Pseudosmittia macrobrachia (Edwards)

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 : 194-195

Pseudosmittia macrobrachia (Edwards)

( Fig. 72 G, H )

Orthocladius macrobrachius Edwards, 1928: 62 .

Pseudosmittia macrobranchia (Edwards) ; Cranston & Martin 1989: 262 (misprint).

Material examined: SAMOA: Savaii , Safune, lectotype male, here designated. 12.v.1924, E. H. Bryan Jr. ( BMNH); 29 males as lectotypes ( BMNH) .

Diagnostic characters: According to Edwards (1928) the male imago is very similar to P. brevifurcata , from which it differs in being smaller in size and having fewer clypeal and prealar setae. However, among the species treated in this revision, it overlaps in measurements and general morphology with P. digitata and P. joaquimvenancioi , from which it differs in greater number of scalpellate sensilla clavata of the third palpomere, which lacks an apical projection, and in leg ratios.

Male imago (n = 10–16, except when otherwise stated)

Total length 1.31–2.02, 1.63 mm. Wing length 0.61–0.99, 0.85 mm. Total length/wing length 1.75–2.01, 1.91. Wing length/length of profemur 2.73–3.09, 2.82. Coloration brown with slightly darker vittae to fully blackish brown.

Head. AR 0.61–0.78, 0.66 (6). Terminal flagellomere 166–232, 194 µm long; no apical strong seta. Temporal setae 4–6, 5 consisting of 1–2, 2 inner verticals and 3–4, 3 outer verticals. Clypeus with 2–6, 4 setae. Tentorium 79– 111, 89 µm long, 15–21, 18 µm wide. Stipes 64–99, 82 µm long, 17–27, 23 µm wide. Palpomere lengths (in µm): 14– 22, 20; 20–32, 26; 30–63, 50; 56–88, 71; 74–127, 102. Third palpomere with 10-12 scalpellate sensilla clavata, and without apical projection.

Thorax. Antepronotal lobes reduced medially, antepronotum with 1–2, 1 lateral setae. Dorsocentrals 8–12, 10; acrostichals 2; prealars 3. Scutellum with 2–4, 4 setae.

Wing. VR 1.55–1.79, 1.71. VR 2 1.29–1.48, 1.40. Anal lobe reduced. Costal extension 22–46, 31 µm long. R 4+5 ending well proximal to apex of M 3+4; Cu 1 straight. Brachiolum with 1 seta, other veins bare.

Legs. Spur of front tibia 24–40, 34 µm long; spurs of middle tibia 15–30, 20 µm long; of hind tibia 25–36, 32 µm and 10–20, 16 µm long. Width at apex of front tibia 19–26, 22 µm; of middle tibia 21–26, 23 µm; of hind tibia 26–37, 32 µm. Comb of 10–12, 11 setae; shortest setae 13–23, 18 µm long, longest setae 24–32, 28 µm long. Lengths (in µm) and proportions of legs as in Table 44.

Hypopygium ( Fig. 72 G, H ). Anal point 24–52, 37 µm long, with lateral setae; tergite IX with 6–12, 8 setae; laterosternite IX with 2–3, 2 setae. Phallapodeme 52–71, 61 µm long; transverse sternapodeme 35–54, 47 µm long, no oral projections. Virga 29–62, 45 µm long. Gonocoxite 93–119, 108 µm long; superior volsella and inferior volsella present, reaching to 0.56–0.70, 0.62 and 0.72–0.82, 0.77 gonocoxite length, respectively. Gonostylus 42– 58, 53 µm long; megaseta 6––9, 7 µm long. HR 1.90–2.18, 2.05; HV 2.75–3.51, 3.14.

Female, pupa and larva

Unknown.

Distribution

The species is known from Samoa.

Figures

FIGURE 72. Pseudosmittia spp., male. A–E. P. nishiharaensis Sasa et Hasegawa. A—wing; B—head; C—third palpomere; D—cibarial pump and stipes; E—virga; F—hypopygium, left dorsal aspect, right ventral aspect. G, H. P. macrobrachia (Edwards); G—hypopygium, dorsal aspect; H—hypopygium, ventral aspect. (A–E from Saether 2006.)