Demeijerea spinulata, Saether, Ole A., 2011

Saether, Ole A., 2011, Glyptotendipes Kieffer and Demeijerea Kruseman from Lake Winnipeg, Manitoba, Canada, with the description of four new species (Diptera: Chironomidae), Zootaxa 2760, pp. 39-52 : 40-42

Demeijerea spinulata sp. n.

( Fig. 1 A–C)

Type material. Holotype male, CANADA: Manitoba, Lake Winnipeg, 3 km off McCreary Island, 15.vii. 1969, P.S.S. Chang ( CNC). Paratype: Old Fishing Dock, 1 male, 16.vi. 1971, E. Johnson & M. Roberts.

Diagnostic characters. The male imago is characterized by a pale greenish coloration with pale orange-brown markings, an AR of about 3.5, distinct frontal tubercles, angular corners at each side of antepronotum, about 14 sensilla chaetica on ta1 of p2, a distinctly spatulate anal point, and weak apical spines on the superior volsella.

Etymology. From Latin, spinula, small thorn, and -atus, equipped with, referring to the weak apical spines on the superior volsella.

Description. Male imago (n = 1–2)

Total length 7.76–8.22 mm. Wing length 3.92–4.30 mm. Total length/wing length 1.91–1.98. Wing length/ length of profemur 2.67–2.75. Coloration pale greenish with pale orange-brown markings.

Head. AR 3.49. Temporals 25–29. Clypeus with 27–34 setae. Tentorium 280–290 µm long. Stipes 236–260 µm long. Frontal tubercles ( Fig. 1 B) 19–35 µm long, 18 µm wide. Palpomere lengths (in µm): 66–90, 83–88, 251– 272, 212–252, 356–408.

Thorax ( Fig. 1 A). Antepronotum bare, corners angular. Dorsocentrals 30–36, acrostichals absent, prealars 7– 10. Scutellum with 29–32 setae.

Wing. VR 1.01–1.02. Brachiolum with 2–4 setae, R with 15–16, R1 with 19–22, R4+5 with 14–17 setae. Squama with 30–32 setae.

Legs. Sensilla chaetica 14 at 0.27–0.74 of ta1 of p2, none on p3. Lengths and proportions of legs as in Table 1.

fe ti ta1 ta2 ta3 ta4 ta5 LR BV SV BR p1 1468–1563 1458–1547 2202 1093 790 639 252 1.42 1.92 1.41 — p2 1715–1807 1656–1698 1009 605 454 303 160 0.59 2.97 3.48 2.9 p3 1833–2007 1981–2101 1345 841 639 370 168 0.64 2.71 3.06 5.7 Hypopygium ( Fig. 1 C). T IX with 30–44 setae, including 4–8 oromedian setae; laterosternites IX each with 4– 5 setae. Phallapodeme 153–193 µm long. Transverse sternapodene 42–53 µm long. Anal point 140–156 µm long, distinctly spatulate. Gonocoxite 325–366 µm long, superior volsella with small apical spines; gonostylus 246–252 µm long. HR 1.32–1.45, HV 3.15–3.26.

Remarks. This species is close to Demeijerea abruptus ( Townes) (Townes 1945:138) and D. obreptus ( Townes) (Townes 1945:139) . It combines the AR of Demeijerea obreptus with the angular antepronotum of D. abruptus , while the frontal tubercles vary between the large type of D. abruptus and the smaller one of D. obreptus . However, it appears to differ from both species in the more spatulate anal point and in the presence of spines on the superior volsella. However, Heyn (1992: 133) mentions that both D. abruptus and D. obreptus , as in this species, lack the wide median notch on the antepronotum and probably should not be included in Demeijerea . The anal point and hypopygium is quite similar to the specimens mentioned by Gillespie (1974: 143 fig. 50) under D. brachialis as possibly being a new species and may be identical.

Figures

FIGURE 1. Demeijerea spp. A – C. Demeijerea spinulata sp. n. A – thorax; B – frontal tubercles; C – hypopygium. D – Demeijerea brachialis (Coquillett), female, lobes of gonapophysis, apodeme lobe (ApL), ventrolateral lobe (VlL) and dorsomesal lobe (DmL).