Parapsectra chionophila ( Edwards, 1933 )

Giłka, Wojciech & Jażdżewska, Natalia, 2010, A systematic review of the genus Parapsectra Reiss (Diptera: Chironomidae: Tanytarsini) with description of a new species from Poland, Zootaxa 2350, pp. 1-21 : 4-8

Parapsectra chionophila ( Edwards, 1933)

( Figures 2 , 12–14 , 34, 35 )

Material examined. FINLAND. Sarmitunturi near Vanhapää (Inari distr.), c. 13 km west of the Russian border, 3 June–27 August 2004, Malaise trap, 6 males, JS. NORWAY. Kvitblik near Fauske, 7 July 2006, sweep net, 1 male, WG.

Diagnostic description. Adult male (measurements in Tables 2 and 8).

Colouration. Generally dark. Antennal pedicel, scutal stripes, postnotum, sternum and legs dark brown to fuscous; antennal flagellum, head capsule, scutellum, haltere, ground colour of thorax and abdomen including hypopygium olive-brown to dark brown; wing with brownish undertone, with C, M and radial veins distinctly darker, brown. Head. Antenna with 13 well separated flagellomeres. Frontal tubercles rarely present, formed as tiny swellings. Third palpomere longer than fourth. Wing. Sc, M, R2+3, very short proximal section of M1+2 and 1/3 proximal part of Cu bare, remaining veins with macrotrichia. FCu under RM. RM very short. Membrane below An with sparse macrotrichia. Anal lobe of wing strongly reduced ( Fig. 2 ). Legs. Spur of fore tibia straight, 4–15 μm long, often reduced or absent. Combs of mid and hind tibiae slightly separated or fused, each tibia with 30–32 teeth 10–15 μm long (mid leg) and 30–35 teeth 14–16 μm long (hind leg).

Hypopygium. Gonostylus long, widest in half length, subapically narrowed, tapering to blunt tip. Anal tergite with long separated bands of V-type; lateral teeth absent; anal point broad at base, very short and apically rounded, bearing thin crests; microtrichia-free area surrounding base of anal point small ( Fig. 12 ). Superior volsella variable in shape, usually with convex and broadly rounded anteromedian margin and apex; digitus stout but short, reaching half length of superior volsella, apically rounded, variable in shape; Micropsectra -seta placed on tall cylindrical tubercle ( Figs 12, 13 ). Median volsella short, with stumpy stem bearing c. 20 small spoon-shaped lamellae placed in 2–3 irregular rows apically ( Fig. 14 ). Inferior volsella short but stout, slightly bent at base, with distinctly swollen head-like distal half ( Figs 12 , 34, 35 ).

Adult female: Edwards (1933); pupa and larva: unknown.

Discussion. The adult male of Parapsectra chionophila can be separated from other species of the genus by its superior volsella with convex and usually broadly rounded anteromedian margin and/or apex ( Figs 12, 13 ), the stumpy stem of the median volsella ( Fig. 14 ), the inferior volsella with swollen head-like distal part ( Figs 12 , 34, 35 ), and by the very short wing vein RM ( Fig. 2 ). Although the colouration varies greatly in most of the Tanytarsini , the dark brown/fuscous body of the adult male of P. chionophila seems to be a stable diagnostic feature. Due to the characters discussed (see above and taxonomic remarks), P. chionophila resembles P. bumasta and P. nana .

P. chionophila has been so far recorded from Britain ( Edwards 1933), Germany ( Reiss 1971), and Finland ( Paasivirta 2009). This poorly known species is presumed to be a cold-adapted stenothermic inhabitant of springs, brooks, moorland pools and peat bogs. The specimens examined in this study were collected at sites located above 67°N, from spring brooks and small lakes, together with P. nana ( Finland) , and from a temporary peat pool, together with P. styriaca ( Norway) .

Figures

FIGURES 1 – 4. Wing of male. 1: Parapsectra bumasta sp. n., 2: P. chionophila, 3: P. m e n d l i, 4: P. nana.

FIGURES 12 – 14. Parapsectra chionophila, male. 12: hypopygium, 13: superior volsella and digitus (variation), 14: median volsella (magnified x 3 in comparison with hypopygium).

FIGURES 32 – 41. Hypopygial inferior volsella and inner margin of coxite. 32, 33: Parapsectra bumasta sp. n.; 34, 35: P. chionophila; 36, 37: P. m e n d l i; 38: P. nana; 39: P. styriaca; 40: P. uliginosa; 41: P. wagneri.

Tables

TABLE 2. Length (μm) of leg segments of male Parapsectra chionophila.

fe	ti	ta1	ta2	ta3	ta4	ta5
p1 730–770 (755)	545–595 (580)	675–690 (685)	360–370 (365)	280–290 (285)	185–195 (190)	90–100 (95)
p2 700–750 (720)	640–670 (650)	285–330 (310)	175–200 (190)	140–150 (145)	90–105 (100)	75–90 (80)
p3 840–920 (870)	765–825 (790)	480–520 (505)	300–340 (325)	235–255 (245)	125–145 (140)	90–100 (95)