Paracladius ovatus, Fu, Yue, Wang, Xinhua & Andersen, Trond, 2010

Fu, Yue, Wang, Xinhua & Andersen, Trond, 2010, Chinese Paracladius Hirvenoja, with the description of P. ovatus sp. n. (Chironomidae: Orthocladiinae), Zootaxa 2453, pp. 62-68 : 65-67

Paracladius ovatus sp. n.

( Figs 5–10 )

Type material. Holotype male, CHINA: Yunnan Province, Zhongdian County, 27°49'N, 99°42'E, 3.284 m a.s.l., 14.vii.2001, light trap, Xinhua Wang (BDN No. 20112).

Diagnostic characters. The species groups with Paracladius akansextus Sasa et Kamimura in having an anal point with lateral setae and inferior volsella with rounded apex. It can be separated from P. akansextus by having a comparatively long, narrow anal point, a rounded inferior volsella and a short costal extension.

Etymology. From Latin, ovatus , egg-shaped, referring to the shape of inferior volsella.

Male (n = 1). Total length 3.55 mm. Wing length 2.35 mm. Total length / wing length 1.50. Wing length / length of profemur 2.70.

Coloration. Head dark brown, palpomeres and antennae yellowish brown. Thorax, legs, and abdomen brown.

Head. AR 1.31, ultimate flagellomere 630 µm long. Temporal setae 11, including 4 inner verticals and 7 outer verticals. Clypeus with 8 setae. Tentorium and stipes as in Figure 5 ; cibarial pump as in Figure 6 . Tentorium 165 µm long, 48 µm wide. Stipes 165 µm long, 48 µm wide. Palpomeres lengths (in µm): 40, 70, 120, 138, 205. Palpomere 5/3: 1.7.

Wing ( Fig. 8 ). VR 1.1. R with 7 setae, brachiolum with 1 seta. Squama with fringe of 18 setae. Costal extension 12 µm long. Cu 1000 µm long. Cu / wing length 0.43. Wing width / wing length 0.30.

Thorax ( Fig. 7 ). Antepronotals and acrostichals difficult to discern; antepronotum apparently with about 5 lateral setae, acrostichals at least 5, dorsocentrals 12, prealars 8. Scutellum apparently with about 8 setae.

Legs. Spur of fore tibia 45 µm long; spurs of mid tibia 30 µm and 25 µm long; of hind tibia 68 µm and 10 µm long. Hind tibial comb with 12 setae. Width at apex of fore tibia 45 µm; of mid tibia 50 µm; of hind tibia 55 µm. Sensilla chaetica 13 on ta1 of hind leg. Lengths and proportions of legs as in Table 2.

Hypopygium ( Figs 9–10 ). Anal point 50 µm long, 18 µm wide at base, 5 µm wide at apex, with 5 lateral setae. Tergite IX with 8 additional setae; laterosternite IX with 7 setae. Phallapodeme 83 µm long; transverse sternapodeme 138 µm long. Inferior volsella rounded, with 8 strong marginal setae in double row. Gonocoxite 238 µm long. Gonostylus 95 µm long, with rounded crista dorsalis; megaseta 13 µm long. HR 2.5; HV 3.7.

Remarks. Paracladius ovatus sp. n. is quite similar to P. ankasextus in most features. However, the anal point in Paracladius ovatus sp. n. is distinctly longer (50 µm) and more strongly tapering compared to the anal point in P. ankasextus , which is about 32 µm long. Although the positioning of the specimen on the slide to some degree might influence the shape of the inferior volsella, the inferior volsella in P. ovatus sp. n. also appears to be distinctly more broadly rounded than in P. ankasextus . Paracladius ovatus sp. n. has 13 sensilla chaetica on ta1 of the hind leg, while P. ankasextus has 6–8. As P. ovatus sp. n. is slightly larger (wing length 2.35 mm) than P. ankasextus (wing length about 2.00 mm), this difference might prove to be within the natural variation when a larger material is examined. However, in P. ankasextus the costal extension is rather long (30–50, 42 µm) while in P. ovatus sp. n. it is much shorter (12 µm), a difference which should clearly separate the two species. Although based on a single specimen, we therefore find that P. ovatus sp. n. warrants the status as a separate species.

Distribution. The species was collected in a subtropical mountain area in Oriental China.

Figures

FIGURES 5 – 10. Paracladius ovatus sp. n., male. 5 – tentorium and stipes; 6 – cibarial pump; 7 – thorax; 8 – wing; 9 – hypopygium, dorsal view; 10 – hypopygium with anal point and tergite IX removed, dorsal aspect to the left, ventral aspect to the right.