New species and records of Parametriocnemus Goetghebuer from China (Diptera, Chironomidae)

Abstract The Chinese species of Parametriocnemus Goetghebuer are reviewed. Two species, Parametriocnemus fortis sp. n. and Parametriocnemus vittatus sp. n. are described and illustrated as males, and Parametriocnemus ornaticornis (Kieffer), Parametriocnemus scotti (Freeman) and Parametriocnemus brundini Sinharay & Chaudhuri are recorded from China for the first time. A key to the males of the seven Chinese Parametriocnemus speciesis given.


Introduction
The genus Parametriocnemus was described as a subgenus of Metriocnemus van der Wulp by Goetgebuer (1933), based on M. stylatus Kieffer, 1924. It was raised to genus by Brundin (1956). The genus presently include 34 species worldwide. Seven species are recorded from the Oriental Region, 19 from the Palaearctic Region, 6 from the Nearctic Region, 1 from the Neotropical Region, 3 from the Afrotropical Region and 2 from the Australasian Region (Ashe and O'Connor 2012). Wang (2000) listed two species of Parametriocnemus from China, P. stylatus and P. lundbecki, based on males, while a record of P. lundbeckii was treated as dubious. Based on recently collected material from China, two new species are described and three additional species are recorded. A key to the males of the Chinese Parametriocnemus is presented.

Materials and methods
The morphological nomenclature follows Saether (1980). The material examined was mounted on slides in Canada balsam, following the procedure outlined by Saether (1969). Measurements are given as ranges.
The types and other material is housed in the College of Life Sciences, Nankai University, China (BDN).
Distribution. In China the species is known from the Fujian Province in the Oriental region only. Coloration. Head and wing light brown. Legs yellow. Thorax and abdomen blackish brown.
Remarks. The species is similar to P. stylatus (Kieffer) in the structure of the hypopgium, but can be distinguished by having much stronger anal point.
Distribution. The specimen was collected in Tibet in Palaearctic China. ( Remarks. The species differs from other members of the genus by having a triangular, broad inferior volsella with bluntly rounded corner. The species is very similar to P. stylatus (Kieffer), but differs in the shape of the inferior volsella, and the preapical projection of the gonostylus is much smaller and pointed than that in P. lundbeckii (Brundin 1956). According to Saether (1969), the immature stages seem to be inseparable, and as P. stylatus is known to be very variable (see Thienemann 1937) it might be a synonym of P. lunbdbeckii.

Parametriocnemus lundbeckii
Distribution. The species has been recorded from the Oriental, Neotropical and Nearctic Regions, and occurs in both of Oriental and Palaearctic China. Remarks. The species can be separated from other members of the genus by having a comparatively low AR (0.31-0.46), macrotrichiae forming streaks in the apical half of the wing, squama with 4-5 setae, and anal point with bare apex and 3-4 setae on each side. The species was described from Australia by Kieffer (1917) as a member of Metriocnemus van der Wulp, and was transferred to Parametriocnemus Goetghebuer by Freeman (1961). The specimens from China are in accordance with the original description, but have a lower LR and AR than specimens from India. The differences between specimens from China and India are listed in Table 3.
Distribution. The species has been recorded from Australia (Kieffer 1917) and India (Hazra et al. 2002). It occurs in both Oriental and Palaearctic China.

Parametriocnemus scotti (Freeman)
http://species-id.net/wiki/Parametriocnemus_scotti Metriocnemus scotti Freeman, 1953: 129. Parametriocnemus scotti (Freeman); Lehmann (1979: 42 Remarks. The species can be separated from other members of the genus by having a short anal point with bare, rounded apex; triangular inferior volsella, and clavate antenna with numerous curved bristles apically. The species is similar to P. brundini Sinharay et Chaudhuri in the structure of the hypopgium; it has a short anal point with bare apex, while that in P. brundini is longer. The species was redescribed and figured by Lehmann (1979, figs 124-125). However, no data for the legs was given; lengths (in µm) and proportions of the legs of the Chinese specimens are therefore given in Table 4.
Distrubution. The species has been recorded from Ethiopia (Abyssinia), Kenya, Uganda and Zimbabwe (Rhodesia) in the Afrotropical Region (Lehmann 1979), and it occurs in both Oriental and Palaearctic China. (   Remarks. The male differs from other members of the genus by having AR 0.79-1.09, wing membrane with numerous setae, a rather slender gonostylus without projection, robust anal point, and gonocoxite with a broad, subrectangular inferior volsella.

Parametriocnemus stylatus
According to Wang (2000), five females of this species were collected in the Yunnan Province. After re-examing the specimens, we found that all five specimens apparently are intersexes. One of these intersexes has a 10 segmented antenna, two have a 6 and two a 5 segmented antenna. They are morphologically similar to males, but differ from all species of Parametricnemus in structure of the male hypopygium and the female-like antenna, reduced number of setae on the antennal flagellum, and low antennal ratio (Figs 4-6). None of the males from the other localities appear to be intersexes.
Distribution. The species has been recorded from the Palaearctic and Nearctic Regions and occurs in both Oriental and Palaearctic China.
Coloration. Head, legs and antenna brown. Thorax light brown. Abdomen yellowish, tergites II-III with brown vita, 2/3 the width of the tergite, tergites IV-V with three brown patches on each tergite, and tergites VI -VII all brown (Fig. 7).
Remaks. The new species is similar to P. stylatus in the structure of the hypopyium, while the body color is close to P. scotti. However, both P. stylatus and P. scotti lack brown vita on tergites II-VII.
Distribution. The species was collected in Sichuan Province in Oriental China.