Polypedilum (Uresipedilum) pedatum Townes

Saether, Ole A., Andersen, Trond, Pinho, Luiz C. & Mendes, Humberto F., 2010, The problems with Polypedilum Kieffer (Diptera: Chironomidae), with the description of Probolum subgen. n., Zootaxa 2497, pp. 1-36 : 24-28

Polypedilum (Uresipedilum) pedatum Townes

( Figs 32–43 )

Polypedilum pedatum pedatum Townes, 1945: 55 .

Material examined. USA: New York, Tompkins Co., McLean Bogs Reserve, holotype male, hypopygium on separate slide in Canada balsam (Cornell University, Dept. of Entomology, Type No. 2671). Paratypes: as holotype, 3 males, 2 females (Cornell University, Dept. of Entomology, Types No. 2671.6, 2671.7, 2671.8, 2671.9, 2671.10).

Diagnostic characters. The male imagines apparently differ from P. excelsius by not having R4+5 reaching apex of wing, projection of superior volsella at most as long as base, third palpomere with 4–7 lanceolate sensilla clavata, squama with 6–10 setae and M often with apical seta.

Male (n = 3–4, except when otherwise stated). Total length 3.15–4.01, 3.57 mm. Wing length 1.79–2.21 mm. Total length / wing length 1.80–1.86. Wing length / length of profemur 2.20–2.48.

Coloration. Thorax brown with darker vittae, postnotum, preepisternum and much of anepisternum; scutellum pale. Legs beyond coxae pale brown. Abdomen brown, gonocoxite and gonostylus pale.

Head. AR 1.07–1.16, 1.11. Ultimate flagellomere 548–614, 578 μm long. Temporal setae 15–20 including 5–8 inner verticals; 6 outer verticals and 4–6, 5 postorbitals. Clypeus with 13–19 setae. Tentorium 148–165, 151 μm long; 38–45, 42 μm wide at sieve pore. Stipes 135–161 μm long, 38–49 μm wide. Palpomere lengths (in μm): 41–45, 44; 53–60, 56; 135–180, 161; 131–169, 154; 191–278, 231. Third palpomere with 4–7 lanceolate sensilla clavata, longest 26 μm long.

Thorax. Acrostichals 16–18, 17; dorsocentrals 16–18, 17, including 1 scutal fossal setae in one specimen; prealars 6–8. Scutellum with 15–17, 16 biserial setae.

Wing ( Fig. 32 ). VR 1.07–1.25. R2+3 well separated from R1. Apical part of R4+5 curved near apex, ending nearer apex of M1+2 than to wing tip. Brachiolum with 2 setae, R with 19–25, R1 with 14–22, R4+5 with 26–33, M with 0–1 setae. Squama with 6–10 setae.

Legs. Scale on fore tibia 30–38, 36 μm long, rounded, without spur. Spur of mid tibia 49–53 μm long including comb, unspurred comb 26–30 μm long. Spur on hind tibia 56 μm long including comb, unspurred comb 30 μm long. Width at apex of fore tibia 41–56, 49 μm; of mid tibia 49–56 μm; of hind tibia 64 μm. Length and proportions of legs as in Table 4.

Hypopygium ( Figs 33–34 ). Tergite IX with 6–11, 9 strong median setae and altogether 14–20, 17 setae to each side of base of anal point. Anal point 53–68, 60 μm long, parallel-sided. Transverse sternapodeme 34– 49, 38 μm long; phallapodeme 101–120, 109 μm long. Gonocoxite 169–210, 188 μm long. Gonostylus 128– 158, 148 μm long, with 1 apical seta and 6–8 long setae along inner margin. Base of superior volsella ( Fig. 35 ) sparsely covered with microtrichia, 34–41, 37 μm long; with 53–56, 55 μm long apicolateral seta and 2 basal inner setae; apical projection 30–39, 34 μm long, upturned at apex. Inferior volsella 113–131, 122 μm long, nearly parallel-sided with slightly divided apex, with 14–17, 15 setae. HR 1.17–1.33, 1.28. HV 1.99–2.69, 2.43.

Female (n = 1–2). Total length 3.52–3.64 mm. Wing length 2.21–2.34 mm. Total length / wing length 1.55–1.83. Wing length / length of profemur 2.13.

