Xenochironomus trisetosus (Kieffer, 1922)

Fusari, Lívia Maria, Roque, Fabio De Oliveira & Hamada, Neusa, 2013, Review of Xenochironomus Kieffer, 1921 (Diptera: Chironomidae) with description of six new species, Zootaxa 3646 (2), pp. 101-126 : 107

Xenochironomus trisetosus (Kieffer, 1922)

Cladopelma trisetosus Kieffer 1922: 54 .

Xenochironomus trisetosus (Kieffer, 1922) ; Freeman 1957: 381.

Original material: not located.

Material examined: SUDAN, Melut, 2 males, leg. Freeman (BMNH), pinned material, only genitalia mounted on slides. ETHIOPIA, Tana-See, Lichtfang, 26. i.1977, 1 male, leg.: Reichholf (ZSM).

Diagnosis. Xenochironomus trisetosus can be separated from other species in the genus by the following characteristics: male, superior volsella digitiform-shaped; inferior volsella very narrow with few microtrichia; two to three long curved setae on the apex; gonostylus extending medially to distally.

Description. Male (n = 1–3)

Color. Thorax with pronotal region dark brown. Abdomen brownish. Femur, tibia and tarsomere 1–5 brownish. Head. AR 2.5. Apical flagellomere 760 Μm long. Clypeus with 12 setae. Lengths of palpomere 1–5 (in µm): 42, 44, 164, 170, 248.

Thorax. Ac 14; Dc 10; Pa not observed; Scts 6.

Wing. VR 1.15. Brachiolum with 2 setae. R with 29 setae, R1 with 22, R4+5 with 24, remaining veins bare. Squama with 9 setae.

Legs. Length (µm) and proportions of leg segments as in Table 3 .

Abdomen. In poor state of conservation.

Hypopygium. ( Fig. 3 A–B) Laterosternite IX with 5 setae. Anal tergite with 21–24 setae divided into 2 areas. Anal point 50–118 Μm long; 50–115 Μm wide at the base. Phallapodeme 72–178 Μm long; transverse sternapodeme 34–100 Μm long. Superior volsella 30–121 Μm long, 28 Μm wide at the base and 10–28 Μm wide at the apex. Inferior volsella 114–243 Μm long, 21–37 Μm wide at the base and 10–18 Μm wide at the apex. Gonocoxite 184– 284 Μm long. Gonostylus 193–224 Μm long. HR 0.80–1.50.

Female and immatures: unknown.

Figures

FIGURE 3. Xenochironomus trisetosus (Kieffer, 1922), male. A—dorsal aspect of tergite IX including anal point, dorsal view gonocoxite and gonostylus left; B—hypopygium with anal point and tergite IX removed, dorsal view left, ventral view right.

Tables

TABLE 3. Length (in μm) and proportions of legs of Xenochironomus trisetosus, male (n = 1).

	fe	ti	ta1	ta2	ta3	ta4	ta5	LR	BV SV
P1	990	800	640	590	520	440	190	0.80	1.40 2.80
P2	890	880	490	270	210	130	80	0.56	3.28 3.61
P3	1080	1140	760	380	320	200	120	0.67	2.92 2.92