF Upr., Freeman Ck. 36.138 oN 118.534 oW beaten from Ceanothus 23.06.2003 leg. Caterino (SBMNH); 1 m Tulare Co Sequoia NF, Boulder Ck. 36.1585 oN 118.5406 oW 21.07.2005 leg. Caterino (SBMNH); 1 f 2 mm Tulare Co Sequoia NF, Freeman Ck. Grove 36.146 oN 118.493 o W 21/ 22.06.2003 leg. Caterino (SBMNH); 2 mm 1 f Tulare Co Whitaker Forest UC 36.6988 oN 118.9290 oW /36.7046 oN 118.9329 oW 5/ 12.06.2006 leg. Caterino & Chatzimanolis (SBMNH); 6 mm 4 ff Pioneer (28 mi. NE) 8.07.1966 leg. C.W. OBrien (CNC); 3 mm 3 ff Nevada Co Spenceville Wildlife Mgmt & Rec. Area on flowers Brodiaea 28.03.1983 leg. Johnson (FMNH). Oregon 1 m Jackson Co Ashland (15 km E) Pinehurst 11/ 12.06.1984 leg. R. Danielsson (MZLU); 1 m 1 f Klamath Co Beatty (10 km SW) 13.06.1984 leg. R. Danielsson (MZLU);

Measurements. Head length: 0.25-0.31; head width: 0.46-0.61; pronotal length: 0.40-0.53; pronotal width: 0.64-0.75; elytral length: 0.99-1.11; elytral width: 0.90-0.99; length (clypeus to apex of elytra): 1.57-2.03; total length: 1.8-3.

Etymology. Adjective, from the latin parvus (small) and spiculum (spike), referring to the small copulatory sclerite.

Description. Habitus as in Fig. 145. Head yellowish, often somewhat darkened in posterior half; pronotum and elytra yellowish; abdomen light brown in male, yellowish with somewhat darkened apical segments in female; prosternum yellowish; metasternum yellowish or brownish yellow; legs yellowish; antennae yellowish, darkened from antennomere 6.

Head with prominent eyes, postocular carina well marked; temples short, convergent caudad; medial margin of eyes with microsculpture tending to form longitudinal wrinkles; postantennal depressions superficial, confluent caudally with marked tentorial pits, rather far in front of ocelli; neck broad, separated from head only posterior to postocular carina, not medially. Punctation rather sparse, mostly on vertex, ground microsculptured. Antennae rather robust, segments antennomeres 1-2 ovoid, 3 twice as long as wide, 4-5 subquadrate, 6-10 wider than long, 10 about twice as wide as long, 11 twice as long as wide, cylindrical at base, conical at apex.

Pronotum transverse (ratio width-length = 1.4-1.6), usually convex in males, with a wide slight median impression in male, in female reduced to one or 2 median impressions near anterior and/or posterior margins. Anterior margin slightly wider than posterior. Pronotum widest in front of middle, with rounded lateral margins, convergent caudad in almost straight line, somewhat sinuate in front of posterior margins, which are marked and scarcely obtuse. Punctation rather sparse and superficial, ground with isodiametric microculpture, pubescence extremely short, scarcely visible, depressions near posterior angles rather narrow.

Elytra scarcely elongate (ratio of length from scutellum to apex/combined width of elytra = 1), somewhat rounded at apex, punctation stronger than on pronotum, dense, somewhat confluent, ground glossy, pubescence extremely short, scarcely visible.

Abdomen rather glossy, microsculpture superficial with decumbent pubescence.

Middle tibiae of the male very feebly curved at apex. Tarsomere 5 of posterior tarsi slightly shorter than 1-4 together.

Aedeagus as in Fig. 146, internal sac with small copulatory sclerite divided into 2 slightly differentiated parts.

Accessory sclerites of female as in Fig. 147, spermatheca as in Fig. 148.

Comparative notes. Eusphalerum parvispiculum is similar to E. pothos , from which the less defined median groove on pronotum, which is more convex in males, is somewhat distinctive. Eusphalerum newtoni is even more similar, and only the shape of the aedeagus, and especially the characteristic copulatory sclerite, allows sure identification.

Distribution. UNITED STATES: California, Oregon (Map 7).

Natural history. Eusphalerum parvispiculum is probably a mountain species (documented captures between 500 and 1700 m). Brodiaea sp. (Asparagaceae) and Ceanothus sp. (( Rhamnaceae ) are reported as host species. Adults collected mostly from May through July, sometimes also in spring, from late March.