Paramerina fragilis (Walley)

Saether, Ole A., 2011, Notes on some tanypods from Lake Winnipeg, Manitoba, Canada (Diptera: Chironomidae), Zootaxa 3069, pp. 26-42 : 38-40

Paramerina fragilis (Walley)

( Fig. 8 B–F)

Material examined. CANADA: Manitoba, Lake Winnipeg, Hecla Island, light trap, 1 male, 24.viii. 1971, M.P. McLean ( CNC).

The male is characterized by having faintly banded wings, tergite II and V light colored, LR1 of about 0.79, dorsocentrals bi-triserial, and, in the present specimen, the nearly complete lack of any inferior volsella on the gonocoxite.

Male (n = 1). Total length 3.02 mm. wing length 1.76 mm. Total length/wing length 1.71. wing length/profemur 2.40. T I, II, V and IX pale, with slight infuscation in anterior half; other tergites with basal 2/3 brown. Wing with faint banding.

Head. AR 1.51. Temporals 13. Clypeus with 26 setae. Cibarial pump, tentorium, and stipes as in Fig. 8 B. Tentorium 167 µm long. Palp lengths (in µm): 38, 67, 186, 158, 300.

Thorax ( Fig. 8 C). Antepronotum with 4 setae. Dorsocentrals 45, double to triple, including 14 humerals; acrostichals 43; prealars 15; supraalar 1. Scutellum with 23 setae.

Wing ( Fig. 8 D). VR 0.89. Brachiolum with 2 setae, R with 70 setae, R1 with 62 setae, R4+5 with 98 setae. Squama with 25 setae.

Legs. Spur of front tibia ( Fig. 8 E) 42 µm long, spurs of middle tibia ( Fig. 8 E) 54 µm and 32 µm long, of hind tibia ( Fig. 8 E) 58 µm and 24 µm long. Width at apex of front tibia 44 µm, of middle tibia 43 µm, of hind tibia 47 µm. Tarsal segments of p2 and p3 lost. Lengths and proportions of front leg as in Table 2. Femur of p2 834 µm long, of p3 736 µm long. Tibia of p2 748 µm long, of p3 975 µm long.

fe ti ta1 ta2 ta3 ta4 ta5 LR BV SV p1 736 859 681 380 245 190 98 0.79 2.34 2.49 Hypopygium ( Fig. 8 F). T IX and laterosternite IX without setae. Phallapodeme 117 µm long. Gonocoxite 216 µm long, nearly without any sign of a inferior volsella; gonostylus 140 µm long. HR 1.54, HV 2.15.

Remarks. This male appear to belong to P. fragilis (Walley) ( Roback1971: 271) in the abdominal pattern, wing pattern and high LR1. However, the hypopygium of P. fragilis ( Roback 1971 fig. 520) has a very well-developed inferior volsella on the gonocoxite, while this specimen has only a faint indication of a lobe, i.e. about as in P. smithae (Sublette) ( Roback 1971 fig. 528) and P. okigenga (Sasa) ( Niitsuma et al. 2011 fig. 17). P. o k i g e n g a also has the same abdominal pattern, but is without a wing pattern and has a lower antennal ratio. According to B. Bilyj (pers. comm.), however, the “inferior volsella” is a flap or even a lobe created as a slide preparation artifact. Bilyj has mounted long series of P. fragilis , but never found the basal lobe as projecting as the one shown by Roback (1971 fig. 520).

Distribution. The species is known from the Northwest Territories to Quebec and British Columbia to Quebec and Massachusetts, Oregon and Virginia ( Bilyj 1984: 666, Oliver et al. 1990: 13, Ashe & O’Connor 2009: 190).

Figures

FIGURE 8. A — Paramerina smithae (Sublette), male, cibarial pump, tentorium and stipes. B – F, Paramerina fragilis (Walley), male; B — cibarial pump, tentorium and stipes; C — thorax; D — wing; E — apex of tibiae; F — hypopygium.