Paussus agatae, Nagel, 2024

Nagel, Peter, 2024, The Paussus (Scaphipaussus) lanxangensis species group of Indomalayan ant nest beetles (Coleoptera, Carabidae, Paussinae, Paussini) with description of a new species, Zootaxa 5501 (3), pp. 447-457 : 448-451

Paussus agatae sp. nov.

Holotype. Female and single specimen, here designated: Dry mounted, glued to pinned card. Head and antennae with scapes detached and glued to the same card. BL 3.8 mm.

The following labels are pinned with the specimen:

Small, vertical rectangular label, black printing: ♀

White rectangular label (black handwriting): Paussus agatae sp. nov.

White rectangular label (black handwriting): NHM Basel

Red quadrat label (black handwriting): Paussus agatae sp. nov., P. Nagel 2021 HOLOTYPUS

Two white rectangular labels, black printing, as shown in Fig. 1 .

Depository: NMB

Type locality and additional information: Northwestern Laos, Bokeo Province, Houaixai district, 5km W of Ban Toup, Bokeo Nature Reserve , 500–700 m a.s.l., 20°27-28‘N 100°45’E, 4–18 May 2011, leg. Natural History Museum Basel, Laos 2011 expedition Michel Brancucci, Michael Geiser, David Hauck, Zdeněk Kraus, Any Phantala, Elawan Vongphachan .

Habitat: Primary lowland evergreen dipterocarp forest, patches of secondary forest and small agricultural areas ( Geiser & Nagel 2013). Captured in a flight interception trap, i.e., the specimen was probably flying at low height above ground.

Etymology: Named for Mrs. Agata Luka Stan, Research Institute of Organic Agriculture (FiBL), Frick, Switzerland, who, on behalf of the Natural History Museum of Basel, Switzerland, and with support of the foundation Pro Entomologia, Basel, searched for months many jars full of preserved tiny arthropods from flight interception traps. The specific epithet is a proper noun in the genitive case, derived from the given name “Agata”.

Description ( Figs 2 , 3 )

Body yellowish-brown with the following areas infuscate (dark brown to blackish, not sharply delimited):disc of elytra, lateral flanks of pronotum, frontal margin of head, dorsal and ventral disc of antennal clubs, external antennomeres 1 (scapes), proximal two thirds of all femora. Glossy parts restricted to posterior parts of vertex cavity, central part of transverse pronotal furrow, pygidial disc, and tibiae.

Dorsal head 1.3 times wider than long, almost as wide as the pronotum, temples large, evenly rounded towards neck constriction, not projecting beyond eyes, frontal margin sinuate. Dorsal head with rough surface, coarsely granulated, and with four deep excavations. Frontal excavation carving the frontal margin. Two laterodorsal excavations with coarse surface. Central posterior excavation indicating a stigmatoid fusion of ancestrally free lateral plate-like structures. Basal surface of the latter excavation smooth, even, impunctate and glossy.

Antennal club as shown in Fig. 2 (female! male unknown). Dorso-ventrally little compressed, 1.9 times longer than wide at dorsal view with anterior (inner) margin slightly and evenly convex and posterior (exterior) margin slightly and evenly emarginate. At hind view, antennal club excavated at little more than the proximal half of its length. At dorsal view, posterior basal angle little pronounced, forming a short, rounded projection.

Mouthparts (cf. Robertson & Moore 2016) as shown in Fig. 3 . Maxillary palpomere III (penultimate palpomere) not distinctly wider than following (terminal) palpomere IV. Length of maxillary palpomere II (third from last) 0.26 mm. The labial palpomeres are not distinctly wide, flattened and spade-shaped. The terminal labial palpomeres are elliptic, with distal two thirds tapering. Tip diminutive. Lateral lobes of mentum broadest at basis, lateral margins slightly sinuate, not straight. Width/length ratio of gula at narrowest point 0.4 (Character 15, state S 2 in Robertson and Moore (2016), Table S2. N.B.: here measured at original detached head capsule at plan view of posterior part, not taken from Fig. 3 ).

Pronotum slightly wider than long (1.13 times), divided by a deep transverse furrow, equipped with one small trichome brush each at both lateral ends. Frontal portion laterally projecting with angles broadly rounded. Hind portion with two large, blunt, central tubercles set left and right of the middle. Medial oblong depressions at fore and hind part shining.

Legs with tibiae moderately compressed, widened towards distal margin, especially at hind tibiae. Exterior margin of all tibiae rounded, outer apical angles rounded, not produced. Tibiae without terminal spurs. Tarsi with tarsomeres 1 to 4 subequal, ventrally with scattered bristles (adhesive pads absent). Infuscate section of dorsal hind femora with transverse, slightly curved to straight, densely arranged, narrow, low and blunt ridges (see Fig. 2 ). This structure is larger and independent of the proximally adjoining small area of the stridulatory file.

Stridulatory organ: Basically as shown for Gen. Paussus in general ( Di Giulio et al. 2014). The stridulatory file is a well demarcated, finely and densely ridged small area at the basal part of the dorsal femur. The micro-ridges of the file are orientated longitudinally along the axis of the femur, as usual. The scraper appears to be different from the exemplary Paussus favieri Fairmaire, 1851 (cf. Di Giulio et al. 2014) with regard to the low number of the spines and their wider spacing (less than 10 in P. agatae sp. nov. versus 25–30 in P. favieri , loc.cit., p. 695). One has to consider, though, that these characters are highly variable in Paussus ( Di Giulio et al. 2014, p. 695) , that the study of the organ was technically difficult and the details given here are, hence, of limited significance.

Scutellum with apex rounded, finely shagreened.

Elytra: Dorsal disc with dense punctuation, distance between neighboring punctures ca. 1 puncture at minimum. Pubescence of medium length, proximally upright to distally curved setae.

Hind wings visible through cleft of the dehiscent elytra, fully developed.

Pygidium excavated, bottom glossy, dorsolateral margins at both sides explanate, upturned, and bent towards the disc. Marginal trichome fringe absent.

Measurements: Body length from anterior margin of head to apex of elytra 3.8 mm. Elytra 1.7 times as long as wide (= length from anterior margin of shoulder to apex divided by total width of both elytra). Antennal club 0.84 mm long, twice as long as wide.

Figures

FIGURE 1. Original labels (20 X 10 mm each) pinned with holotype specimen of P. agatae sp. nov..

FIGURE 2. Paussus agatae sp.n., female holotype, habitus, dorsal view with pygidium artificially shown at plan view (originally strongly declined). Femora and tibiae of right and left side are shown at broadest and narrowest view respectively. Scale 1 mm. Illustration: Armin Coray, Basel.

FIGURE 3. Paussus agatae sp. nov., female holotype, head, mouthparts, ventral view. Inset: Left maxillary palpomere II, ventral view, slightly distorted to show broadest view, with emarginate mesal margin and slightly convex outer margin. Scale 0.5 mm. Illustration:Armin Coray, Basel.