Review of genus Pseudorthocladius Goetghebuer, 1943 (Diptera, Chironomidae) from China

Abstract The genus Pseudorthocladius Goetghebuer, 1943 from China, including 12 species, is reviewed. Five new species, P. (P.) binarius sp. n., P. (P.) cylindratus sp. n., P. (P.) digitus sp. n., P. (P.) ovatus sp. n. and P. (P.) paucus sp. n. are described and illustrated as adult males. P. (P.) cristagus Stur & Sæther, 2004, P. (P.) jintutridecima (Sasa, 1996), P. (P.) macrovirgatus Sæther & Sublette, 1983, P. (P.) morsei Sæther & Sublette, 1983, P. (P.) uniserratus Sæther & Sublette, 1983, P. (L.) wingoi Sæther & Sublette, 1983 are newly recorded in Oriental Region. A key to the males of Pseudorthocladius in China is presented.

Etymology. The specific name is from Latin, binarius, meaning "of two", referring to the inferior volsella has two sub-lobes.
Distribution. The new species is collected in a subtropical mountain area in Fujian Province (Oriental China).
Distribution. The species is widely distributed in Holarctic region. Coloration. Head, abdomen, legs light brown; thorax with light brown ground with brownish black postnotum and preepisternum.
Female, pupa and larva unknown. Etymology. The specific name is from Latin, cylindratus, meaning "in the form of a cylinder", referring to the cylindrical anal point, which is unique in the genus.
Remarks. The new species resembles P. (P.) amplicaudus Saether & Sublette, 1983 in the structure of hypopygium, but the new species can be separated from latter on the basis of main characters in Table 4.
Distribution. The new species is known from Hunan, Hainan Province in Oriental China.
Coloration. Head, abdomen, legs brown; thorax with yellow ground with brown postnotum and preepisternum.
Remarks. P. (P.) digitus sp.n. is close to P. (P.) yakuxeyeus (Sasa & Suzuki, 2000) in the antenna ratio (0.71-0.74) and finger-liked inferior volsella. But it can be separated from the latter by having rounded anal point reaching beyond the caudal margin of tergite IX, reduced wing anal lobe and bare squama.
Distribution. The new species is known from Fujian Province in Oriental China. (Sasa, 1996) , 25.v.1996, Xinhua Wang, light trap;6 ♂♂, Yulong Naxi Autonomous County, Tiger Leaping Gorge, 27°11'24"N, 100°07'12"E, 26.v.1996, Xinhua Wang, light trap. Guangdong: 1 ♂, Fengkai County, 23°24'N, 111°30'E, 20.iv.1988 Remarks. Sasa (1996) described this species based on the material from Japan, and put it in the genus Eukiefferiella. Saether, Ashe and Murray (2000) transferred this species to the genus ? Psectrocladius. Yamamoto (2004) transferred it into the genus Pseudorthocladius. The Chinese specimens agree with the original description of Sasa (1996)  Remarks. The Chinese specimen mainly agrees with the original description by Saether and Sublette (1983). Some measured differences between the Chinese table 6. Differences between the specimens of China and description of Saether and Sublette (1983). specimen and the specimen described by Saether and Sublette (1983) are shown in Table 6 Remarks. Saether and Sublette (1983) described P. (P.) morsei based on the material from U.S.A. Its gonostylus has a basal inner lobe, sharply bend distad of the middle and narrow in apical posterior, which is unique among Pseudorthocladius. The Chinese specimen agrees with the description except some minor differences shown in Table 7.
Hypopygium (Figures 21-23). Laterosternite IX with 6-7, 6 setae. Tergite IX with round anal point, bearing 9-10, 9 long and strong setae.  Remarks. The new species is close to P. (P.) matusecundus Sasa & Kawai, 1987 in the structure of hypopygium, but can be separated from the latter on the basis of characters in Table 9.
Distribution. The new species is known from Zhejiang Province in Oriental China. Coloration. Head, abdomen, legs light brown; thorax with light brown ground with brownish black postnotum and preepisternum.