Bryophaenocladius flexidens ( Brundin, 1947 )

Du, Jing, Wang, Xin-Hua & Saether, Ole, 2011, Redescriptions of species of Bryophaenocladius Thienemann, 1934 (Diptera: Chironomidae) described by Brundin (1947), Zootaxa 2743, pp. 40-48 : 42-44

Bryophaenocladius flexidens ( Brundin, 1947)

( Figures 3–5 )

Chaetocladius flexidens Brundin, 1947: 24 , figure 48.

Bryophaenocladius flexidens (Brundin) : Ashe & Cranston 1990: 161.

Type material. Lectotype, male, here designated, SWEDEN: Jämtland, Gäddede, at the rapids, 7.x. 1945, A. Määr. Paralectotypes, SWEDEN: 4 males, same data as lectotype; Jämtland, Lake Jormsjön, at the mouth of the Blåsjö River, 4 males, 8.x. 1945, A. Määr.

Diagnostic characters. The male imago is characterized by a large, pointed triangular anal point; an inward curved inferior volsella, and a curved gonostylus.

Male imago (n = 9). Total length 2.90–3.66, 3.25 mm. Wing length 1.96–2.56, 2.22 mm. Total length / wing length 1.35–1.59, 1.47. Wing length / length of profemur 2.24–2.65, 2.43. Coloration black brown.

Head. AR 1.48–1.83, 1.66. Ultimate flagellomere with apical seta. Temporal setae 6–11, 8, including 2–5, 3 inner verticals; 2–3, 2 outer verticals; and 2–4, 3 postorbitals. Clypeus with 10–20, 13 setae. Tentorium 161–183, 171 Μm long. Stipes 132–165, 149 Μm long. Palpomere lengths (in Μm): 31–42, 36; 40–62, 55; 128–163, 142; 97– 136, 119; 121–170, 146. Third segment without finger-like apical extension.

Thorax. Dorsocentrals 10–19, 13; antepronotals 4–6, 4; acrostichals not observed; prealars 4–8, 6; scutellars 6– 12, 8.

Wing ( Fig. 3 ). Anal lobe not projecting. Punctation visible at 100x magnification. VR 1.12–1.19, 1.15. R2+3 ends at 3/5 distance between R1 and R4+5. Costal extension 76–112, 100 Μm long. Brachiolum with 1 seta; R with 7– 17, 12 setae; R1 with 0–7, 2 setae; remaining veins bare. Cu1 slightly curved. Squama with 8–18, 12 setae.

Legs. Spur of front tibia 68–90, 77 Μm long, spurs of middle tibia 51–70, 62 Μm and 22–33, 29 Μm long, of hind tibia 75–86, 79 Μm and 22–33, 28 Μm long. Hind tibial comb with 18–20, 19 setae. All tibial spurs with lateral denticles. 4th tarsomere obviously longer than 5th tarsomere in all legs. Lengths and proportions of legs as in Table 2 .

Hypopygium ( Fig. 4–5 ). Anal point slender, 50–73, 63 Μm long, 25–36, 28 Μm wide. Tergite IX with 14–20, 16 setae. Laterosternite IX with 8–18, 10 setae. Phallapodeme 112–150, 124 Μm long; transverse sternapodeme 110– 147, 121 Μm long. Virga consisting of 8–12, 9 spines, 59–68, 64 Μm long. Gonocoxite 220–260, 233 Μm long. Inferior volsella hooked, with several short setae. Gonostylus 92–120, 104 Μm long; crista dorsalis reduced, megaseta 11–22, 15 Μm long. HR 2.02–2.50, 2.26, HV 2.82–3.47, 3.15.

Remarks. There are a few minor differences with Brundin’s original description, such that R2+3 ends at 3/5 the distance between R1 and R4+5, while R2+3 ends in anterior third between R1 and R4+ 5 in Brundin (1947: 25).

Distribution. The species is known from Britain, Denmark, Finland, France, Germany, Romania, Spain and Sweden ( Saether & Spies 2004).

Figures

FIGURES 3 – 5. Bryophaenocladius flexidens Brundin, 1947. 3. Wing. 4. Hypopygium, dorsal view. 5. Hypopygium, ventral view.

Tables

TABLE 2. Length (in µm) and proportions of legs of Bryophaenocladius flexidens Brundin, male (n = 9).

	fe	ti	ta1	ta2	ta3	ta4	ta5	LR	BV	SV
p1	864–989, 904	1046–1248, 1106	614–902, 690	326–480, 379	239–335, 268	143–210, 169	96–124, 100	0.59–0.72, 0.66	2.73–3.14, 2.95	2.48–3.11, 2.91
p2	912–1056, 959	943–1104, 1002	394–576, 470	191–278, 238	134–205, 180	96–153, 119	86–123, 102	0.41–0.52, 0.47	3.52–4.44, 3.81	3.75–4.95, 4.18
p3	941–1162, 1010	1133–1363, 1218	595–697, 657	287–422, 338	220–316, 256	124–191, 150	96–123, 114	0.51–0.59, 0.54	3.17–3.63, 3.36	3.27–3.60, 3.39