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Paussus brancucci
| Paussus brancucci | |
|---|---|
| |
| Scientific classification | |
| Kingdom: | Animalia |
| Phylum: | Arthropoda |
| Class: | Insecta |
| Order: | Beetle |
| Suborder: | Polyphaga |
| Family: | Carabidae |
| Genus: | Paussus |
| Species: | P. brancucci |
| Binomial name | |
| Paussus brancucci Nagel, 2016
| |
Diagnosis
A dark coloured species with lighter appendages. Head dorsally with four tubercles characteristic of the P. jousselinii group sensu stricto. Antennal club elongate, dorso-ventrally compressed, narrowed between apical half and basal margin; posteriorly with subapical narrow furrow. P. brancuccii sp.nov. is unmistakeably characterized within the P. jousselinii group by the entire, uninterrupted basal margin of the antennal club with a smooth area instead of a distinctly marked deep depression or incision between the articulation to the (second and) first antennomere and the posterior basal angle. In addition, the new species is characterized by the combination of the following criteria: elytra with 3 rounded patches each, sometimes faint and difficult to see; antennal club with the apical half set with three glabrous, obtuse, sometimes weak or irregular denticles at the lower (ventral) edge of the posterior furrow; this furrow extending basally until the middle of the club; head with each of the frontal plates in front of frontal tubercle little longer than wide.
Description
Standardized body length (in dorsal view, frontal margin of head until hind margin of elytra): 5.8ñ6.9 mm; width across mid-elytra 2.1ñ2.4 mm; holotype specimen 6.8 mm, 2.3 mm Colour (Fig. 1): A dark, dull species; head, prothorax, elytra and pygidium blackish, and antennae, mouthparts, legs, abdomen, lateral and apical elytral margin, and subapical elytral flanges dark rufous-brown. Surface structure: Overall appearance dull due to very dense microgranulation on elytra, anterior and lateral parts of pronotum; head with prominent relief, rugose and densely set with small contiguous punctures; Pubescence of small yellowish, obconical to obtuse lanceolate, scaliform setae regularly set one per puncture on legs and antennae, patchy and scattered on head, pronotum, elytra; setae narrower and less scaliform on pygidum and dorsal tarsi; short, thin, curved to erect setae of the series umbilicata in umbilical punctures difficult to see, up to three set along the proximal half of the elytral lateral margin plus one on the disk next to the subapical fold. Head (Fig. 3) 1.3 times broader than long; surface of head very uneven, dull, with sharply marked contiguous punctures and microgranulation, at high magnification reminiscent of the tubular layer of a Boletus; location and shape of the four tubercles as illustrated in Fig. 3; posterior tubercle at vertex higher than the remaining ones and distinctly notched at apex; frontal suture glabrous, shining, sometimes forming a narrow groove; each of the two frontal plates in front of frontal tubercle steeply inclined towards frontal suture and little longer than wide (<1.2 times); seen from above, pair of frontal plates 1.5 times wider than long; ratio eye/gena (shortest diameter of eye between front and hind margin / shortest distance between antennal insertion and front margin of eye): 1.3 females, 1.6 males; temples projecting beyond eyes; while small subapical orifices are visible in the slit-like structures of the two lateral tubercles, no distinct aperture is detectable in the double-pore-like structure on top of the frontal tubercle; all three tubercles, however, are actually functional as gland openings because amber-coloured residues of the exudate are sometimes visible at the respective sites. Mouth parts (Fig. 4) adjacent to the underside of head; labrum transverse, frontal margin concave; palpifer (part of stipes) exposed; maxillary palpi with 2nd (third from last) palpomere longest and broadest, dilated towards apex, 1.1 times longer than wide at apex; palpiger (part of praementum of labium) exposed; terminal labial palpomere 1.6 times longer than wide, fusiform, tapering towards the well marked apex; shield-like ligula with frontal margin tapering to a rounded point with few setae, disk with low, longitudinal, medial carina. Antenna (Fig. 5): First antennomere (scape) subquadrate with cushion-like brush of dense setae at dorso-lateral angle of inner apical margin (trichome); antennal club a compressed rod with base and apical half wider than the constricted ìhandleî; posterior outer basal angle pronounced yet not extended; 5.2 times longer than wide at narrowest part of handle, 3.4 times longer than wide at apical dilatation; basal margin without trace of incision between insertion and posterior angle, often with a smooth area without punctures instead; apical half posteriorly with a furrow which extends to about the middle of the club; lower edge of furrow with three obtuse denticles without trace of apical tuft of hair; in some specimens the denticles are very week, sometimes also irregular with one or two denticles smaller or almost obliterated (Fig. 6); sometimes the denticles are completely obliterated and the lower margin of the furrow appears to be slightly irregularly undulate; upper edge of furrow slightly sinuose, obscuring three small, knoblike tubercles, located inside the furrow immediately below the margin; longitudinal carina at anterior margin of antennal club of males complete, yet less sharp in the middle; in females this carina is almost obliterated in middle; surface of club coarsely punctured, each puncture with one scaliform seta. Pronotum (Fig. 2) as long as wide, as wide as head, transversally cleft; anterior part raised, distinctly edged behind, dorsally notched and laterally angulate; anterior part slightly wider than posterior part (1.1 times); hind part distally and proximally of equal width; hind part almost double the length of fore part; trichomes of the transversal furrow of the pronotum dark yellow, not much contrasting with the black pronotum, and visibly consisting of a narrow anterior and a broader posterior part; distance between trichomes 1.3 times longer than width of each of the trichomes (when seen from above); central excavation rising towards scutellum; excavation glabrous and smooth except rugose upper end; equally rugose at both sides of median excavation; a small but distinct, glabrous and smooth oval imprint at anterior margin of hind portion of pronotum behind each trichome. Elytra dull, with microgranulation and scattered wrinkling; each elytron with 3 rounded patches at characteristic sites (Fig. 2); all 3 patches demarkated by a lack of setae, shallow depression, and slightly raised margin; all 3 patches well marked, sometimes posterior patches more faint, level with surface, or slightly larger than anterior patch.
The new species is named for the late Michel Brancucci, entomology curator at NHMB and spiritus rector and head of the project ìBeetle diversity of Laos. The specific epithet is a proper noun in the genitive case.
Distribution
China, Laos
Biology
Host ants, Pheidole, Tetramorium