Pseudosmittia setiforceps (Tokunaga)

Ferrington Jr, Leonard C. & Saether, Ole A., 2011, A revision of the genera Pseudosmittia Edwards, 1932, Allocladius Kieffer, 1913, and Hydrosmittia gen. n. (Diptera: Chironomidae, Orthocladiinae) 2849, Zootaxa 2849 (1), pp. 1-314 : 218-220

Pseudosmittia setiforceps (Tokunaga)

( Fig. 84 A, B )

Smittia setiforceps Tokunaga, 1964: 519 .

Pseudosmittia setiforceps ( Tokunaga) ; Cranston & Martin 1989: 262, as synonym of Pseudosmittia brachydicrana (Edwards) . Material examined: PALAU (BELAU): Holotype male, Babelthuap Island , Ngiwal, at light, 19.iii.1957, C.C. Sabrosky ( USNM); allotype female, Koror Island, at light, C.C. Sabrosky ( USNM).

Diagnostic characters: The species differ from P. brachydicrana by having a lower LR 1 (about 0.48 as opposed to 0.55), postcubital fork ( Fig. 84 A ), slightly sinuous Cu 1, better developed anal lobe, gonocoxite ( Fig. 84 B ) more produced beyond base of gonostylus, and the comb of about 10 setae on the posterior dorsal side of the gonocoxite lamellate. The female imago has a long costal extension nearly reaching wing apex, an LR 1 of about 0.42, and the posterior extensions of the gonocoxite is not extending past tergite IX.

The type specimens are not in a shape to allow for accurate measurements, but the description by Tokunaga

(1964: 519) can be reiterated and supplemented.

Male imago (n = 1)

Total length about 1.74 mm. Wing length 0.93 mm (1.07 in Tokunaga is total wing length), width 0.29 mm. Total length/wing length 1.87. Wing length/length of profemur 2.38. Coloration yellow with brownish vittae and markings, legs pale brownish, abdomen brown, basal tergites widely yellow, hypopygium yellowish brown.

Head. AR 0.87. Terminal flagellomere about 270 µm long, no apical strong seta. Temporal and clypeal setae not measurable. Tentorium 95 µm long, 15 µm wide. Stipes not measurable. Approximate lengths of palpomeres (in µm): 15, 24, 57, 63, 90.

Thorax. Antepronotal lobes reduced medially, other details not measurable.

Wing ( Fig. 84 A ; Tokunaga 1964 fig. 5g). VR 1 1.69, VR 2 1.26. Anal lobe relatively well developed. Costa not extended. R 4+5 ending proximal to apex of M 3+4; Cu 1 slightly sinuous. Brachiolum with 1 seta, other veins bare.

Legs. Spurs, apical width of tibiae, and hind tibial comb not measurable, but probably only one. spur on middle tibia. long. LR 1 0.47. Front femur about 390 µm long, front tibia about 468 µm long.

Hypopygium ( Fig. 84 B ; Tokunaga 1964 fig. 6b). Anal point absent, tergite IX with about 6 setae; laterosternite IX with about 4 setae. Phallapodeme 55, transverse sternapodeme 45 µm long, no oral projections. Virga 18 µm long. Gonocoxite 148 µm long, extending 15 µm past attachment of gonostylus, with comb of 10 lamellate nearly 2 µm wide setae; inferior volsella flared and free posteriorly, reaching to 0.83 gonocoxite length. Gonostylus 63 µm long attenuate, megaseta 7 µm long; HR 2.34; HV about 2.75.

Female imago (n = 1)

Total length 1.09 mm. Wing length 0.75 mm (0.81 in Tokunaga is total wing length), width 0.25 mm. Coloration paler than in male with scutal vittae not distinctly defined, abdomen fuscous pale brown, basal segment yellow, circus yellow.

Head. AR about 0.35. Approximate lengths of flagellomeres (in µm): 54, 53, 54, 48, 84. Apical antennal seta not observed. Temporal and clypeal setae, tentorium and stipes not measurable. Palpomere lengths (in µm) according to Tokunaga: 12, 14, 27, 30, 48. Sensilla clavata not measurable. Coronal suture not measurable.

Thorax. Antepronotals not measurable. Dorsocentrals, Acrostichals, and prealars not measurable. Scutellum with 5 setae.

Wing. Anal lobe weak. Costal extension produced as long R 1, ending slightly before apex of wing,. Other details not clear.

Legs. Spurs, width at apex of tibia, and hind tibial comb not measurable. LR 1 about 0.42 Front femur about 215 µm long, front tibia about 267 µm long. Relative lengths of hind tarsi according to Tokunaga as: 41, 16, 21, 9.5, 11.5.

Genitalia. Tergite IX apparently slightly divided. Gonocoxite at least not strongly extended. Cercus about 42 µm long. Other details not measurable.

Pupa and larva

Unknown.

Distribution

The species is known from Palau only.

Figures

FIGURE 84. Pseudosmittia spp., males. A–B. P. setiforceps (Tokunaga), male. A—male wing; B—hypopygium, left dorsal aspect, right ventral aspect. C–H. P. brachydicrana (Edwards), male. C—wing; D—head; E—third palpomere; F—cibarial pump; G—virga; H—hypopygium, left dorsal aspect, right ventral aspect.