Benthalia brunneipennis (Johannsen)

Saether, Ole A., 2012, The Chironomus group (Diptera: Chironomidae) in Lake Winnipeg, Canada, Zootaxa 3275, pp. 1-19 : 15-16

Benthalia brunneipennis (Johannsen)

( Fig. 8 A, B)

Chironomus brunneipennis Johannsen, 1905: 205 .

Tendipes (Einfeldia) brunneipennis (Johannsen) , Townes 1945: 111.

Benthalia brunneipennis (Johannsen) , Martin 2012.

Material examined. Lake Winnipeg light traps: Pine Dock, 3 males, 10.vii. 1969.

Diagnostic characters. The adult male is characterized by its brown thorax, abdomen and haltere knob; large frontal tubercles; strongly spatulate anal point and pediform basal part of superior volsella.

Adult male (n = 3, except when otherwise stated)

Total length 5.76–6.45 mm. Wing length 2.84–3.10 mm. Total length/ wing length 1.96–2.08. Wing length/ length of profemur 2.67–2.81. Coloration brown with blackish brown vittae. Also abdomen and haltere knob brown.

Head. AR 2.81–2.98. Temporals 30–35 (2). Clypeus with 19–22 setae. Tentorium 210–245 µm long. Stipes 170–220 µm long. Frontal tubercles 41–50 µm high, 22–23 µm wide, about as in Shilova (1980 fig. 8A2). Palp lengths (in µm): 50–64, 58–68, 168–183, 185–196, 283–303.

Thorax. Antepronotum bare. Dorsocentrals 13–18, acrostichals absent, prealars 4–5, supraalar 1. Scutellum with 15–21 setae.

Wing. VR 1.08–1.10. Brachiolum with 2 setae, R with 9–11, R4+5 with 2–5 setae. Squama with 21–27 setae.

Legs. Sensilla chaetica 23–31 at 0.36–0.40 to 0.88–0.94 of ta1 of p2; 17–27 at 0.34–0.44 to 0.86–0.94 of ta1 of p2. Lengths and proportions of legs as in Table 2.

fe ti ta1 ta2 ta3 ta4 p1 1061–1104 859–920 1594–1693 711–736 595–607 485 p2 1135–1178 1024–1085 595–656 313–331 227–239 129–135 p3 1202–1288 1257–1374 920–1006 454–491 350–380 172–196 continued.

ta5 LR BV SV BR p1 178–190 1.83–1.90 1.79–1.86 1.18–1.23 2.4–2.7 (2) p2 86–98 0.57–0.60 3.63–3.64 3.45–3.69 2.8–2.8(2) p3 110–129 0.71–0.73 3.03–3.17 2.65–2.74 3.6–4.1 (2) Hypopygium ( Fig. 8 A, B). Tergite IX with 30–36 setae, laterosternites IX each with 4 setae. Phallapodeme 132–154 µm long. Transverse sternapodeme 75–100 µm long. Anal point 25–26 µm wide at apex, 8–14 µm wide in middle. Gonocoxite 231–237 µm long, base of superior volsella pediform, gonostylus 262–272 µm long. HR 0.85–0.89, HV 2.15–2.38.

Remarks. This species is closely related to B. natchitocheae Sublette (Sublette 1964: 124) , but differs in the larger wing length, lower LR1, and in the shape of the enlarged base of the superior volsella.

Figures

FIGURE 8. Hypopygium. A, B: Benthalia brunneipennis (Johannsen). C: Chironomus (Lobochironomus) sp.