Pseudostilobezzia Wirth & Ratanaworabhan, 1973

Borkent, Art & Grogan, William L., 2024, A new species of Pseudostilobezzia Wirth & Ratanaworabhan (Diptera: Ceratopogonidae) from Vietnam, Zootaxa 5448 (1), pp. 128-134 : 129-130

Pseudostilobezzia Wirth & Ratanaworabhan

Pseudostilobezzia Wirth & Ratanaworabhan, 1973: 177 . Type species: Pseudostilobezzia macclurei Wirth & Ratanaworabhan , by original designation.

DIAGNOSIS: Female adult: the only genus of Ceratopogonidae with an elongate claw and basal tooth nearly or equal in length to the foretarsomere 5 and a short claw (with basal tooth) on the mid- and hind tarsomeres 5 ( Figs. 1D–F ). Male, pupa and larva: unknown.

DESCRIPTION: Female adult: Head capsule: with or without transverse sulcus; frons extending from vertex to frontoclypeus; vertex with single seta located medially; posterior tentorial pit separated from postoccipital ridge by very narrow gap; antennal flagellomere 13 tapering gradually to apex; antennal scape with dorsomedial projection, with setae; antennal flagellum without sensilla coeloconica; frontoclypeus a single unit (no transverse suture); frontoclypeus dorsolaterally connected to eye by narrow bridge of cuticle; labrum apically bifid, with apical pegs directed ventrolaterally, small lateral teeth; base of labrum with 2 sensilla (on each side); mandible with 7–8 coarse teeth; mandibular arm originating on ventral margin of eye, articulating with base of mandible near apex of frontoclypeus; cardo and/or stipes fused medially; apex of cardo abutting but separate from posterior tentorial pit; with five palpal segments; palpal segment 3 with capitate sensilla arranged on surface or in small, round pit; prementum medial suture forked dorsally; anterior cervical sclerite triangular. Thorax: antepronotum with very slender transverse band medially; basisternal ventrolateral projection, from anterior view, broad, tapering to point; proepisternum, basisternum separate; lateral arm of prosternal apophysis of more or less constant width; postpronotum triangular; scutum with acrostichal setae, dorsocentral setae present, without modification on posteromedial margin, with scutal suture situated anterior to group of prealar setae, with three ventrally directed apodemes arising from well-separated bases, distinctly separated from one another; paratergite without setae; anterior anepisternum with dorsal point of suture posterior to anterior spiracle, with posterior margin more or less evenly curved, without setae; with broad anepisternal cleft, paratergite slender; anapleural suture short, extending to posterior margin of anepisternal cleft or just short of it; katepisternum without setae; katepisternal suture present, extending to anterior margin of katepisternum. Wing: length = 1.13–1.20 mm; margin with one or more costal setae set apart basal to level of the arculus; with 2 radial cells (r 1, r 2), first radial cell rhomboidal to elongate; radial vein with single seta just distal to the arculus, set apart from more apical setae on radial vein; with about four setae near apex of R 3 (observed only with P. curtitarsus ); without R 4+5; r-m moderately long; M 1, M 2 forking beyond crossvein r-m, with petiolate base; without or few macrotrichia restricted to apex of wing; microtrichia forming minute to somewhat elongate spicules, more or less evenly spaced. Legs: ratio of foretibia length/ hind tibia length 0.86–0.87; trochanter of fore-, midleg each with pair of thick, contiguous setae; forefemur slender, without ventral spines; hind femur with only slender or stout setae; midtibia lacking spur, with simple subapical setae; hind tibial comb with 6–7 spines; foreleg tarsal ratio (Ta1/Ta2)/ hind leg tarsal ratio 0.82–1.13; midtarsomere 1 without palisade setae; hind tarsomere 1 with two complete, at least partial third row of palisade setae, hind tarsomere 2 with (or without? not reported for P. wirthi , P. macclurei ) row of palisade setae; hind tarsomere 1 2.22–3.04 times longer than tarsomere 2; foretarsomere 5 nearly equal in diameter to midtarsomere 5; tarsomeres 4 cordiform; tarsomeres 5 with ventral setae; empodia absent; each leg with single claw and elongate tooth on fore-and midlegs, short or elongate tooth on hind claw. Abdomen: tergite 1 with dorsolateral longitudinal ridge; pigmentation of segments 7–10 more or less uniform; without tergal apodemes, eversible sacs; tergites 6–8 progressively shorter; sternites 7–8 similar in length, each shorter than sternite 6; sternite 8 with elongate, posteriorly directed, straight setae, more or less evenly spaced; sternite 8 with posteromedial cleft moderately U-shaped; without dorsally directed slender apodeme arising from posterior margin of sternite 8; sternite 9 with more laterally placed, elongate, slightly curved setae, directed posteriorly or posterolaterally; tergite 9 entire, undivided medially; without genital fork; sternite 9 discontinuous medially, forming two well-developed, expanded halves; with unmodified hypogynial valve; with more anteriorly placed hypoproct setae (not two posterior ones) tapering to, at most, a gently curved apex; with 3 spermathecae, 2 well-developed, one significantly smaller.

Eggs (in vivo): very elongate, slender.

Male, pupa, larva: unknown.

Figures

FIGURE 1. Structures of female Pseudostilobezzia curtitarsus. A. Head capsule, in anterior view. B. Left palpus, in anterior view. C. Antenna. D. Foretarsomeres 2–5. E. Midtarsomeres 2–5 (scale as in D). F. Hind tarsomeres 2–5 (scale as in D). G. Foreleg. H. Midleg (scale as in G). I. Hind leg (scale as in G). J. Thorax, lateral view. K. Wing. L. Apex of abdomen, in ventral view.