Agnathus secundus, Jelínek & Kubáň, 2009

Jelínek, Josef & Kubáň, Vítězslav, 2009, A review of the genus Agnathus (Coleoptera: Pyrochroidae: Agnathinae), with description of Agnathus secundus sp. nov. from China, Acta Entomologica Musei Nationalis Pragae 49 (1), pp. 253-281 : 258-262

Agnathus secundus sp. nov.

( Figs. 1–4 , 10-12 )

Type locality. Southwestern China, northeastern Yunnan province, Habashan Mts., western of Haba village, 27°22′54.3″N, 100°06′03.2″ E, 3200 m a.s.l.

Type material. HOLOTYPE: J, ‘ CHINA, N.W. Yunnan, Haba shan – Haba , 3200 m, N 27°22′54.3″, E 100°06′03.2″, 15.7.2006, leg. Janata M. ’ ( NMPC) . PARATYPES: 3 ♀♀, ‘CHINA-SW, NW Yunnan, Hengduan Mts.: massif BAIMA env., ~ 3900 m, 28°20′N 99°03′E, 27.vii.1996, V. Kubáň leg.’ ( IJCO, JRCP, NMPC).

Description. Body oblong, pronotum strongly transversely convex and constricted at basal fourth, dull, elytra moderately transversely convex (flattened along suture), shining. Body black, basal fourth of elytra dark red with the colour extending more caudad along suture; mouthparts, antennae and legs dark brown. Vestiture dark, thin, long and recumbent. Dense short white tomentum making up well-defined pattern on elytra consisting of short and thin transverse bar at posterior end of humeral bulge, narrow zigzag transverse band at about one third of elytra and reaching from lateral margin to suture, broad transverse bar at ca. two thirds of elytral length, broadly interrupted at suture, and small apical area projecting anteriorly along suture ( Fig. 1 ). Body length 5.2 mm, width 1.7 mm.

Head transverse, width across eyes ca. twice the length between posterior ends of eyes to anterior margin of clypeus. Eyes strongly convex, prominent, coarsely facetted. Temples strongly converging posteriorly, nearly as long as antennomere IV. Frons flat, shallowly longitudinally impressed besides antennal insertions, its anterior margin truncate with broad, impunctate and shining border. Punctures smaller than eye facets and separated by less than one diameter, becoming sparser anteriorly; interspaces obsoletely alutaceous, dull. Antennae ca. as long as pronotum, eleven-segmented with three-segmented subcylindrical club. Antennomeres I to XI 1.12, 1.07, 1.83, 1.66, 1.66, 1.33, 1.33, 1.33, 1.00, 0.72 and 1.09 times as long as wide, respectively. Width of scape 1.23 times that of pedicel, width of antennal club 1.83 times that of flagellum, terminal antennomere subovate, asymmetrically pointed ( Fig. 2 ).

Ventral side of head broadly arcuately impressed. Collum at sides densely punctate and transversely rugose. Gular lines narrowly interrupted in the middle, with broad impunctate stripe along their outer side. Gula in anterior half diffusely punctate, in posterior half impunctate with shallow transverse wrinkles.

Pronotum 1.55 times as long as wide, widest at anterior margin, strongly constricted at basal fourth, gradually narrowed towards the constriction. Constriction developed as deeply incised furrow separating differently punctate anterior and posterior portion of prothorax. Base in the middle with transverse groove curved laterocraniad at sides and partly overlapped by its raised anterior edge ( Fig. 4 ). Punctures deep, in front of constriction and at sides almost equal in size to eye facets and separated by ca. one diameter, becoming gradually smaller and less regularly dispersed anteriorly; interspaces densely reticulate, dull. Basal border and lateral parts behind prebasal constriction sparsely punctate with smaller and shallower punctures, interspaces shallowly reticulate, somewhat shining. Scutellum small, heart-shaped, densely finely punctulate. Prosternum short, densely punctate with intermixed larger punctures. Mesosternum long, triangular, shining, densely finely punctate with deep pit-shaped punctures fairly equal in size to eye-facets and separated by ca. one diameter or less. Mesepisterna large, triangular, punctate like prosternum, but the pit-shaped punctures larger and closer than those on mesosternum, widely separated from mesocoxal cavities by broad posterolateral processes of mesosternum. Narrow praepectus developed on mesepisterna, in middle interrupted by pointed anterior tip of mesosternum. Posterior intercoxal process of mesosternum narrow, pointed, with blunt median longitudinal carina. Metasternum convex, shining, with fine simple and dense punctures intermixed at sides and behind mesocoxae with widely spaced pit-shaped punctures equal in size to eye facets. Mesocoxal lines close to posterior margins of coxal cavities, interconnected at obtuse angle in middle. Posterior intercoxal margin with angulate excision prolonged by short and very deep mediolongitudinal groove. Metepisterna with pit-shaped punctures closer than those on metasternum, fine punctures indistinct.

