Thienemanniella lineola Freeman

Fu, Yue, Hestenes, Tor Christian & Saether, Ole, 2010, Review of Afrotropical Thienemanniella Kieffer (Diptera: Chironomidae: Orthocladiinae), Zootaxa 2338, pp. 1-22 : 11-15

Thienemanniella lineola Freeman

( Figs 4 A–G; Figs 5 A–D)

Thienemanniella lineola Freeman, 1953: 212 ; Freeman 1956: 367; Harrison 1992 [Key].

Material examined. SOUTH AFRICA: Cape Province: Wellington, Berg River, Station 3, 1 3, 13.v.1952, K.M.F. Scott ( BMNH). French Hoek, 2Ƥ, 22.x.1952, paratypes, K.M.F. Scott ( BMNH); Kirsten Bosch, 1 3, 29.iv.1952, paratype, K. M. F. Scott ( BMNH). Natal: Bushman`s River, Giant´s Castle Camp., 1 3, 14 – 30.ix.1953, A. D. Harrison ( BMNH).

Diagnostic characters. The adult male can be separated from the other members of the genus by the following combination of characters. It has 10 flagellomeres and only one anal vein on the wing. Superior volsella are fused and the inferior volsella shaped as a fleshy rounded lobe on the proximal half of the gonocoxite. Gonostylus is slender. Thorax has pale vittae. The first abdominal tergite has 2 setae in a patch mediolaterally to each side. The female is separated from the other members of the genus by having 3 strong setae on tergite IX, large seminal capsules, and 3 sensilla chaetica on ta2 of midleg.

Adult male (n = 4, except when otherwise stated)

Total length 1.18–1.30 (2) mm. Wing length 0.84–0.94 (3) mm. Total length/wing length 1.35–1.39 (2). Wing length/ length of profemur 3.62–3.77 (3). Wing width/wing length 0.37–0.39. Head yellow to orange; thorax light brown to hyaline with scutum, preepisternum, scutellum, postnotum and median anepisternum II dark brown, abdomen light brown, tergites VI and VIII with a paler area medially.

Head ( Figs 4 A–C). Eyes hairy, eye setae distinctly longer than height of ommatids, about 5 µm long; height of eye/height of head 0.65–0.68 (2). Antenna ( Fig. 4 B) with 10 flagellomeres; ultimate flagellomere club-shaped with notched or rounded apex, with 6–7 basal setae and about 25 sensilla chaetica. AR 0.20–0.31 (3). Cibarial pump as in Fig. 4 C, not incurved; tentorium 113–129 (3) µm long, stipes 68–79 (3) µm long. Palpomere lengths (in µm): 13–18 (3), 11–15 (3), 25–26 (3), 44 (1), 113 (1). Palpomere 5/ 3 ratio: 4.4 (1). Palpomere 3 elliptical, with 1 apical sensillum clavatum. Clypeus with 8–11 (3) setae. Outer verticals 0, coronals 4.

Thorax. Anapleural suture 117–132 µm long, s/a 0.60–0.66. Antepronotals absent; dorsocentrals 8–11, uniserial; prealars 2–4; scutellars 2.

Wing ( Fig. 4 D). VR 1.79–1.87. One anal vein present; An1/wing length 0.38–0.43; PCu/wing length 0.55– 0.62; C/wing length 0.32–0.37; Cu/wing length 0.43–0.47. C with 11–13 uniserial setae, wing setation otherwise as for T. trivittata .

Legs. Fore trochanter with keel. Spur of fore tibia 18–25 µm long; mid tibia with 3 small subequal spurs 10–16 µm long; apex of hind tibia ( Fig. 4 E) with serrated spur 25–29 µm long, smaller, strong spur 10–16 µm long and slight curved stiff seta about 15–20 µm long. Apex width (in µm): fore tibia 20–25, mid tibia 23–25, and hind tibia (a) 27–33. Width of hind tibia 1/3 from apex (d) 16–23 µm, elongation (b)15–19 µm long, maximum thickening (c1) at 27–34 µm from apex, total length of thickening (c2) 34–58 µm; a/d 1.44–1.69, b/ d 0.83–0.94, c1/1.26–2.00, c2/d 1.48–3.41. Hind tibial comb of 11 setae. Sensilla chaetica apparently absent. Ta1 of p2 with ventral row of 7–8 strong setae. Ta1 of p3 with two ventral rows of 6–8 strong setae, ta2 and ta3 with 1 strong apical seta ventrally, ta3 with 1 strong seta ventrally at 0.5 of length. Ta4 of all legs cordiform. Lengths (in µm) and proportions of legs as in Table 6.

Abdomen. Tergite I with 2+2 lateral setae. Tergites II–VIII 3–8, 5–6, 2–4, 3, 3,

1–3, 0–1. Sternites II with 1–2 setae, sternites III–VII with 1 median seta.

Hypopygium ( Fig. 4 F). Sternite VIII bare; tergite IX with about 15–20 small setae about 10 µm long; laterosternites IX with 2–3 setae about 18 µm long. Thin glandular setae, 10–15 µm long on inferior volsella and inner margin of gonocoxite. Superior volsella narrow, fused anteriorly. Inferior volsella rounded fleshy lobes on proximal half of gonocoxite, in contact with superior volsella. Phallapodeme 32–36 µm long, slightly curved. Transverse sternapodeme 27–34 µm long, lateral sternapodeme 29–38 µm long. Gonostylus slender, with strong megaseta 9–10 µm long. HR 2.29–2.81; HV 3.05–3.81 (2).