Coloration. Thorax brown with darker vittae, postnotum, preepisternum and much of anepisternum; scutellum pale. Legs beyond coxae pale brown. Abdomen brown, gonocoxite and gonostylus pale.

fe ti ta1 ta2 ta3 ta4 p1 813–1011, 917 652–813, 754 1068 690 520 345 p2 917–1115, 1016 869–964, 910 473–520 274–312 208–227 118–137 p3 1058–1106 992–1058 – – – –

ta5 LR BV SV BR p1 142 1.35 1.68 1.67 3.1 p2 66–85 0.53–0.54 3.27–3.42 4.00–4.06 4.5–5.5 p3 – – – – –

Head. AR = 0.38. Flagellomere lengths (in μm): 143, 105, 94, 71, 150. Longest sensilla chaeticae on ultimate flagellomere 71 μm long. Temporal setae 18–20 including 6–9 inner verticals, 6 outer verticals and 5–6 postorbitals. Clypeus with 18–20 setae. Tentorium 154–184 μm long, 30 μm wide at sieve pore. Stipes 154 μm long, 45 μm wide. Palpomere lengths (in μm): 45–56, 60–64, 176–184, 158–173, 278–308. Third palpomere with 6–7 lanceolate sensilla clavata, longest 26 μm long.

Thorax ( Fig. 37 ). Acrostichals 20–22; dorsocentrals 25–30, including 5–9 scutal fossal setae; prealars 7. Scutellum with 18–20 biserial setae.

Wing ( Fig. 38 ). VR 1.16–1.19. R2+3 well separated from R1. Brachiolum with 2 setae, R with 28–31, R1 with 22–28, R4+5 with 40–56, M with 5–7 setae. Squama with 8–9 setae.

Legs. Scale on fore tibia ( Fig. 36 ) 38 μm long, rounded, without spur. Spur of mid tibia 49–53 μm long including comb, unspurred comb 23–26 μm long. Spur on hind tibia 49–56 μm long including comb, unspurred comb 23–26 μm long. Width at apex of fore tibia 64 μm, of mid- and hind tibia both 71 μm. Length and proportions of legs as in Table 5.

TABLE 5. Lengths (in μm) and proportions of legs of Polypedilum (Uresipedilum) pedatum Townes , female (n = 1–2). fe ti ta1 ta2 ta3 ta4 ta5 LR BV SV BR p1 1040 765 – – – – – – – – –

p2 1002–1106 964–983 501 293 217 151 85 0.51–0.52 3.47 3.92–4.17 4.0 p3 1238 1096–1125 737 – – – – – – – – Abdomen. Number of setae on tergites I–VIII as: 46–67, 47–77, 48–70, 35–56, 27–46, 30–46, 42–46, 29– 36. Number of setae on sternites I–VIII as: 0, 3–4, 10–26, 25–34, 22–33, 26–33, 32–33, 45–69.

Genitalia ( Fig. 39 ). Gonocoxapodeme completely straight to slightly curved, ending on base of dorsomesal lobe. Gonocoxite IX with 3–6 setae. Tergite IX ( Fig. 40 ) with 36–44 setae. Segment X with 4–6 setae to each side. Cercus 124 μm long. Seminal capsule ovoid, 90–101 μm long, 70 μm wide, with 15–19 μm long neck. Notum 139–150 μm long. Dorsomesal lobe ( Fig. 41 ) 98–105 μm long from base of vagina to apex, 53–56 μm wide near apex. Ventrolateral lobe ( Fig. 42 ) 30–38 μm long, 30–38 μm wide. Apodeme of apodeme lobe as in Figure 43 .

Figures

FIGURES 32 – 35. Polypedilum (Uresipedilum) pedatum Townes, 1945, male. 32 – wing. 33 – hypopygium, dorsal view. 34 – hypopygium with tergite IX and anal point removed, dorsal view left, ventral view right. 35 – superior volsella.

FIGURES 36 – 43. Polypedilum (Uresipedilum) pedatum Townes, 1945, female. 36 – spur of foretibia. 37 – thorax. 38 – wing. 39 – genitalia, ventral view. 40 – tergite IX. 41 – dorsomesal lobe. 42 – ventrolateral lobe. 43 – apodeme lobe.