Polypedilum (Pentapedilum) anale (Freeman)

Oyewo, Emmanuel Adeoye & Saether, Ole A., 2008, Revision of Polypedilum (Pentapedilum) Kieffer and Ainuyusurika Sasa et Shirasaki (Diptera: Chironomidae), Zootaxa 1953, pp. 1-145 : 35-39

Polypedilum (Pentapedilum) anale (Freeman)

( Figs 7–8)

Pentapedilum anale Freeman, 1954: 22 ; Freeman (1955b: 376); Freeman and Cranston (1980: 195).

Polypedilum (Pentapedilum) anale (Freeman) ; Freeman (1958: 303).

Material examined. SOUTH AFRICA: Cape Province, Palmiet River, Elgin, holotype male, 20.xi.1952, P. Brink ( BMNH); Cape Province, Berg River , 1 male paratype, 25.xi.1952, 1 female paratype, v.1952, K. M. F. Scott (B. M. 1953–79, BMNH); Transvaal, Olifantsviei near Johannesburg & Klipspuit near Witbank, 1 male, 2 females, viii.1954 & 04.v.1956, K. M. F. Scott (B. M. 1955–176 & 24, 23, BMNH); Natal, Merrivale district near Howick, 1 female, 13–31.x.1990, at light, B. R . Stuckenberg ( ZMBN) . ZIMBABWE: Salisbury , 1 male, iv.1956, E. T . M. Reid (B. M. 1956–288, BMNH) . UGANDA: Kampala, 1 male, 04.xi.1929, G. L. R . Hancock (B. M. 1948–66, BMNH) . GHANA: Eastern Region, Subri River near Kibi , 3 males, 04.ii.1993, light trap, NUFU project ( ZMBN).

Diagnostic characters. The male differs from other species with a very broad anal point ( convexum group) except P. (Pe.) kasumiense by having anal point with a V-shaped median furrow, sharply pointed projection of superior volsella, and cell m basal of RM with less than 25 setae. It differs from P. (Pe.) kasumiense by having less numerous macrotrichia on the wing with cell m basal of RM with 1–13 macrotrichia as opposed to 14–20 in P. (Pe.) kasumiense , 9–16 dorsocentrals as opposed to 23–26, and 17–25 setae on the clypeus as opposed to 29–30 in P. (Pe.) kasumiense .

The female has a simple, nearly straight, brush-like ventrolateral lobe, a caudally broad dorsomesal lobe, and segment X with not more than 4 setae.

Male (n = 6–8, unless otherwise stated)

Total length 2.12–3.60, 2.79 (4) mm. Wing length 1.28–2.04, 1.59 mm. Total length / wing length 1.65– 3.60, 2.79 (4). Wing length / length of profemur 2.07–2.70, 2.32. Postnotum, antepronotum, preepisternum and scutum almost completely brown. Abdomen pale brown with dark apices, femur, tibia and tarsi brown.

Head. AR 1.35–1.56, 1.36. Ultimate flagellomere 498–641, 546 µm long. Temporal setae 6–11 including 2–4, 3 inner verticals; 4–5, 4 outer verticals; and 1–3, 2 postorbitals. Clypeus with 17–25, 20 setae. Tentorium 82–131, 108 µm long; 5–7, 6 µm wide at posterior tentorial pit. Stipes 103–143, 123 µm long. Palpomere lengths (in µm): 26–38, 32; 29–45, 37; 82–119, 98 (7); 98–138, 115 (7); 128–168, 156 (4). Fifth palpomere / third palpomere 1.56–2.00, 1.72 (4). Third palpomere with 2–3 sensilla clavata.

Thorax. Acrostichals 10–18, 13; dorsocentrals 9–16, 13; prealars 3–6, 4. Scutellum with 4–11, 7 setae.

Wing ( Fig. 8A). Anal lobe moderately reduced. VR 1.17–1.26, 1.21. Brachiolum with 1–2, 1 seta; Sc with 6–29, 15 setae; R with 22–42, 32; R 1 with 13–32, 24; R 4+5 with 38–64, 51; M with 5–12, 8; RM with 0–3, 1; M 1+2 with 48–85, 58; M 3+4 with 24–46, 32; Cu with 17–55, 28; Cu 1 with 12–24, 18; PCu with 25–80, 50; An with 16–46, 29 setae. Cell r 4+5 and m 1+2 with more than 100; m 3+4 with about 60 to more than 100 macrotrichia; cell m basal of RM with 1–13, 6 macrotrichia; an plus cu with about 50 to more than 100 macrotrichia. Squama with 3–8, 5 setae.

Legs. Scale on foretibia ( Fig. 8B) including minute apical spur 28–48, 39 µm long. Spurs on midtibia 51– 67, 57 µm long, on hind tibia 63–65, 60 µm long. Comb on midtibia 8–26, 18 µm long; combs on hind tibia 18–21, 20 µm and 9–20, 17 (5) µm long. Width at apex of foretibia 33–50, 39 µm; of midtibia 26–48, 42 µm; of hind tibia 28–52, 28 µm. Lengths and proportions of legs as in Table 4.

wise stated).

Hypopygium ( Fig. 7). Tergite IX with 12–22, 15 median setae, laterosternite IX with 2–3, 2 setae. Anal point ( Fig. 7B) broad; 54–55, 52 µm long; 29–60, 39 µm wide at base; nearly parallel-sided medially, apex broad and rounded, 21–24 µm wide. Transverse sternapodeme 28–50, 37 µm long; phallapodeme 60–88, 74 µm long. Gonocoxite 117–157, 136 µm long. Superior volsella ( Fig. 7C) 20–48, 30 µm long; base very broad with microtrichia and 3–4 inner setae, with needle-like projection bearing 1 lateral seta. Inferior volsella 67– 102, 88 µm long; parallel-sided, with 1 prominent apical seta. Gonostylus 89–140, 113 µm long. HR 1.05– 1.38, 1.22 (4). HV 2.38–3.53, 2.70 (4).

