Horniolus longitubus Tang, Huo et Chen 2025, sp. nov.

Horniolus longitubus Tang, Huo et Chen sp. nov. (Figs 2a–k, 3a–c) Etymology. The specific epithet is derived from the Latin adjective “ longitubus ”, referring to its long and slender penis. Diagnosis. This species can be separated from all the described species by the different appearance with a pair of significant dumbbell-shaped, bright yellow-orange markings on the elytra (Figs 2a–b), the slender penis (Fig. 2h) and the penis guide with prominent projection at apical part in lateral view (Fig. 2j). Description. TL: 2.64–3.11 mm, TW: 1.98–2.35 mm, TH: 1.29–1.50 mm, TL/TW: 1.32–1.33, EL/EW: 0.98– 1.05, PL/PW: 0.51–0.52, HW/PW: 0.62, PW/EW: 0.73–0.76 Body round-oval, moderately convex, dorsum covered with dense white pubescence (Figs 2a–b). Head reddish brown. Pronotum reddish brown (Figs 2c, 2f). Scutellar shield dark brown. (Fig. 2a). Elytron dark brown with a pair of dumbbell-shaped, bright yellow-orange markings, situated at the middle of elytra. Anterior edge of markings parallel to elytral base, extending to apical 1/7 length of elytra (Fig. 2a). Underside chestnut (Fig. 2d). Mouthparts and antennae light yellowish brown (Fig. 2e). Prosternum reddish brown with dark brown margin, covered with dense white pubescence (Fig. 2e). Mesoventrite dark brown (Fig. 2d). Metaventrite dark reddish brown, with larger punctures on each side than those in the middle, covered with white pubescence longer than those on dorsum (Fig. 2d). Legs reddish brown, covered with dense white pubescence (Fig. 2d). Head with fine frontal punctures near the eyes, 1.0–2.0 diameters apart. The middle of frons smooth. Eyes finely faceted, interocular distance about 0.53 times of head width. Pronotum with coarse punctures, larger than those near the eyes, 0.5–1.0 diameters apart. Elytra with punctures as the same size as those on pronotum, 1.0–2.0 diameters apart. Prosternal carinae Y-shaped with stem 1/3 as long as arm, arms broadly separated. Abdominal postcoxal lines strongly recurved and complete laterally (Fig. 2g), reaching 3/4 length of abdominal ventrite 1. Area enclosed by postcoxal lines coarsely punctate, broadly smooth along lines. Abdominal ventrite 5 in male with apex weakly emarginate apically. Male genitalia. Penis slender, long and tapering toward apex (Fig. 2h); apex of penis thread-like (Fig. 2i); penis capsule with long inner arm and short outer arm. Tegmen stout with penis guide slightly shorter than parameres (Fig. 1k); in lateral view, penis guide boot-shaped with parallel sided from base to 2/3 length, bearing a prominent projection at apical 1/3 length, then tapering to blunted apex (Fig. 2k); in ventral view, penis guide parallel-sided from base to 5/6 length, then tapering gradually to blunted tip (Fig. 2j); parameres narrow, slightly longer than penis guide (Fig. 2k), densely covered with long setae at apices (Figs 2j–k). Female genitalia. Coxites elongate triangular with several setae at apex; styli distinct with long setae at tip (Fig. 3c). Spermatheca intricately coiled (Fig. 3b). Type material. Holotype: male, No. SCAU (E)17574, CHINA: Guangdong: Dafengmen Reservoir, Paitan Town, Zengcheng District, Guangzhou City, 5. V. 2022, Liu ZW leg (SCAU). Paratypes: CHINA: Guangdong: 1 female, No. SCAU (E) 18001, Huanggang Peak, Maofeng Mountains Forest Park, Baiyun District, Guangzhou City, 5. IV. 2024, Huo LZ leg (SCAU); 1 female, No. SCAU (E) 18002, Huanggang Peak, Maofeng Mountains Forest Park, Baiyun District, Guangzhou City, 5. VI. 2024, Huo LZ leg (SCAU); 1 female, No. SCAU (E) 18003, Dalian Mountains, Maofeng Mountains Forest Park, Baiyun District, Guangzhou City, 5. VI. 2024, Huo LZ leg (SCAU). Barcode sequence. Two COI barcode sequences of Horniolus longitubus sp. nov. are uploaded to the National Genomics Data Center (NGDC), with sequence lengths of 1534 bp. These sequences were integrated into a single dataset, designated as CRA020755. The individual sequences are catalogued as SAMC4411879 (holotype, SCAU (E)17574) and SAMC4411880 (paratype, SCAU (E)18001). The raw sequence data reported in this paper have been deposited in the Genome Sequence Archive (Chen et al. 2021) in National Genomics Data Center (CNCB-NGDC Members and Partners 2022), China National Center for Bioinformation / Beijing Institute of Genomics, Chinese Academy of Sciences that are publicly accessible at https://ngdc.cncb.ac.cn/gsa. Distribution. China (Guangdong). Remarks. Although the holotype (male) and paratypes (females) were collected from different locations in Guangzhou, their external appearances were consistent except for the sexual characters. To further determine whether these female specimens belong to the same species as the holotype, we amplified the COI gene sequences of the holotype (SCAU(E)17574) and one of paratypes (SCAU(E)18001) and compared the genetic distances between them. The results indicated that the similarity of the COI gene sequences of the holotype and the paratype was as high as 98.761%. According to the results of Huang et al. (2020), a genetic distance of 3% can be regarded as the threshold for delimiting species in the Coccinellidae using DNA barcoding. Therefore, we consider that these female specimens belong to the same species as the holotype.