Hydrosmittia setavena (Saether) Ferrington Jr & Saether, 2011

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 : 116-117

Hydrosmittia setavena (Saether) comb. n.

( Fig. 40 )

Pseudosmittia setavena Saether, 1969:144 .

Material examined: CANADA: British Columbia, small mountain stream along road to Takkakaw Falls near Field , holotype male, 12.vii.1967, A. L. Hamilton & O. A. Saether ( CNC No 10,004) .

Diagnostic characters: The low AR of about 0.34 combined with the low inferior volsella and the lateral spinules of the virga apparently occurring on a sclerotized structure will separate the male imago from other species of the group.

Male imago (n = 1)

Total length 2.12 mm. Wing length 1.31 mm. Total length/wing length 1.61. Wing length/length of profemur 3.36. Coloration brownish black.

Head ( Fig. 40 B ). AR 0.34. Terminal flagellomere 149 µm long. Temporal setae 5, consisting of 2 inner verticals and 3 outer verticals. Clypeus damaged. Cibarial pump and stipes as in Fig. 40 D . Tentorium 117 µm long, 21 µm wide. Stipes 105 µm long, 27 µm wide. Palpomere lengths (in µm): 23, 37, 78, 62, 112. Third palpomere ( Fig. 40 C ) with 1 lanceolate sensillum clavatum.

Thorax. Antepronotum with well developed median lobes and 2 lateral setae. Dorsocentrals 8, acrostichals 2, prealars 3, supraalar seta absent. Scutellum with 6 setae.

Wing ( Fig. 40 A ). VR 1.46. Anal lobe projecting. Costa not extended. R 4+5 ending proximal to apex of M 3+4; Cu 1 sinuate. Brachiolum with 1 seta, R with 3 setae, R 4+5 with 1 seta, other veins bare.

Legs. Spur of front tibia 26 µm long, spurs of middle tibia both 24 µm long, of hind tibia 34 µm and 11 µm long. Width at apex of front and middle tibia both 24 µm, of hind tibia 34 µm. Comb of 14 setae, 21–32 µm long. Lengths and proportions of legs as in Table 21.

Hypopygium ( Fig. 40 F ; Saether 1969, fig. 80). Anal point 25 µm long, extreme apex free of microtrichia; tergite IX with 16 setae; laterosternite IX with 4 setae. Phallapodeme 75 µm long; transverse sternapodeme 71 µm long, with relatively well developed oral projections. Virga ( Fig. 40 E ) consisting of 23 µm long median spine with lateral spinule groups and about 41µm long sclerotized structure at different level carrying spinules. Gonocoxite 146 µm long; superior volsella absent; inferior volsella low and accessory lobe present, reaching to 0.55 and 0.75 gonocoxite length, respectively. Gonostylus 66 µm long; megaseta 13 µm long. HR 2.21, HV 3.20.

Female, pupa and larva

Unknown.

Distribution

The species is known only from the type locality, a mountain stream in British Columbia .

Figures

FIGURE 40. Hydrosmittia setavena (Saether) comb. n., male. A—wing; B—head; C—third palpomere; D—cibarial pump and stipes; E—virga; F—hypopygium, left dorsal aspect, right ventral aspect.