Pterogrammoides Papp, 1972

Kuwahara, Gregory K., Marshall, Stephen A. & Luk, Stephen P. L., 2025, A revision of Parapterogramma Papp and Pseudopterogramma Papp, with a review of the Parapterogramma genus group of the Pacific and Indomalayan regions (Diptera, Sphaeroceridae, Limosininae), European Journal of Taxonomy 998, pp. 1-124 : 114-115

Genus Pterogrammoides Papp, 1972

Pterogrammoides Papp, 1972: 103 (masculine). Type species: Pterogrammoides baloghi Papp, 1972 , original designation.

Pterogrammoides – Papp 1989: 328 (revision, key). — Roháček et al. 2001: 216 (world catalog).

Diagnosis

In addition to the synapomorphies of the Parapterogramma genus group, Pterogrammoides is diagnosed by the following characters: distal half of the mid tibia with a single dorsal bristle, proximal half without bristles; postpedicel conical; wing very narrow with crossveins shifted towards the wing base; preabdominal sclerites reduced in both males and females. Characters of the male terminalia, such as the greatly enlarged S6–8 that contrasts with the greatly reduced tergites, stout surstylus with tooth-like ventral setae, thin and elongate postgonite, and the large ejaculatory apodeme, allow for easy identification of the genus.

Definition

Pterogrammoides is defined by the following synapomorphies: strongly reduced, almost strap-like wings with significantly reduced venation, strongly reduced mid tibial chaetotaxy (with only a single distal dorsal bristle), conical postpedicel, stout surstylus with tooth-like ventral setae, thin and elongate postgonite, greatly enlarged S6–8 contrasting with strongly reduced abdominal tergites and sternites, and enlarged ejaculatory apodeme.

Redescription

BODY. Colour light to dark brown. Length 1.1–1.4 mm.

HEAD. Yellow to brown. Frontal width 1.5× interfrontal height. Interfrontal bristles in three minute pairs; two minute lateroclinate orbital bristles, anterior orbital smaller than posterior; ocellar bristles fine and diverging; inner orbital bristle very large; postvertical bristle absent; postocellar bristle absent. Lunule small, subtriangular; face slightly bulging centrally. Vibrissa strong, vibrissal angle with subvibrissal seta; gena with several smaller setulae. Palpus small, slightly clavate, narrow with 2–3 subapical setulae. Eye with a slight notch at about level of anterior edge of frons, eye height 3.5–4.0 × genal height.

THORAX. Yellow to brown. Two large dorsocentral bristles (anterior pair just behind suture), separated by 4–5 rows of very fine acrostichal setulae. One postpronotal bristle; two notopleural bristles, anterior notopleural slightly larger than posterior; one strong supra-alar bristle; postalar bristles strong. Katepisternum with a small posterior seta. Scutellum subrectangular, with four large marginal bristles, apical pair 2.0× length of basal pair.

LEGS. Yellow to dark brown; tarsi pale. Fore and hind femora thickened. Mid tibia with no distinct anterodorsal bristles in proximal half and 1–3 dorsal bristles (one large dorsal bristle and sometimes a small anterodorsal or posterodorsal) in distal half. Ventral surface of mid tibia with a small apical bristle and two rows of stout setae in males (mid femur with two corresponding rows of strong proximoventral setae) and with a strong apical bristle in females; never with a distinct midventral bristle. Mid basitarsus without distinctly enlarged ventral setae. Hind tibia with a distinct apicoventral seta.

WING. Slightly infuscate. Elongate (length 2.5–2.6 × width) and almost parallel-sided (alar surface reduced). CS2 essentially non-existent (R 2+3 never contacts costa). R 2+3 very short, straight, petering out in membrane; R 4+5 straight, meeting costa at wing tip; costa ending at apex of R 4+5. Crossveins shifted towards wing base, about in-line with end of R 1. M 1 sometimes present as a coloured pseudovein beyond dm-m; M

4

indistinct beyond dm-m. CuA+CuP weak and sinuate. Halter pale.

MALE ABDOMEN. T2–5 and S2–4 very weakly sclerotized, uniformly setose posteriorly. S5 asymmetrical (right side slightly projecting posteriorly), broad, simple with scattered small setae and longer posterolateral setae. Synsternite 6+7 usually very large, comprising 0.2–0.3× total abdominal length, S6+7 broadly and strongly fused to S8 dorsally. Epandrium saddle-shaped and uniformly setose; cercus small, strongly fused to and indistinct from epandrium, with two long setae, cerci fused together to form subanal plate. Hypandrium V-shaped, posterolateral arms strongly fused to anteromedial apodeme but not to the anteroventral corners of the epandrium. Surstylus stout, usually subtriangular with a small, inner median lobe, posteroventrally with two enlarged tooth-like setae and anteroventrally with two smaller thorn-like setae. Postgonite relatively simple, curved or sinuate. Phallapodeme very large (projecting into 4th abdominal segment), elongate and sinuate with tall dorsal and ventral margins; basiphallus stout, boxy with a large, sclerotized, L-shaped dorsal ejaculatory apodeme ( Papp (1989) refers to this structure as the ejaculatory pump). Distiphallus stout, usually with a tubular, sclerotized base and a bulbous, membranous, apical part supported by numerous thinner sclerites.

FEMALE ABDOMEN. T2–5 and S2–5 largely desclerotized, sometimes almost indistinct. Abdomen slightly shorter than length of head + thorax. Postabdomen short, non-telescoping. T6–7 and S6–7 usually rectangular and long-setose in posterior half. T8 sometimes divided into two large, setulose, lateral sclerites. Epiproct indistinct. Cercus small. S8 usually large, microtomentose, and with several posteromedial setae. Hypoproct indistinct. Spermathecae (2+ 1 in two of the three species with known spermathecae, only one in Pt. thaii ) subspherical to elongate and ovoid, lightly grooved, stem short and membranous; accessory gland large.

Distribution

Pterogrammoides includes one species known from India, three from Papua New Guinea, and one from Thailand.

Species descriptions (in alphabetical order)