Eusphalerum newtoni Zanetti, 2014

Zanetti, Adriano, 2014, Taxonomic revision of North American Eusphalerum Kraatz, 1857 (Coleoptera, Staphylinidae, Omaliinae), Insecta Mundi 2014 (379), pp. 1-80 : 55-56

Eusphalerum newtoni Zanetti n. sp.

Material examined (77 specimens)

Holotype m 3 paratypes mm 1 paratype f California Marin Co Inverness , (3.1 mi. NW of) 200 ft Alnus forest, on flowers Heracleum lanatum 22.05.1976 leg. A. Newton and M. Thayer (FMNH)

Other paratypes. CANADA. British Columbia 4 mm 2 ff Bowser 5/ 19.06.1955 leg. W.J. Brown & R. Coyles (CNC) ; 1 m Mission City 3.06.1953 leg. W. Mason (CNC) ; 1 m Prince Rupert, Mt. Hays 1 2000 29.06.1968 leg. Campbell & Smetana (CNC) ; 2 mm 1 f Vancouver Is., Port Renfrew 12.07.1984 leg. L. Huggert (MZLU) . USA. Oregon 2 mm 1 f Douglas Co Reedsport (5 km S) 7.06.1984 leg. R. Danielsson (MZLU) ; Washington 1 f Clallam Co Fairholm (6 mi. ESE), Olympic Nat. Forest sweeping on forest roads and meadows 11.08.1988 leg. R. Baranowski (MZLU) ; 4 mm 5 ff Clallam Co Olympic NP, Lake Creek at Hurricane Ridge Rd. 625 m mixed conifer forest on flowers Tiarella trifoliata 09.07.1988 leg. A. Newton M. Thayer (FMNH) ; 11 mm 9 ff Clallam Co Olympic NP, Lake Creek at Hurricane Ridge Rd. 625 m mixed conifer forest on flowers Clintonia uniflora 09.07.1988 leg. A. Newton M. Thayer (FMNH) ; 2 ff Clallam Co Olympic NP, Lake Creek at Hurricane Ridge Rd. 625 m mixed conifer forest on flowers Cornus canadensis 09.07.1988 leg. A. Newton M. Thayer (FMNH) ; 1 m 3 f Clallam Co Olympic NP, Lake Creek at Hurricane Ridge Rd. 625 m mixed conifer forest on flowers Asteraceae 09.07.1988 leg. A. Newton M. Thayer (FMNH) ; 1 m Swob ?? 24.05.19?? leg. L. Russell (FMNH) ; California 3 mm 1 f Colusa Co Goat Mt. (?) 30.05.1959 (CNC) ; 1 m Marin Co Taylor State Pk. flowers Rubus parviflorus 8.05.1949 leg. H.P. Leech (CNC) ; 6 mm 9 ff Marin Co Alpine Lk 11.06.1964 leg. Doyen (FMNH) ; 1 m Mendocino 26.05.1955 leg. Helfer (CNC) ; 1 f Napa Co Calistoga (11.4 mi. N) 1600 21.05.1976 leg. A. Newton and M. Thayer (FMNH) .

Etymology. The species is dedicated to one of its collectors, the student of evolution of Staphylinidae Alfred F. Newton.

Measurements. Head length: 0.27-0.33; head width: 0.53-0.59; pronotal length: 0.40-0.53; pronotal width: 0.64-0.75; elytral length: 0.99-1.35; elytral width: 0.88-1.11; length (clypeus to apex of elytra): 1.59-2.03; total length: 1.7-2.9.

Description. Habitus as in Fig. 141. Head from yellowish slightly darkened on vertex to brown with anterior part medially yellowish; pronotum yellowish, sometimes darkened on discal part; elytra yellowish; abdomen brown with paler apex in male, entirely yellowish in female; prosternum yellowish; metasternum brownish yellow (male) or yellowish (female); legs yellowish; antennae yellowish at base, more or less darkened from antennomere 6.

Head with prominent eyes, postocular carina well marked, temples short and convergent caudad, medial margin of eyes with microsculpture forming longitudinal wrinkles, postantennal depressions confluent caudally with the deep tentorial pits forming 2 longitudinal depressions in front of ocelli. Neck wide, not separated from the head. Punctation rather sparse and superficial on microsculptured ground. Antennae moderately elongate, antennomere 1 about twice as long as wide, 2 ovoid, 3 thin, elongate, twice as long as wide, 4-5 longer than wide, 6 subquadrate, 7-10 slightly transverse, 11 twice as long as wide, cylindrical at base and conical at apex.

Pronotum transverse (ratio width/length = 1.4 on average), convex, with a median longitudinal impression in large males, a narrower furrow in the small males and in females. Pronotum widest in anterior half, anterior margin slightly narrower than posterior, lateral margins rounded in anterior third, usually convergent caudad in straight line in posterior two thirds, posterior angles marked and scarcely obtuse, punctation rather sparse and superficial, ground with isodiametric microsculpture, pubescence extremely short, scarcely visible, depressions near posterior angles wide, extending in front of middle of lateral margin.

Elytra scarcely elongate (ratio length from scutellum to apex/combined width of elytra = 1.1), truncate at apex in both sexes, scarcely widened towards apex, punctation stronger than on pronotum, dense, rather confluent, ground glossy, pubescence extremely short, scarcely visible.

Abdomen rather glossy, microsculpture superficial, with decumbent pubescence.

Tibiae straight in both sexes, middle tibiae of male slightly curved internally at apex, tarsomere 5 of posterior tarsi slightly shorter than 1-4 together.

Aedeagus of the type (California) as in Fig. 142, with a large copulatory sclerite, divided in 2 branches in the basal portion and curved in lateral view. In the Northern populations, from British Columbia to Oregon, the copulatory sclerite is somewhat longer.

Accessory sclerites of female as in Fig. 143, spermatheca as in Fig. 144.

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

Distribution. CANADA: British Columbia; UNITED STATES: Oregon, California (Map 7).

Natural history. The species was documented at low altitude, up to 625 m a.s.l.. Some records are from mixed coniferous forest, one from Alnus forest. Known host plants: Tiarella trifoliata L. ( Saxifragaceae ), Clintonia uniflora (Menz. ex Sch. & Sch.) Kunth (Liliaceae) , Cornus canadensis L. ( Cornaceae ), Heracleum maximum Bartram (= H. lanatum ) ( Apiaceae ), Rubus parviflorus Nutt. (Rosaceae) , and unidentified Asteraceae . Captures from May (California) to August (Washington).