Elacatophora thailandiana, Jałoszyński, 2020

Jałoszyński, Paweł, 2020, Four new species of the Oriental genus Elacatophora L. W. Schaufuss (Coleoptera Staphylinidae, Scydmaeninae), Zootaxa 4834 (2), pp. 264-272 : 265-267

Elacatophora thailandiana sp. n.

( Figs 1 , 5–8 )

Type material. Holotype: THAILAND (Yala Province): ♂, two labels: “ Thailand, 1.2.1991 / Banglang Nat. Park / Than To Waterfall / Than To Dist. 150m / P. Schwendinger ” [white, printed]; “ Elacatophora / thailandiana m. / P. Jałoszyński, 2020 / HOLOTYPUS ” [red, printed] ( MHNG) . Paratype: 1 ♀, same data as holotype ( MHNG) .

Diagnosis. BL <1.2 mm; pronotal antebasal transverse groove entire; antennal club composed of antennomeres 8–11 and strongly thickening distad; aedeagus in ventral view conspicuously slender, in lateral view with apical projections weakly curved dorsad, endophallic sclerites confined to basal half of capsular portion of median lobe, parameres in lateral view slender, with nearly parallel sides.

Description. Body ( Fig. 1 ) stout with flattened pronotum and elytra, light to dark brown, covered with light brown setae; BL 1.08 mm.

Head broadest at large, strongly convex and coarsely faceted eyes, HL 0.20 mm, HW 0.20 mm; vertex and frons convex, together nearly rectangular; supraantennal tubercles barely marked. Punctures on frons and vertex inconspicuous; setae sparse, long and suberect, thick bristles sparse, directed posterad and dorsoposterad. Antennae relatively short and stout, with distinctly delimited club composed of antennomeres 8–11, AnL 0.45 mm, antennomeres 1–2 each distinctly elongate, 3–5 each transverse, 6 and 7 each about as long as broad, 8–10 each strongly transverse, 11 slightly broader than 10, slightly longer than 9–10 combined, about 1.5 × as long as broad, oval and weakly asymmetrical.

Pronotum subconical, broadest at base; PL 0.28 mm, PW 0.29 mm; anterior and lateral margins nearly straight; posterior margin shallowly bisinuate; pronotal base with distinct and entire transverse groove connecting small and diffuse lateral pits, and with separated from groove lateral pair of small and indistinct impressions. Punctures on pronotal disc fine and inconspicuous; disc with long and sparse suberect setae, sides with sparse, long, thick bristles.

Elytra oval, broadest anterior to middle; EL 0.60 mm, EW 0.53 mm, EI 1.14; humeral calli weakly developed, basal impressions large and deep, nearly circular; apices separately rounded. Punctures on elytra as inconspicuous as those on pronotum; setae long, sparse, suberect. Hind wings well developed.

Legs moderately long and slender, all tibiae nearly straight.

Aedeagus ( Figs 5–8 ) in ventral view slender, drop-shaped; AeL 0.20 mm; median lobe with indistinctly demarcated, long subtriangular apical portion with rounded apex, apical projections weakly and evenly curved dorsad; endophallus in ventral view with two lateral basal bunches of needle-like sclerites flanking a shorter median group of similar sclerites; parameres long and slender, each with 2–3 apical setae.

Female. Externally similar to male, but with distinctly smaller eyes; BL 1.10 mm; HL 0.20 mm, HW 0.23 mm, AnL 0.45 mm; PL 0.28 mm, PW 0.28 mm; EL 0.63 mm, EW 0.53 mm, EI 1.19.

Distribution. Southern Thailand ( Fig. 21 ).

Etymology. Named after the country of origin.

Remarks. This is the first Elacatophora known to occur in Thailand. The only known male holotype and female paratype are the smallest specimens among all currently known species of this genus. Adults of E. thailandiana measure merely 1.08 mm (male) and 1.10 mm (female), whereas in all remaining species body length ranges from 1.18 to 3.50 mm. Only E. euconnoides Jałoszyński, 2015 , E. dissimilis ( Jałoszyński, 2004) and two species described below as new ( E. jambiana and E. indica ) are nearly as small as E. thailandiana , not reaching 1.5 mm. Comparisons given below are based on male characters.

Elacatophora thailandiana differs from E. euconnoides in proportions of the body parts; the elytra in the new species are stouter (EI 1.14 in male of E. thailandiana vs. 1.29 in male of E. euconnoides ), and the antennae are conspicuously different: in E. thailandiana the club is composed of antennomeres 8–11 and the antennomere 11 is clearly broader than 10 and nearly as long as 9–10 together, whereas in E. euconnoides the antennal club is composed of antennomeres 6–11, and the antennomere 11 is indistinctly broader than 10 and much shorter than 9–10 combined. Moreover, the aedeagus of E. thailandiana is strikingly slender and its apical projections (both ventral and dorsal plates) are weakly curved dorsad, vs. stout aedeagus in E. euconnoides with the apical projections strongly curved dorsad.

Elacatophora thailandiana differs from E. dissimilis in a stouter body (PI 0.96 and EI 1.14 vs. PI 1.15 and EI 1.24 in E. dissimilis ), antennae more strongly thickened and with more distinctly delimited clubs (in E. dissimilis antennae are conspicuously slender, weakly thickened, with indistinctly delimited clubs, and antennomere 11 is strongly elongate). The aedeagus of E. dissimilis is clearly stouter than that of E. thailandiana , and in ventral view oval, with sides in distal half evenly rounded, and not sinuate.

Elacatophora thailandiana differs from E. jambiana described below in a clearly stouter body ( Fig. 1 vs. 2), especially the head in E. thailandiana is much larger in relation to the pronotum. The antennal club in E. thailandiana is thicker in relation to the proximal flagellomeres and composed of antennomeres 8–11 vs. a slender club composed of antennomeres 6–11 in E. jambiana . The aedeagi of these species differ remarkably ( Figs 5–8 vs. 9–12), with that of E. thailandiana being extremely slender and weakly curved vs. that of E. jambiana extremely stout and strongly curved, crescent-shaped in lateral view.

Elacatophora thailandiana differs from E. indica described below in a stouter body ( Fig. 1 vs 4), antennae with the club composed of antennomeres 8–11, vs. composed of antennomeres 7–11 in E. indica , and in the aedeagus ( Figs 5–8 vs. 17–20). The median lobe in E. thailandiana is slenderer, and in ventral view the apical region is delimited only by a shallow concavity of lateral margins (i.e., the sides, convex at the level of parameral apices, become weakly concave at the base of apical projections). In E. indica , the median lobe is stouter and the apical region is abruptly delimited from the basal capsule.

Figures

FIGURE 21. Distribution of nominal Elacatophora species. Collecting locality for Elacatophora soesilae is known only as “central Java”.

FIGURES 1–4. Dorsal habitus of a paratype female (1) and holotype males (2–4). Elacatophora thailandiana sp. n. (1); E. jambiana sp. n. (2); E. kerinciana sp. n. (3); E. indica sp. n. (4).

FIGURES 5–12. Aedeagus in ventral (5, 7, 9, 11) and lateral (6, 8, 10, 12) views. Elacatophora thailandiana sp. n. (5–8); E. jambiana sp. n. (9–12).