Pagastia (s. str.) emakarchenkoi Liu & Tang, sp. nov.

http://zoobank.org/ urn:lsid:zoobank.org:act: E7DE097F-DD58-47E2-90A0-1259BBB937C7

Figs 1A–C, 2A–B

Type material. Holotype, Male, CHINA: Yunnan Province, Lijiang City, Yulong County, Laojunshan (shan = mountain) National Geopark; 19.iv.2024; leg. S. Ma; Dep. (EJNU). Paratypes, 1 Male, same as the holotype; 1 Male, CHINA: Yunnan Province, Dali City, Cangshan, Qingbi Stream; 15.iii.2024; leg. X.F. Li; Dep. (EJNU).

Etymology. In honor of Prof. E. Makarchenko, who has made a great contribution to the systematics of Diamesinae, especially the genus Pagastia.

Description

Male (n = 2–3).

Total length 6.3–6.7 mm. Wing length 4.0– 4.2 mm. TL/WL 1.55–1.66.

Coloration. Whole body dark brown or gray brown, including the thorax and legs.

Head. Antenna with 13 flagellomeres, total length of basal 12 flagellomeres 400 μm. AR 2.2. Temporals 58–65, including 45–50 inner verticals, 6–8 orbitals, and 12–16 postoculars. Palpomere lengths (in μm, n = 1): 70; 150; 250; 310; 370. Clypeus with 50–60 setae.

Thorax. Lateral antepronotals 25–30, median antepronotals 12–15; acrostichals 30–40, dorsocentrals 36–42, robust in two rows in anterior and posterior 1/3; anterior prealars 10–15, posterior prealars 18–25, more dense than anterior; scutellars ca. 140, irregularly arranged in 4–5 rows.

Wing. Arculus with 4–5 setae. R with 30–32 setae; R 1 with 15–18 setae; R 4+5 with 3–5 setae; squama with 90–95 setae. VR 0.86–0.92.

Legs. Spur of fore tibia 120–140 μm long, basal 2/3 divergent; spurs of mid tibia 85–100 and 90–100 μm, basal 4/5 divergent; spurs of hind tibia 60–80 and 105–120 μm long, basal 4/5 divergent. Hind tibia comb with 12 setae. Lengths and proportions of legs in Table 1.

Hypopygium (Figs 1A–C, 2A–B). Tergite IX with 25–30 setae on each side. Laterosternite IX with 15–18 setae. Anal point small triangular, 20–25 μm long and 15–16 μm wide in base (Fig. 1C). Aedeagal complex consists of a mitten-shaped median lobe (MAL), with a small dorsal branch (MALb), apex pectinate. Lateral aedeagal lobe (LAL) slender, with a brush apically (Fig. 2A–B). Gonocoxite 345–360 μm long, gonostylus 248–250 μm long. Megaseta 15–20 μm high, clearly extending beyond the inner margin of gonostylus. HR 1.38–1.44.

Remarks. In the latest key to the known Holarctic species of Pagastia (Makarchenko & Hansen 2020, p. 175), the new species keys to couplet 5, P. orientalis / P. altaica, but the anal point of the new species is stout, triangular, and fully sclerotized (Fig. 1C), which clearly differs from other known members in this genus. Furthermore, the median lobe of the aedeagal complex is also unique, which consists of two parts: the mitten-shaped main body and a dorsal branch which arises basally on the median lobe. The apex of the lateral lobe is also pectinate. Currently, the species is only known from Yunnan Province.