Elytra twice as long as their combined width, ovate, widest somewhat behind midlength and reaching maximum length at suture. Surface strongly transversely convex at sides, less so at suture; lateral margins not visible simultaneously from above except for short portion behind humeral bulge. Humeral bulges strongly prominent, concealing humeral angles. Broader and lower bulge situated posteromesad of humeral bulge on each elytron. Elytra moderately transversely depressed behind the bulges, the depression extending laterally towards lateral margins of elytra. Surface impressed along suture between posterior transverse bar and apical white spot. Punctures ca. as large as eye facets, umbilicate, irregularly diffuse, separated by one to several diameters; interspaces microscopically punctulate, shining; large punctures abruptly replaced with fine, indistinct and widely spaced punctures behind posterior white bar.

Femora long and slender, rugosely punctate at distal end, ratios of length-to-width of pro-, meso- and metafemur equal to 4.1, 5.0 and 5.8 respectively. Tibiae slender, without longitudinal keels or angles (cross-section oval), widest at distal end, ratios of length-to-width of pro-, meso- and metatibia equal to 6.5, 6.5 and 8.5, respectively. Pro- and metatibiae straight, mesotibia broadly and shallowly concave behind midlength. Tarsal formula 5–5–4, all tarsi simple, slender, tarsal claws obtusely angulate at their base.

Protarsus 0.73 times as long as fore tibia. Tarsomere I twice as long as wide, tarsomeres II and III shorter, subequal. Terminal tarsomere as long as 0.38 of total length of tarsus, slightly longer than tarsomeres I and II combined. Mesotarsus almost as long as mesotibia, ratio of lengths of tarsomeres I–V as 23:10:10:6:20. Length of metatarsus 0.8 times that of metatibia, ratios of lengths of tarsomeres I–IV as 30:12:8:20.

Abdominal ventrites duller than metaventrite, densely microscopically punctulate with widely scattered larger punctures, the latter smaller than eye facets. Ratios of lengths of ventrites I–V as 75:45:25:20:15. First ventrite with triangular anterior intercoxal process and posterior margin broadly arcuately outcurved in its median third. Posterior margins of following ventrites straight.

Male genitalia. Tegmen gradually tapering towards narrowly rounded apex, its lateral margins almost rectilinear. Tip of median lobe blunt ( Fig. 3 ).

Variation. No substantial variation or sexual dimorphism is apparent in the type series. Body length 5.2–6.0 mm, width 1.7–2.0 mm. Pronotum 1.52–1.56 times as long as wide, elytra 1.95–2.01 times as long as their combined width.

Differential diagnosis. Agnathus secundus sp. nov. differs from A. decoratus in the traits summarized in Table 1.

Etymology. Secundus, Latin adjective meaning second, for the species is the second known species of the genus.

Collecting circumstances. The holotype (male) was collected by M. Janata (pers. comm.) running along with some Cleridae on fallen trunks of various conifers ( Abies sp. , Pinus sp. , Picea sp. and Larix sp. ) ( Figs. 11–12 ). Three paratypes (females) were collected by one of us (V.K.) in the massif Baima in a deep valley directed southwards on lower parts of southeastern slopes at an altitude of 3,900 m. The adults were quickly running around in bark crevices of a fallen trunk of a fir ( Abies sp. ) during sunny warm weather at about midday. The behaviour of the beetles resembled that of some species of the family Cleridae and was suggestive of prey-searching behaviour of a predator. Trunk of a freshly cut tree, about 4 m long and about 40 cm in diameter laid on a place insolated between ca. 10 a.m. and 3 p. m (see Fig. 10 ). A fast torrent was found about 150 m from the spot, with pieces of dead wood located in more quiet water.

Two weeks later, V.K. observed one specimen, which he failed to collect, on a similar locality in Hengduan Mts., massif Meili, 28°00′N 98°52′E, 11.vii.1996, about 40 km southwest of the first locality (Baima massif). The beetle was running at about midday on the bark of an uprooted but still fresh fir tree, 15–20 m high and ca. 80 cm in diameter, hanging on its branches 1–4 m above surface. The tree was situated in a lower part of a cirque with a spring at an altitude of 3,650 m on a southern slope with remnants of a predominantly coniferous forest near tree-line. There was also a small brook about 200 m away from the tree.

Distribution. Mountain primeval forests of Yunnan Province in southwestern China.

Figures

Figs. 1–7. 1–4 – Agnathus secundus sp. nov.: 1 – holotype, habitus, 5.2 mm; 2 – antenna; 3 – aedeagus; 4 – pronotum. 5–7 – A. decoratus (Germar, 1818): 5 – habitus, specimen from Czech Republic (Moravia, Strážnice env.), 4.8 mm; 6 – antenna; 7 – aedeagus.

Figs. 9–10. 9 – Czech Republic, Moravia, Litovelské Pomoraví Protected Landscape Area – locality with common occurrence of Agnathus decoratus (Germar, 1818). Photo by E. Svobodová.10 – China, northeastern Yunnan province, Hengduan Mts., Baima Massif, ~3900 m a.s.l. – locality of paratypes of A. secundus sp. nov. Photo by V. Kubáň.

Figs.11–12. China, northeastern Yunnan province, Habashan Mts., west of Haba village, 3200 m a.s.l. – type locality of Agnathus secundus sp. nov. Photos by M. Janata.