Adult female (n = 1–2)

Total length 1.08 mm. Wing length 0.77–0.88 mm. Total length/wing length 1.23. Wing length/profemur length 4.23–5.39. Wing width/wing length 0.36–0.37. Head yellow to light brown, thorax as for male, abdomen pale.

Head ( Fig. 5 A). Eyes hairy, hairs as for male. Height of eye/height of head 0.42–0.45. Flagellomere lengths (in µm): 25–36, 23–27, 27–30, 28–34, 49–51. AR 0.40–0.49. Ultimate flagellomere with about 15–20 sensilla chaetica in apical two-thirds. Tentorium broad ventrally with median extension, tentorium 79–83 µm long, stipes 68–83 µm long. Palpomere lengths (in µm): 11, 13–15, 22, 33–36, 77–84. Palpomere 5/ 3 ratio: 2.40–2.54; palpomere 3 round, 1 sensillum clavatum on inner part of apex. Clypeus with 7–8 setae. Outer verticals absent, coronals 4.

Thorax ( Fig. 5 B). Anapleural suture 80 µm long. Ratio s/a 0.61–0.65. Dorsocentrals 9, uniserial; prealars 2; scutellar 1, dorsally.

Wing ( Fig. 4 G). VR 1.63–1.77. One anal vein present, An1/wing length 0.48–0.49; PCu/wing length 0.57– 0.60; C 389–514, 472 µm long; C/wing length 0.56; Cu 380–394 µm long; Cu/wing length 0.46–0.51. Brachiolum with 1 seta. Costal margin with 12–16 biserial setae on apical 1/2 and 7–8 uniserial setae on basal 1/2, totally 19–24 setae.

Legs. Fore trochanter with dorsal keel. Fore tibia with serrated spur 20–23µm, mid tibia with spurs 14 and 9–10, hind tibia with serrated spurs 25–27 µm and 10 (1) µm long. Apex width (in µm): of fore tibia 20, of mid tibia 20–23, of hind tibia (a) 29–33. Width of hind tibia 1/3 from apex (d) 20–25 µm, elongation (b) 11–15 µm long, length of maximum thickening (c1) 25–27 µm, total length of thickening (c2) 36–52 µm; a/d 1.27– 1.48, b/d 0.57–0.59, c1/d1.00–1.36, c2/d 1.82–2.09. Hind tibial comb with 12 setae. Ta2 of frontleg1 with 1 ventral strong setae subapically, ta4 with 2 mesally curved seta apically. Ta1 of hind leg with two ventral rows of 7 strong setae, ta3 with 1 strong ventral setae at 0.47 of length, ta2 with 2 strong seta and 1 strong apical seta, all ventrally. Mid ta2 with 3 sensilla chaetica at 0.52–0.56 to 0.78–0.81 of length. Lengths (in µm) and proportions of legs as in Table 7.

Abdomen. Tergite I with 1 setae to each side. Number of setae on tergites II–VII not countable.

Genitalia ( Figs 5 C–D). Tergite IX with 3 large setae caudally, gonocoxites IX with 2 smaller setae. Segment X with numerous small spine-like microtrichia, forming caudally extending rectangular socket for cerci, with a small insertion medially. Gonapophysis VIII not divided at surface, apparently with subcuticular traces of such division. Elliptical postgenital plate hinged to anterior ventral margin of segment X, caudally to gonapophysis VIII, carrying fine spine like microtrichia. Internally below seminal eminence paired labia, forming the floor of vaginal cavity. Large bursa with faint sclerotized walls dorsal to gonapophysis VIII. Seminal capsules large, 68 µm long, 36 µm wide; oblong oval-shaped; somewhat pointed tip in distal end; prominent neck 10 µm long; seminal ducts fused 12 µm anterior to eminence. Coxosternapodeme thick, curved in whole length, no anterior lamella. Cercus length 32 µm. Notum length 50 µm, ramus broadened anterior and posterior.

Distribution. The species is known from Cape Province, Transvaal and Natal in South Africa, and from the Democratic Republic of the Congo. It is also known from the Ethiopian Highlands ( Harrison 1992).

Remarks. Two of the males and females in Freeman’s material were misidentified and belong to T. fuga . The arrangement of the inferior volsella in this species is as a basal swelling of the inner gonocoxite, which is the most common type of inferior volsella seen in Thienemanniella . The labia of the female is very like the labia of Psectrocladius (Allopsectrocladius) flavus Johannsen as showed in Saether (1977 fig 41 C), although differing in many other details.

Figures

FIGURE 4. Thienemanniella lineola Freeman. Adult male. A. Head. B. Antenna. C. Cibarial pump. D. Wing. E. Hind tibia apex. F. Hypopygium. Adult female. G. Wing.

FIGURE 5. Thienemanniella lineola Freeman. Adult female. A. Head. B. Thorax. C. Genitalia, dorsal view. D. Genitalia, ventral view.