Female (n = 4, unless otherwise stated)

Total length 2.01–2.13 (2) mm. Wing length 1.71–2.07, 1.86 mm. Total length / wing length 1.25–1.62 (2). Wing length / length of profemur 1.96–2.69, 2.37. Thorax almost completely brown, abdominal segments pale brown to brown with slightly darkened apices; femur, tibia and tarsi brown.

Head. AR 0.30–0.37 (3). Temporal setae 7–12; including 4–5, 4 inner verticals, 3–5, 4 outer verticals, and 1–2, 2 postorbitals. Clypeus with 19–24, 20 setae. Tentorium 100–144, 125 µm long; 4–6 (2) µm wide at posterior tentorial pit. Stipes 143–169, 152 µm long. Palpomere lengths (in µm): 30–38, 34; 36–40, 39; 105–126, 116; 119–135, 124; 200–252 (3). Fifth palpomere / third palpomere 1.83–2.00 (3). Third palpomere with 2–3 sensilla clavata.

Thorax. Acrostichals 10–14, 13; dorsocentrals 17–33, 23; prealars 5–6, 6. Scutellum with 5–11 (3) setae.

Wing. Anal lobe moderately reduced. VR 1.13–1.23. Brachiolum with 1–3, 2 setae; R with 42–49, 46; R 1 with 27–52, 37; R 4+5 with 57–87, 70; Sc with 17–36, 24; RM with 3–5, 4; M with 8–14, 13; M 1+2 with 68–83, 77; M 3+4 with 39–55, 47; Cu with 38–49, 44; Cu 1 with 18–34, 28; PCu with 52–81, 71 and An with 34–49, 41 setae. Cells r 4+5, m 1+2, m 3+4, cell m basal of RM; cu plus an with dense macrotrichia.

Legs. Foretibial scale 36–42, 40 µm long; apical spur 10–14 (3) µm long. Spurs on midtibia 43–56, 51 µm long; on hind tibia 56–64, 61 µm long. Comb on midtibia 19–36, 22 µm long; combs on hind tibia 23–39, 25 µm and 18–24, 21 µm long. Width at apex of foretibia 44–54, 49 µm; of midtibia 40–60, 50 µm; of hind tibia 54–67, 61 µm. Length and proportions of legs as in Table 5.

Genitalia ( Figs 8C–F). Gonocoxite IX with 2–5, 4 setae; tergite IX with 20–38, 29 setae; segment X with 2–4, 3 setae. Cercus 80–100, 91 µm long; 4–5 (3) µm wide at apex. Seminal capsule ovoid 50–88 (2) µm long; 29–49 (3) µm wide; neck sclerotized 7–13 (3) µm long. Notum 126–162, 147 µm long. Dorsomesal lobe ( Fig. 8D) 96–105, 98 µm long, 37–50, 44 µm wide; ventrolateral lobe ( Fig. 8E) brush-like and straight; apodeme lobe ( Fig. 8F) almost inverted U-shaped. Postgenital plate triangular.

Remarks. Three species, P. (Pe.) anale , P. (Pe.) convexum , and P. (Pe.) kasumiense are very similar and believed to be synonyms by Hashimoto (1983). However, there are differences that merit these species to be kept apart. The males all have a very broad anal point with a distinct median furrow. The median furrow of P. (Pe.) convexum , however, is nearly parallel-sided, while those of P. (Pe.) kasumiense and P. (Pe.) anale are virtually V-shaped. The wing membrane of P. (Pe.) kasumiense is completely covered with numerous macrotrichia, a distinguishing character from P. (Pe.) anale and P. (Pe.) convexum . The latter has sparse setation, with for instance a little more than 100 macrotrichia in cell m basal of RM. P. (Pe.) anale has fewer macrotrichia with wing cell m basal of RM with 1-13 macrotrichia; m 3+4 and cu+an each with less than 100 macrotrichia. P. (Pe.) kasumiense has more than 23–26 dorsocentrals while P. (Pe.) convexum has 15–17 and P. (Pe.) anale 9–16. The LR 1 of P. (Pe.) convexum is 2.25–2.29 (always higher than 2.00) while P. (Pe.) kasumiense has 1.82–1.92 (always lower than 2.00) and P. (Pe.) anale 1.58(?)–2.28.

The pupa of P. (Pe.) kasumiense is similar to that of P. (Pe.) convexum in having bare segments VII and VIII. However, it can be distinguished from P. (Pe.) convexum by having several rows of spinules posteriorly on segments II–VI as opposed to 2 spots in P. (Pe.) convexum . The larva of P. (Pe.) kasumiense can be distinguished by the mentum. The median teeth are larger than the second lateral tooth, with a minute first lateral and progressively decreasing third to sixth lateral teeth and a minute seventh tooth, whilst in P. (Pe.) convexum , the second lateral tooth is larger than the median teeth, a minute first lateral tooth and subequal third to sixth lateral teeth and a minute seventh tooth. The immatures of P. (Pe.) anale was not available for description.

Distribution. Known from Ghana, South Africa, Burkina Faso, Lesotho, Madagascar, Namibia, Uganda, Zimbabwe and Democratic Republic of Congo ( Freeman & Cranston 1980: 195).