Kribiocosmus yini Dong & Tang, 2024, sp. nov.
Creators: name: Dong, Xue
name: Tang, Hongqu
Publisher: name: Zenodo
Year: 2024
Subjects: Biodiversity
Taxonomy
Animalia
Arthropoda
Insecta
Diptera
Chironomidae
Kribiocosmus
Kribiocosmus yini

description: Kribiocosmus yini sp. nov. (Figs 1–2)
urn:lsid:zoobank.org:act: DC5C7CD6-0263-4138-A5C7-ECE9499F5F8D
Material Examined. Holotype, M, CHINA: Yunnan Province, Mengla County, Menglun, Xishuangbanna Botanical Garden, Lyushilin, 27.iii.2023, light trap, leg. J. Yin. Paratypes: 4M, 1F, as the holotype; M, Guangxi Province, Napo County, a scenic spot at Laohutiao, 16.iv.2023, light trap, leg. Y. He & X. Dong; M, Guangdong Province, Maoming City, Mt. Yunkai, 20.v.2020, Malaise trap, leg. S. Luo; M (teneral), Hainan Province, Baisha County, Yinggeling NNR, Hongsheng village, 02.v.2012, leg. H. Tang.
Etymology. For the collector, Jiadong Yin, who supplemented several important specimens from Yunnan Province.
Description
Male (n = 6). Total length 3.5–4.1, 3.7 mm. Wing length 1.55–1.93, 1.80 mm.
Colour (Fig. 1A). Brown in general, with banded wing and dark ringed legs. Apex of last flagellomere dark brown. Thorax dark brown, slightly deeper in scutal vittae. Wing with two cross bands along the transect section, with an extension to the wing base through the Cu vein and partial anal cell, wing apex slightly pigmented. Leg darker mostly on femur and tibia of all legs, with narrow pale-yellow sections near each base. Tarsus on p 1 nearly pale yellow except brown apically, ta 2-5 gradually brown. In mid and hind legs, apical half of ta 1-3, and full length of ta 4 and ta 5 dark brown. Abdomen brown, sometimes, a faint longitudinal median band present in AIII–VI. Hypopygium brown in basal half and pale in the gonostylus.
Head. Frontal tubercle absent. Flagellomeres 1–12, 635–650, 645 μm; flagellomere 13, 400–420, 408 μm, apical seta 40–60, 55 μm. AR 0.50–0.65, 0.60. Lengths (μm) of Pm 1–5: 45–50, 49; 30–40, 33; 200–240, 217; 170–190, 181; 235–250, 244, respectively. Palp 3 and 4 robust, and palp 5 slender. Temporals 8–12, 10. Clypeus with 20–28, 22 setae.
Thorax (Fig. 2A). Scutal tubercle absent. Ac 18–23, 21, extending to the middle of scutum. Dc 8–13, 10. Humeral pit distinct, consisting of several small dark tubercles. Pa 3–4, 4. Sct with 6–8 setae.
Wing (Fig. 1A, E). Anal lobe reduced, VR 1.08–1.15, 1.12. R with 13–17 setae; R 1 with 11–13 setae; R 4+5 with 0–1 setae, other veins and cells bare. Square with 3–8 setae. Pulvilli well-developed, around half length of claws.
Legs (Fig. 2B). Fore tibia with curved spur, 60–80 µm long. Mid and hind tibia with fused comb, each comb bearing a short-curved spur, 25–35 μm long. LR 1 1.70–1.88, 1.82, LR 2 0.52–0.54, 0.53, LR 3 0.88–0.92, 0.90; BV 1 1.40–1.43, 1.42, BV 2 3.10–3.51, 3.29, BV 3 2.45–2.57, 2.52; SV 1 1.40–1.51, 1.47, SV 2 4.16–4.22, 4.19, SV 3 2.50– 2.59, 2.54.
Hypopygium (Figs 1B, 2D). Anal tergite bands absent, medially with 1–3 anal setae, distally with 6–8 marginal setae each side.Anal point 55–60 μm long, arrow-shaped distally. Gonocoxite lobes partially fused, with a digitiform distal part that is slightly more dorsal (SVo) and a low proximal pad-like lobe that is slightly more ventral (IVo). SVo 25–30 μm long, microtrichiose, bearing 4–6 long margin setae (Fig. 2D). IVo connected with SVo base, with 6–8 strong setae arising from the inner margin. Gonocoxite 145–170, 155 μm long. Gonostylus 70–80, 75 μm long. Hypopygium ratio 1.88–2.13, 2.07.
Female (n = 1)
Colour (Fig. 1C). As male except lateral vittae are slightly brown in posterior section.
Total length ca. 4.00 mm, wing length 2.35 mm.
Head. Antenna with 5 flagellomeres (Fig. 2E), Fl 1-4 320, Fl 5 140 μm long, AR 0.42. Lengths (μm) of Pm 1–5: 30; 25; 250; 200; 190, respectively. Temporals 12. Clypeus with 36 setae.
Thorax lost after barcoding, assumed similar to male.
Wing pattern as in Fig. 1C, F. VR 1.20. Vein setation: R with 12, R 1 with 15 and R 4+5 with 25. Squama with 10 setae.
Legs patterned as in male. Fore tibia with curved spur, 100 µm long. Mid and hind tibia with fused comb, each comb bearing a short-curved spur, 40–50 μm long. LR 1 1.81, LR 2 0.59, LR 3 n/a; BV 1 1.44, BV 2 3.50, BV 3 n/a; SV 1 1.43, SV 2 3.77, SV 3 n/a.
Genitalia (Figs 1D, 2F). Notum short and broad, 200 μm long, rami 60 μm long. Gonocoxapodemes gently curved, slightly fused medially, each enclosing a setal patch, bearing 25 setae. Coxosternapodeme strongly sclerotized, weakly curved. Gonapophysis VIII (Figs 1D, 2F) comprising elongate dorsomesal lobe, microtrichiose, and distinct broad ventrolateral lobe, microtrichiose with many simple medio-apically directed setae, larger than the dorsomental lobe. Apodeme lobe broad, hyaline, inserting between dorsomesal and ventrolateral lobes. Labia without microtrichiae. Gonocoxite IX small, with 5–6 setae. Tergite IX triangular, undivided, bearing ca. 50 setae. Postgenital plate triangular, small. Seminal capsule oval, 70–90 μm in diameter. Cerci relatively small, 140 μm long by 60 μm wide in dorsal view.
Distribution. China (Yunnan, Guangxi, Guangdong, Hainan)
Remarks. The combination of the wing pigment pattern and the form of the tibial combs and spurs match the concept of Kribiocosmus, while the volsella differs in that there is no complete isolated inferior volsella in the new species. In contrast, an elongated complete inferior volsella clearly is present in both reported species, K. ornatipes and K. kanazawai. Fused or reduced inferior volsellae can also be found in Fissimentum Cranston & Nolte, 1996 (Pinho & Froehlich 2011), but the wing pattern and fore tibial spur clearly differ. Hence, it is unnecessary to erect a monotypic new genus for the current species and we place it tentatively in Kribiocosmus. A molecular analysis and immature stage study are needed in the future.
description: Published as part of Dong, Xue & Tang, Hongqu, 2024, Kribiocosmus Kieffer (Diptera, Chironomidae) newly recorded in China, with description of a new species, pp. 277-282 in Zootaxa 5555 (2) on pages 277-281, DOI: 10.11646/zootaxa.5555.2.7, http://zenodo.org/record/14594690