Megabatrus caviceps Lobl
Creators: name: Yin, Zi-Wei
name: Li, Li-Zhen
Publisher: name: Zenodo
Year: 2015
Subjects: Biodiversity
Taxonomy
Animalia
Arthropoda
Insecta
Coleoptera
Staphylinidae
Megabatrus
Megabatrus caviceps

description: Megabatrus caviceps Löbl
(Figs 1–5)
Megabatrus caviceps Löbl, 1979: 196.
Type material examined. Holotype (Fig. 6), ♂, labeled ‘KUATUN, FUKIEN, China, 19.4.46, (TSCHUNG SEN.) (yellow label, date except the year in hand written) / Megabatrus caviceps sp. n. det. Löbl 1979 (white label, specific epithet in hand written) / HOLOTYPE (red label, printed)’ (MHNG).
Additional material examined (14 ex.). 3 ♂♂, labeled ‘ China: Guangdong, Ruyuan Hsien (♨aeθ), Nanling N.R. (mΚDאffiffiU), 24°55'57"N, 113°00'18"E, mixed forest, wood, sifted, 1220 m, 28.iv.2015, Peng, Zhou’; 2 ♂♂, 4 ♀♀, labeled ‘ China: Guangdong, Ruyuan Hsien, Nanling N.R., Laopengkeng (ϫAE½), 24°56'29"N, 113°00'27"E, mixed forest, wood, sifted, 1360 m, 29.IV.2015, Peng, Zhou’; 5 ♂♂, labeled ‘ China: Guangdong, Ruyuan Hsien, Nanling N.R., Laopengerdui (ϫAE∴k), 24°54'57"N, 113°02'10"E, mixed forest, from logs, 850 m, 03.V.2015, Peng, Zhou’ (all in SNUC).
Supplementary description. Foveal pattern. Head (Fig. 2 A–D) with punctiform, nude, and widely separated vertexal foveae located far below level of posterior margin of eyes, lacking frontal fovea; large gular foveae close in transverse depression (Fig. 3 A); pronotum (Fig. 3 B) with small lateral antebasal foveae, lacking median antebasal and basolateral foveae; lateral procoxal foveae present (Fig. 3 A); elytra lacking basal and subbasal foveae, lacking subhumeral fovea; mesoventrite (Fig. 3 C) with median foveae close in shared opening, lateral foveae forked, anterior branches as broad as posterior ones; small lateral mesocoxal foveae present; lateral metaventral foveae close; tergite IV (first visible tergite) with one pair of large basolateral foveae at lateral ends of basal depression, tergites V–VII each with one pair of small basolateral foveae; sternite IV with three pairs of basolateral foveae; sternites V–VII each with one pair of indistinct basolateral foveae.
Male (Fig. 1 A). Measurements: HL 0.97–1.00 mm, HW 1.02–1.03 mm, AnL 2.60 mm, PL 0.82–0.84 mm, PW 0.87–0.91 mm, EL 1.32–1.35 mm, EW 1.50–1.54 mm; AL 1.02–1.11 mm, AW 1.31–1.46 mm, length of aedeagus 0.55 mm. Each eye composed of about 90 facets. Head (Fig. 2 A, B), antennomere IV (Fig. 5 A), protibia (Fig. 5 B), mesotrochanter (Fig. 5 C), mesotibia (Fig. 5 D), metatrochanter (Fig. 5 E), abdomen (Fig. 4 A, B), tergites VII–VIII (Fig. 5 F, H), sternites VII–IX (Fig. 5 G, I, J), and aedeagus (Fig. 5 P–R) are illustrated for comparison with the holotype, and with the female to show sexual dimorphism.
Female (Fig. 1 B). BL 4. 27–4.36 mm. Body reddish brown, tarsi lighter in color; most part of dorsal surface covered with short setae. Head slightly transverse, HL 0.90–0.93 mm, HW 0. 97–0. 99 mm; vertex finely punctate, slightly convex at middle, with distinct median carina, with pair of small tubercles anterior to vertexal foveae; areas below antennal tubercles coarsely punctate; eyes relatively small, each composed of about 60 facets; antennae as in Fig. 1 B, AnL 2.60 mm; antennomere IV simple, not obliquely jointed with V as that in male. Pronotum similar to that in male, PL 0.87 mm, PW 0.91 mm. Elytra slightly wider than long, EL 1.38–1.41 mm, EW 1.54–1.55 mm. Metathoracic wings fully developed. All legs simple, lacking protuberance or modification. Abdomen wider than long, AL 1.09–1.18 mm, AW 1.41–1.46 mm; tergite IV (first visible tergite; Fig. 4 C) about twice as long as V at midlength, pair of oblique lateral ridges extending to 2/3 of tergal length; tergite V about twice as long as VI at midlength, and about as long as VII; tergite VII (Fig. 5 K) broadly and slightly emarginate at posterior margin; tergite VIII with round posterior margin, densely setose along margin; sternite IV (second visible sternite; Fig. 4 D) longest; V–VII (Fig. 5 L) successively shorter; sternite VIII (Fig. 5 N) evenly rounded at posterior margin, densely covered with long setae. Genital complex as in Fig. 5 O, width 0.29 mm.
Distribution. This species was previously known only from the Guadun, Fujian. The new data extend its distributional range to the Nanling Natural Reserve in northern Guangdong, ca. 550 km SW from the type locality (Fig. 6).
Biology. Adults were collected from the inside of decomposing logs during day, and at night they were observed roving on the surface of the logs. One individual was found on the surface of a decrepit wooden door. It can be assumed that Megabatrus caviceps is an active predator associated with the rotten wood. Comments. The modified head and legs of the male and the aedeagus clearly indicate that the population of Nanling is without a doubt conspecific with that of the type locality.
description: Published as part of Yin, Zi-Wei & Li, Li-Zhen, 2015, Range extension and sexual dimorphism in Megabatrus caviceps Löbl (Coleoptera, Staphylinidae, Pselaphinae), pp. 440-446 in Zootaxa 3974 (3) on pages 441-444, DOI: 10.11646/zootaxa.3974.3.11, http://zenodo.org/record/245022