Pseudorthocladius (Pseudorthocladius) paucus, Ren, Jing, Lin, Xiaolong & Wang, Xinhua, 2014

Ren, Jing, Lin, Xiaolong & Wang, Xinhua, 2014, Review of genus Pseudorthocladius Goetghebuer, 1943 (Diptera, Chironomidae) from China, ZooKeys 387, pp. 51-72 : 61-62

Pseudorthocladius (Pseudorthocladius) paucus sp. n. Figures 24-30

Diagnosis.

The male imago can be distinguished from the known species of the genus by the following combination of characters: with few setae on squama, R4+5 and acrostichals; gonostylus expanded at the apex; anal point triangular baring about 7 stout setae; inferior volsella inserted along the gonocoxite, parallel–sided.

Description.

Adult male (n = 3). Total length 1.49-1.60 mm. Wing length 0.77-0.92 mm. Total length/wing length 1.74-1.75. Wing length/length of profemur 2.56-2.58.

Coloration. Head, abdomen, legs light brown; thorax with light brown ground with brownish black postnotum and preepisternum.

Head. Antenna with 13 flagellomeres. Terminal flagellomere length 115-153 μm, conspicuous swollen apically and with strong sensory setae. AR 0.26-0.48. Temporal setae 5-9, including 2-4 inner verticals, 3-5 outer verticals. Clypeus with 7-10 setae. Tentorium 72-84 μm long, 14-19 μm wide. Palpomere lengths (in μm): 22-24; 24-26; 48-55; 60-65; 91-96. L: 5th/3rd 1.62-1.65.

Wing (Figure 24). VR 1.15-1.27. Anal lobe obtuse. Brachiolum with 1 seta; R with 4 setae; R4+5 with 0-1 seta; other veins bare. Squama with 0-1 seta. Costa extension 60 μm long. Cu1 slightly curved.

Thorax (Figure 25). Antepronotum with 4-6 lateral setae, dorsocentrals 6-9, acrostichals 0-1, prealars 4-6. Scutellum with 6-7 setae.

Legs. Pulvilli present. Spur of fore tibia 29-34 μm long, spurs of mid tibia both 17-19 μm long; hind tibia with a long spur 31-33 μm long, a short spur 19-24 μm long and comb composed of 10-12, 11 spines. Width at apex of fore tibia 21-26 μm, of mid tibia 21-24 μm, of hind tibia 24-29 μm. Lengths (in μm) and proportions of legs as in Table 10.

Hypopygium (Figures 26-30). Laterosternite IX with 3-4 setae. Anal point (Figure 28) subtriangular with round apex, 9-10 μm long and 24-26 μm wide, with 4-5 lateral setae and 2-5 long setae around the base. Phallapodeme 22-24 μm long. Transverse sternapodeme 43-48 μm long. Virga absent. Gonocoxite 77-89 μm long with reduced parallel–sided inferior volsella (Figure 29). Gonostylus (Figure 30) 43-50 μm long, expanded at the apex, crista dorsalis reduced. Megaseta 5 μm long. HR 1.60-1.83. HV 2.90-3.25.

Female, pupa and larva unknown.

Type materials.

Holotype: ♂ (BDN No.25207), China, Hunan, Hengyang County, Heng Mountain, 27°15'N, 112°51'E, 19.vii.2004, Chuncai Yan, sweep net. Paratypes: 2 ♂♂, Hunan, Dong’an Couny, Shunhuang Mountai, 26°24'N, 111°18'E, 26.vii.2004, Chuncai Yan, sweep net.

Etymology.

The specific name is from Latin, paucus, meaning “few”, referring to the new species has few setae on squama, R4+5 and acrostichals.

Remarks.

The new species resembles Pseudorthocladius (Pseudorthocladius) oyabecrassus Sasa, Kawai & Ueno, 1988 in the low AR (0.43, 0.50), gonostylus strongly expanded at about distal, but can be separated from Pseudorthocladius (Pseudorthocladius) oyabecrassus on the basis of characters in table 11.

Distribution.

The new species is known from Hunan Province in Oriental China.