Nalassus (Helopocerodes) olgae, Nabozhenko, M. V. & Ivanov, S. N., 2015

Nabozhenko, M. V. & Ivanov, S. N., 2015, A new Nalassus Mulsant, 1854 (Coleoptera: Tenebrionidae: Helopini), the first representative of the genus from the Russian Far East, Zootaxa 3955 (1), pp. 137-141 : 138-139

Nalassus (Helopocerodes) olgae sp. n.

( Figs 1–12 )

Type material. Holotype, ♂ and 42 paratypes (21♂, 21♀) with label: Russia, Primorsky kray, Oktyabrsky District, near Chernyatino, Sinelovka Mt., 17.05.– 28.06.2014 (leg. S.N. Ivanov). Holotype and 3 paratypes are deposited in Zoological Institute RAS (St. Petersburg), 4 paratypes are deposited in Institute of Biology and Soil Science, Far Eastern Branch of RAS (Vladivostok, Russia), 4 paratypes (in ethanol) are in Zoological Department of Ege University (Bornova, Izmir, Turkey) other paratypes are in private collections of M.V. Nabozhenko and S.N. Ivanov.

Description. Male. Body dorsally and ventrally black, weakly convex, moderately shining. Legs, antennae and mouthparts brown. Head widest at eye level. Eyes large, moderately convex. Ratio of head width at level of eyes to distance between eyes 1.65. Anterior margin of clypeus straight. Genae strongly rounded. Outer margin of head between genae and clypeus with small sinuation. Punctation of head coarse and dense: diameter of punctures subequal to distance between them on frons and visibly more than distance between punctures around frons and on clypeus. Antennae moderately long (reaching 1/6 of elytral length), with 3 apical antennomeres extending beyond base of pronotum. Antennomeres 4–8 visibly thickened. Ratio of length to width of antennomeres 2–11 (antennomere 9—ratio of width to length): 1.27, 2.25, 1.6, 1.4, 1.4, 1.35, 1.3, 1.06, 1.06 (wider than long), 1.06. Antennomere 3 2× as long as antennomere 2 and 1.2× as long as antennomere 4. Antennomeres 9–11 shorter than antennomeres 3–7.

Pronotum transverse (1.32× as wide as long), widest in middle, rarely before middle, 1.6× as wide as head. Lateral sides of pronotum moderately regularly rounded, rarely slightly sinuate near base. Anterior margin weakly rounded, bisinuate, base straight or weakly rounded. Anterior angles not projected, obtuse, widely rounded; posterior angles obtuse, narrowly rounded on apex. All margins of pronotum beaded, lateral margins wider beaded in basal 1/4. Disc regularly convex with widely flattened lateral sides. Punctation of disc moderately coarse and dense: diameter of punctures subequal to distance between them, punctures round. Medial line usually without visible punctation. Hypomera with flattened outer margins, longitudinal wrinkles and sparse recumbent setae. Prosternal process weakly convex.

Elytra elongate (1.6× as long as wide), 2.5× as long and 1.2× as wide as pronotum, 1.9–2× as wide as head. Lateral elytral sides weakly rounded. Elytra moderately convex, dorsal part of epipleural carina invisible dorsally. Punctures in striae merged in deep furrows. Elytral intervals weakly convex, with moderately coarse and dense punctation (distance between punctures 2–3× as long as puncture diameter), 8th interval more convex on apex and connected with elytral margin. Epipleura and epipleural carina not reaching elytral apex.

Wings very short (1/4 of elytral length), reduced. Venation also subreduced, only 3 veins are presented: radial (R), main cubital (Сu) and short anal (A) ( Fig. 7 ).

Metaventrite ( Fig. 5 ) with coarse, moderately dense punctation, convex in anterior half and with smooth tubercle, with T-shaped deep depression near base. Abdominal ventrites bare, with dense, moderately coarse punctation, ventrites 1–2 with wrinkles on lateral sides; ventrite 5 with very weak wide depression.

Each trochanter with 1 long seta. Tibia straight, tarsi not widened.

Genitalia and terminalia ( Figs 8–11 ). Aedeagus short (about 2 mm), weakly sclerotized. Apical piece (without ventral processes) 1.6× as short as basal piece, median lobe baculi not merged, narrow, with acute apices ( Figs. 8, 9 ). Inner sternite VIII with deep emargination ( Fig. 11 ). Gastral spicula with pseudo trunk ( Fig. 10 ).

Body length 8–11 mm, body width 2.9–4.3 mm

Female. Antennae shorter, regularly widened to apex, antennomeres not thickened. Metaventrite ( Fig. 6 ) with weak convexity, divided by arched-shaped transverse wrinkle. Genital tubes ( Fig. 12 ): spermatheca and gland short, subequal, spermathecal basal duct absent, spermatheca without processes.

Body length 8.7–12 mm, width 3.1–5.2 mm.

Etymology. The species is named in honour of Olga Ivanova, wife of the second author.

Differential diagnosis. Nalassus olgae sp. n. is closely related to N. magyari , from which it differs by its larger body (length of N. magyari 6–7 mm), widely flattened lateral sides of pronotum and sculpture of metaventrite. The new species differs from Nalassus pekinensis by sculpture of metaventrite, black, moderately shining body ( N. pekinensis has brown dull body), thickened antennomeres of male.

Habitat. The species was found on branches of Quercus wutaishanica , which was relatively recently recorded for Russian Far East ( Beljaev 2004). The species is rarely collected on other trees (for example apricot Prunus sp.) and shrubs ( Lespedeza ) near the oak forest.

Figures

FIGURE 1 – 4. Nalassus (Helopocerodes) olgae sp. n. 1) Male. 2) Female. 3) Map of distribution. 4) Habitat, forest of Quercus wutaishanica.

FIGURE 5 – 12. Nalassus (Helopocerodes) olgae sp. n., structure. 5) Metaventrite, male. 6) Metaventrite, female. 7) Right wing. 8) Aedeagus, ventral view. 9) Aedeagus, lateral view. 10) Gastral spicula. 11) Inner sternite VIII. 12) Female genital tubes (s—spermatheca, ov—oviduct, g—gland, vg—vagina). Scale 1 mm.