Psectrocladius (Mesopsectrocladius) wangi Liu, 2025

Psectrocladius (Mesopsectrocladius) wangi Liu sp. nov.

Figs 1 View Figure 1 , 2 View Figure 2 , 3 View Figure 3

Material examined.

Holotype: • male ( TJNU No. 04724), China, Fujian Province, Fujian Agriculture and Forestry University , 26°05'17"N, 119°18'43"E, 22.IV.1993, X. H. Wang, light trap GoogleMaps . Paratype: • two male, same data as holotype GoogleMaps ; one male, China, Guizhou Province, Fanjing Mountain protection temple , 27°55'N, 108°41'E, 28.V.2002, R. L. Zhang, light trap GoogleMaps ; • one male, China, Fujian Province, Shanghang County, Gutian Town . 25°13'28"N, 116°49'23"E, 4.V.1993. X. H. Wang, sweep GoogleMaps .

Diagnosis.

The anal tergite is wider at the top and narrower at the bottom with a rounded posterior margin. The anal point is short and rounded at the tip, thumb-like. The femur setae are thick, resembling spines.

Description.

Male (N = 5, unless otherwise stated in brackets).

Total length 3.37–3.88, 3.56 mm. Wing length 1.78–2.10, 1.92 mm. Total length / wing length 1.75–1.96, 1.86. Wing length / length of profemur 2.08–2.28, 2.23. The thorax is yellow-brown with brown markings, scutellum and the posterior half of the scutellum are lighter in color. The abdomen is brown.

Head (Fig. 1 C View Figure 1 ). AR 1.66–1.78, 1.72. Temporal setae 14–17, 15; including 3–7, 6 inner verticals; 4–9, 6 outer verticals; and 6–10, 8 (3) postorbitals. Clypeus with 21–37, 29 setae. Tentorium 139–172, 160 μm long. Palpomere lengths (II – V in μm): 51–75, 62; 81–117, 94; 78–107, 91; 121–151, 137; The ratio of the length of V to III: 1.29–1.62, 1.43.

Thorax (Figs 1 B View Figure 1 , 3 B View Figure 3 ). Antepronotals with 5–12, 9 setae, acrostichals 5–7, 6, dorsocentrals 17–28, 23. prealars 4–8, 5. Scutellum with 6–12, 10 setae.

Wing (Figs 2 A View Figure 2 , 3 A View Figure 3 ). Anal lobe developed. VR 1.17–1.21, 1.19. Costa extension 36–49, 43 µm. The end of R 2 + 3 is between R 1 and R 4 + 5. Radius with 8–15, 11 setae. R 1 with 2–6, 4 setae. Squama with 13–17, 16 setae. Brachiolum with one seta.

Legs (Fig. 1 E – G View Figure 1 ). Tarsomeres without bristles, hind leg with long bristles. Front tibia with one spur, 75–85, 81 µm long. Mid tibial with 2 spurs, the long one 53–60, 58 µm and the other is one-third of it, 20–25, 23 µm. Hind tibia with one spur, 70–80, 73 µm long. The hind tibial comb with 10–14, 12 spurs. Tarsus I and II of mid leg with two pseudospurs. Tarsus III of mid legs with 0–1 pseudospurs. Tarsus I and II of hind leg with two pseudospurs. Tarsus III of hind legs with 0–1 pseudospurs. Lengths (in μm) and proportions of legs as in Table 1 View Table 1 .

Hypopygium (Figs 2 A, C, D View Figure 2 , 3 C, D View Figure 3 ). Tergite IX with 14–18, 16 setae located in the lower part of anal tergite equably. Anal tergite wider at the top and narrower at the bottom, and margo inferior smooth. The end of anal point smooth and as wide as the base of anal point, thumb-like. Transverse sternapodeme 125–150, 129 µm long centrally slightly arched, with prominent oral projections. Virga 73–85, 75 µm long, club-shaped. The dorsal volsella is salient, the ventral volsella is arc-shaped and bears a row of setae. Gonocoxite 272–315, 287 µm long, Gonostylus 111–148, 126 µm long, outer margin with conspicuous setal fringe. Megaseta 15–30, 24 µm long. HR 2.13–2.51, 2.46; HV 2.62–3.19. 2.85.

Distribution.

China (Fujian, Guizhou).

Etymology.

Named after Xinhua Wang, in honor of his contributions to the study of Chironomidae , noun in nominative case.

Remarks.

The subgenus Psectrocladius (Mesopsectrocladius) currently comprises two recognized species globally ( Ashe and O’Connor 2012): P. (M.) barbatipes Kieffer, 1923 and P. (M.) seiryuheius Sasa, Suzuki & Sasai, 1999 . These taxa exhibit distinct morphological characteristics that facilitate their differentiation. Psectrocladius (M.) seiryuheius is particularly notable for the complete absence of both anal point and virga, representing a unique apomorphic condition within the subgenus.

Comparative morphological analysis reveals that P. (M.) barbatipes shares certain similarities with the newly described species. However, it can be distinguished by several key characteristics: (1) the presence of a less developed and partially reduced anal point, and (2) a significantly higher antennal ratio (AR> 2.0, following Laville’s 1971 description). Furthermore, P. (M.) barbatipes exhibits distinctive chaetotaxy on its mid legs, characterized by exceptionally long setae, as evidenced by its high bristle ratio (BR> 3.0). This morphological feature suggests an adaptation potentially related to specific ecological requirements or behavioral patterns.