Eusphalerum caterinoi, Zanetti, 2014

Zanetti, Adriano, 2014, Taxonomic revision of North American Eusphalerum Kraatz, 1857 (Coleoptera, Staphylinidae, Omaliinae), Insecta Mundi 2014 (379), pp. 1-80 : 35-36

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Eusphalerum caterinoi

n. sp.

Eusphalerum caterinoi n. sp.

Material examined (18 specimens)

Holotype m 7 paratypes mm 6 paratypes ff California Lake Co Middletown (5 mi. NW) on Manzanita ( Arctostaphylos sp. ) 24.03.1964 leg. C.W. OBrien (CNC)

Other paratypes. USA. California 1 m Monterey Co UC Big Creek Reserve Gamboa Rd 36.0695 oN 121.5875 oW 28.03.2004 leg. Caterino (SBMNH) ; 1 f Monterey Co UC Big Creek Reserve Canogas Falls Tr. 36.0616 oN 121.5545 oW 27.03.2004 leg. Caterino (SBMNH) ; 1 f San Luis Obispo Co LPNF Cuesta Ridge 35.3661 oN 120.6618 oW 14.04.2005 leg. Caterino (SBMNH) ; 1 f Santa Cruz Co Santa Cruz (SBMNH) ;

Measurements. Head length: 0.22-0.29; head width: 0.49-0.55; pronotal length: 0.40-0.48; pronotal width: 0.59-0.70; elytral length: 0.92-0.98; elytral width: 0.74-0.88; length (clypeus to apex of elytra): 1.48-1.72; total length: 1.7-2.2.

Etymology. The species is dedicated to one of the collectors, specialist on Histeridae and Californian beetles Michael Caterino.

Description. Habitus as in Fig. 102 View Figures 93-108 . Head, pronotum and elytra brown, head somewhat darker than pronotum; abdomen dark brown; ventral surface brown; legs yellowish; antennae yellowish, darkened from antennomere 7.

Head with prominent eyes, postocular carina not much evident, temples convergent caudad in straight line, medial margin of eyes without longitudinal wrinkles. Ground of head scarcely impressed, postantennal depressions and tentorial pits superficial, confluent in 2 longitudinal depressed areas. Neck not separated from the head. Punctation sparse and irregular, ground with superficial microsculpture. Antennae rather short, antennomere 1 and 2 ovoid, 2 scarcely elongate, 3 twice as long as wide, 4-6 subquadrate, 7-10 transverse, 11 less than twice as long as wide, conical at apex.

Pronotum transverse (ratio width/length = 1.5 on average), convex, widest just in front of middle, anterior margin slightly narrower than posterior, lateral margins rounded in middle, convergent caudad in almost straight line, very feebly sinuate in front of posterior angles that are well marked and scarcely obtuse. Punctation sparse and superficial on rather irregular ground with isodiametric microsculpture, rather glossy, pubescence short but visible, depressions near posterior angles wide, extending in front of middle of lateral margins.

Elytra scarcely elongate (ratio length from scutellum to apex / combined width of elytra = 1.0), scarcely widened towards apex, truncate at apex in both sexes, punctation coarser and denser than on pronotum, confluent on glossy ground, pubescence short but visible.

Abdomen almost dull, microsculpture clearly visible, pubescence decumbent. Apex of abdomen in male curved ventrad.

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

Sternite of male genital segment modified as in Fig. 107 and 108 View Figures 93-108 , sternite VIII as in Fig. 106 and 108 View Figures 93-108 .

Aedeagus as in Fig. 103 View Figures 93-108 .

Accessory sclerites of female reduced ( Fig. 104 View Figures 93-108 ), scarcely visible, spermatheca as in Fig. 105 View Figures 93-108 .

Comparative notes. The small size, entirely dark color (except legs), presence of postocular carina (even if not much marked) and especially shape male sternite IX are distinctive. A confusion with the plate of the sternite VIII of some dark populations of E. californicum is possible because this structure covers the genital segment, which is therefore scarcely visible in ventral view. Size is anyway always smaller than in E. californicum . Eusphalerum caterinoi is most similar to E. luteipes , but that species has modified male middle tibiae, unmodified sternite 9 and pronotum without microsculpture. The aedeagi are also clearly different ( Fig. 103 View Figures 93-108 and 110)

Distribution. UNITED STATES: California coastal ranges (Map 8).

Natural history. All the specimens were collected at low altitude, Manzanita ( Arctostaphylos sp. , Ericaceae ) is reported as host plant. Chaparral is probably the habitat of the species. All specimens were collected in early spring (March-April).