Neopallodes nigrescens Chen & Huang

Chen, XiaoXiao & Huang, Min, 2019, One new species and three newly recorded species of Neopallodes Reitter from China (Coleoptera, Nitidulidae, Nitidulinae), ZooKeys 880, pp. 75-84 : 75

Neopallodes nigrescens Chen & Huang sp. nov. Figs 1-17

Type material.

Holotype, ♂: China: Yunnan Province, Chuxiong City, Zixi Mountain, 2450 m a.s.l., 13-VII-2018, Xiaoxiao CHEN (NWAFU). Paratypes, 5♂♂: Yunnan Province, Dali City, Cangshan Mountain, 2610 m a.s.l., 25°39'51"N, 100°07'10"W, 05-VI-2018, Xiaoxiao CHEN (NWAFU); 1♂: Yunnan Province, Qujing City, Junzi Mountain, 2310 m a.s.l., 30-VII-2018, Xiaoxiao CHEN (NWAFU); 2♂♂: Yunnan Province, Qujing City, Yehuagou, 1980 m a.s.l., 05-VII-2018, Xiaoxiao CHEN (NWAFU); 3♂♂, 8♀♀: Same as holotype; 2♂♂: Guizhou Province, Bijie City, Shangdi Mountain, 2240 m a.s.l., 26°52'13"N, 104°18'02"W, 06-VII-2018, Xiaoxiao CHEN (NWAFU).

Description.

Body size (♂): length 2.7-3.7, width 2.1-3.1 mm.

Body: Body shiny, dorsum glabrous, abdomen with sparse and inconspicuous hairs, moderately convex dorsally and ventrally. Dorsal and ventral surface blackish with antennae and tarsi lighter, or dorsal surface blackish with elytra brightly brownish orange, ventral surface yellowish brown with metaventrite darker ( Figs 1-4 ).

Dorsal habitus: Head somewhat depressed with medium-sized eyes, punctures larger than eye-facets. Lobes of labrum clearly exposed with short excision ( Fig. 5 ). Mandible exposed from under lobes of labrum, with four small teeth on apical edge ( Fig. 15 ). Length of antenna subequal with head width, scape subcylindrical, slightly curved and about 1.5 times as long as wide, pedicel approximately subcylindrical and nearly 1.5 times as long as wide, antennomere 3 narrowed basally, antennomeres 3 and 4 longer than wide, antennomere 4 longer than antennomere 5, each of antennomeres 5-8 wider than long, antennal club compact and asymmetrical, with length nearly 0.6 times of total antennal length, antennomere 11 shorter than antennomeres 9-10 together ( Fig. 8 ). Pronotum widest at base and arcuately narrowed to apex; anterior edge deeply emarginate; posterior edge vaulted with clear projection covering base of scutellum, anterior and posterior angles blunt; surface with punctures round, slightly smaller than eye-facets and separated by 2.7-5.7 puncture diameters; interspaces smooth to alutaceous. Scutellum subtriangular with round apex, with punctures scattered and separated by 0.7-1.9 puncture diameters. Elytra about 0.9 times as long as wide together, widest at basal 1/3; surface with regular longitudinal rows of large punctures separated by 0.8-1.3 diameters in rows; rows separated from each other by 5.3-6.9 puncture diameters; interspaces microreticular, between rows of large punctures with irregular row of very fine and sparse punctures. Pygidium markedly wider than long, subtruncate at apex and with dense punctures subequal to those on pronotum ( Fig. 6 ). Anal sclerite slightly wider than long ( Fig. 7 ).

Ventral habitus: Terminal maxillary palpomere elongate and subconical ( Fig. 16 ). Terminal labial palpomere narrowing apically. Mentum pentagonal with sparse, large punctures along posterior edge ( Fig. 13 ). Antennal grooves strongly convergent behind mentum. Prosternum convex medially, with moderately subflattened process, slightly widened at subtruncate apex, and about 1.7 times as wide as scape. Mesoventrite moderately carinate. Metaventrite with finer punctures in middle and coarser punctures laterally. Metepisternum somewhat narrower than antennal club and with distinct, large punctures. Epipleura almost 0.6 times as wide as antennal club long. Abdominal ventrite 1 longest, about 1.6 times as long as hypopygidium and 2.1 times longer than each of ventrites 2-4. Hypopygidium rounded at apex. Submesocoxal line almost rectilinearly deviating from posterior edge of mesocoxal cavity ( Figs 2 , 4 ). Distance between metacoxae more than three times as great as that between procoxae, and about twice as great as that between mesocoxae.

Protibia artcuately curved, about as wide as antennal club, with rounded outer apical angle and with apical angle round ( Fig. 9 ); meso- and metatibiae almost subtriangular and slightly narrower than protibia, both with rows of dense setae along outer edge. Femora 1.8 times as wide as corresponding tibiae. Metatarsus shorter than corresponding tibia.

Male genitalia: Tegmen narrow, strongly sclerotized and rounded apically, about 4.3 times as long as wide, with short setae disposed along middle of tegmen and forming an X-like figure; also with long setae along sides and at apex ( Fig. 10 ). Penis trunk about 2.1 times as long as wide and 0.4 times long as tegmen, with apex widely rounded and with two wide apical lobes narrowed apically ( Fig. 11 ).

Female: Body size: length 2.9-3.5, width 2.1-2.8 mm. Ovipositor moderately sclerotized, gonocoxal apex acuminate ( Fig. 14 ).

Variability.

Some variation is observable in coloration and punctures. The holotype and paratypes from Chuxiong City, Zixi Mountain, and Qujing City, Yehuagou (all Yunnan Province) are subunicolorous black, while the paratypes from Dali City, Cangshan Mountain, and Qujing City, Junzi Mountain (all Yunnan Province) and from Bijie City, Shangdi Mountain (Guizhou Province) are blackish with brightly brownish elytra.

Diagnosis.

Neopallodes nigrescens can be distinguished from other species of the genus Neopallodes by its unique body color (dorsal surface blackish or with elytra brightly brownish orange), elytra with regular longitudinal rows of large punctures and not quite regular longitudinal rows of small punctures arranged alternately and tegmen with short setae forming an X-like figure. This taxon is similar to N. inermis , but differs from it in: antennal club distinctly shorter than antennomeres 2-8 combined; metaventrite with fine punctures in the middle and with large, sparse punctures laterally; tegmen with short setae forming an X-like figure; penis trunk with round apex.

Name derivation.

The specific epithet is derived from the Latin word " nigrescens " (= blackening) referring to the color of dorsal surface of most specimens.

Figures

Figures 1 - 17. Neopallodes nigrescens sp. nov. (male) 1, 3 body, dorsal 2, 4 body, ventral 5 head, dorsal 6 pygidium 7 anal sclerite, ventral 8 left antenna, dorsal 9 left profemur and protibia, dorsal 10 tegmen, dorsal 11 penis trunk, dorsal 12 ovipositor, ventral 13 mentum and inner edges of antennal grooves, ventral 14 prosternal process, ventral 15 left mandible, dorsal 16 left maxillary palpus, ventral 17 anterior part of mesoventrite, ventral 1 - 2, 5 - 17 specimen from " Yunnan Province, Chuxiong City, Zixi Mountain " 3, 4 specimen from " Yunnan Province, Dali City, Cangshan Mountain " Scale bars: 1 cm (1 - 4); 0.2 cm (5 - 12); 0.2 cm (13 - 16); 0.2 cm (17).