Stempellinella apicula Guo and Wang

Ekrem, Torbjørn, 2007, A taxonomic revision of the genus Stempellinella (Diptera: Chironomidae), Journal of Natural History 41 (21 - 24), pp. 1367-1465 : 1375-1376

Stempellinella apicula Guo and Wang

Stempellinella apicula Guo and Wang 2005, p 27 . Holotype: „ ( NU 11275 ) China: Yunnan Province, Dali County, Zhonghe Village , 26 ° 109N, 101 ° 259E, 2300 m a.s.l., light trap, 22 May 1996, X. Wang [examined].

Diagnostic characters

Stempellinella apicula can be separated from other species in Stempellinella by the following combination of characters. Adult male with broadly triangular frontal tubercles; AR ca 0.6; superior volsella somewhat rectangular with apex drawn into an anteromedially directed point; anal point long with spinulae and microtrichia between well-developed crests; gonostylus with obvious posteromedially pointed apex.

Redescription

Adult male (n 5 1). Total length 2.2 mm; wing length 1.10 mm.

Colour: pale, brown-green body colour with brown scutal stripes, postnotum, median anepisternum, epimeron and antennal pedicels; somewhat darker antepronotum; scutellum pale; halteres pale; eyes brown-red, darker ventrally.

Head ( Figure 1A, B ): eyes without dorsomedian elongation; frontal tubercle large, broad, triangular, 15 Mm long; antenna ( Figure 1B ) with 13 flagellomeres of which only 10 are easily discernible; AR (on 10 flagellomeres) 0.60; lengths of palpomeres (in Mm): 20, 22, 50, 80, 115. Clypeus about 50 Mm long with seven setae; tentorium ca 80 Mm long, 15 Mm wide; three inner verticals, two outer verticals, three postorbitals.

Thorax: scutal tubercle weak, broad; acrostichals 13; dorsocentrals 6; humerals 1; prealars 1; scutellars 7; halterals 6.

Wing ( Figure 1C ): cuneiform, 2.7 times longer than broad; VR 1.76; wing setation as in Figure 1C .

Legs ( Figure 1D ): fore tibia with 12 Mm long spur; mid and hind tibiae with wellseparated, 12–13 Mm long tibial combs, one mid tibial comb with 35 Mm long spur, one hind tibial comb with 32 Mm long spur; mid tarsus 1 without sensilla chaetica; pulvilli absent. Lengths and ratios of leg segments in Table III.

Hypopygium ( Figure 1E, F ): anal tergite 95 Mm long with transverse anal tergite band; three strong median setae at some distance from anal point base, one lateral seta, 22 apical setae; anal point 43 Mm long, basally 7 Mm broad with long, well-developed crests which end close to anal point apex; 10 small spinulae and microtrichia between anal crests; microtrichia-free area on each side of anal point base. Gonocoxite 80 Mm long; gonostylus 60 Mm long; HR 1.33. Superior volsella ( Figure 1F ) somewhat rectangular with apex drawn into an anteromedially directed point, four dorsal and two median setae on setiger, superior volsella otherwise bare; digitus absent; median volsella 30 Mm long, straight, posteromedially directed, stem simple with numerous simple ca 20 Mm long lamellae which reach two-thirds length of inferior volsella; inferior volsella 60 Mm long, slightly club-shaped, with several distal setae, dorsal surface without microtrichia.

Adult female, pupa, and larva. Unknown.

Remarks

Stempellinella apicula has been recorded only from its type locality in China ( Guo and Wang 2005). The immature stages and their habitat remain unknown, but the larvae probably construct small, straight transportable cases of sand and detritus like the morphologically similar species in Europe .

Figures

Figure 1. Stempellinella apicula Guo and Wang, male imago. (A) Head; (B) antenna; (C) wing; (D) mid and hind tibiae; (E) hypopygium; (F) superior, median and inferior volsellae.