Two previously unknown species of moth fly have been formally described from China, joining a genus so obscure that only four species were previously known from the entire country. The new flies, named Thornburghiella sichuanensis and Thornburghiella yintiaolingensis, were collected in mountain reserves in Sichuan Province and Chongqing Municipality, and their descriptions come alongside two significant range expansions: the first Chinese record of T. singularis, previously known from India, and the discovery of T. xinjiangensis in Inner Mongolia, far from its original Xinjiang locality.
The work, published in the journal ZooKeys, also raises the number of Thornburghiella species recorded in China from four to seven and presents an updated identification key to all of them.
Thornburghiella belongs to the subfamily Psychodinae, the moth flies, a group of more than 2,000 described species in more than 100 genera. The genus itself has a convoluted taxonomic history: it was first described by Vaillant in 1973, but the name remained invalid because no type species was designated. It was finally validated in 1982 with T. albitarsis, a species originally described by Banks in 1895, fixed as the type.
The catalogue of the genus began with Ježek in 1992, who listed 35 species. Oboňa and colleagues expanded the count of known Palaearctic species in 2017, and by the publication of Ježek and colleagues in 2022 the total had reached 47. Kim and Kim added a Korean species in 2025, bringing the genus to its current tally of 49. Along the way, several names were shuffled: Duckhouse in 1987 showed that T. spinicornis as then understood actually covered two distinct species, distinguishable by the morphology of the male genitalia, and proposed the replacement name T. tokunagai for the older homonym. Following Curler and Moulton, T. spinicornis is now placed in a different genus, Stupkaiella.
The new species were diagnosed using classic taxonomic characters, chiefly the fine architecture of the head, antennae and male terminalia. Thornburghiella males can be recognized by a single row of strong sensory spines on the first flagellomere, ovate wings without a sensory fold, mostly simple conical gonostyli, and an aedeagal complex that is ovoid, angulate, or divided into elongate pointed extensions. In T. sichuanensis, the eye bridge consists of six facet rows and the first flagellomere carries six strong spines; the allurement organs, specialized thoracic structures, are boot-shaped in lateral view, and the gonostyli are long, slender and flat, measuring 2.56 times the length of the gonocoxites. The holotype male, collected in Wanglang National Nature Reserve in Sichuan at 2,403 meters elevation in July 2016, has a body length of 1.78 millimeters and a wing length of 3.22 millimeters.
Thornburghiella yintiaolingensis, from Yintiaoling National Nature Reserve in Chongqing at 2,410 meters, is smaller, with a body length of 1.3 millimeters and a wing length of 2.7 millimeters. Its eye bridge has five facet rows separated by about 3.46 facet diameters, its allurement organs are roughly oval in lateral view, and its gonostyli are broader at the middle and slightly bent, forming an obtuse angle, at 1.8 times the length of the gonocoxites. The surstylus bears 15 to 20 tenacula, tiny comb-like teeth, near its apex. The species name honors the reserve where it was found.
The descriptions include careful comparisons with close relatives. T. sichuanensis resembles T. melanderi in overall appearance and in having long, slender gonostyli and ejaculatory apodemes, but differs in its eye bridge, separated by about five facet diameters rather than two, its six rather than seven flagellar spines, and the distribution of its tenacula from the subapex to the apex of the surstylus. T. yintiaolingensis resembles T. itoi but can be separated by its eye bridge separation of about 3.46 facet diameters versus 1.5, six rather than five strong spines on the first flagellomere, and gonostyli that are narrow rather than wide at the base.
The two range records are equally consequential. A single male of T. singularis was collected in Nyingchi City, Tibet, in July 2017 at nearly 3,000 meters, extending the species’ known range from India into China. The specimen matches Quate’s 1962 original description in all critical features, including the seven facet rows of the eye bridge, the row of seven strong spines on the first flagellomere, large thoracic allurement organs, dark spots at the wing vein termini, and a long spear-like aedeagus; only the shape of the hypandrium differs slightly. Two males of T. xinjiangensis were found in Daqinggou National Nature Reserve in Inner Mongolia in August 2014, the first record of the species outside Xinjiang. They agree with Wagner’s 2003 description in the seven-row eye bridge, 14-segmented antennae, six long spines on the first flagellomere, short-stalked allurement organs, and 16 to 19 tenacula on the surstylus, with only minor variation in palpal ratio.
The collecting and preservation methods reflect standard modern practice for these fragile insects. Specimens were taken by sweep netting, immersed in absolute ethanol and stored frozen at minus 20 degrees Celsius. Heads, wings and genitalia were dissected separately, with abdominal tips macerated in glacial acetic acid and stored in glycerin-filled microvials. Specimens were examined and photographed with a Leica M205A stereomicroscope, with image stacks combined using Helicon Focus software, and all material was deposited in the Entomological Museum of Henan Agricultural University in Zhengzhou. For T. yintiaolingensis, the collection site was a small pool formed by converging streams and surrounded by abundant shrubs.
Before this study, Thornburghiella had been recorded in China only from Taiwan and Xinjiang. With the new species and records, its known distribution now spans Sichuan, Inner Mongolia, Chongqing and Xizang, covering both northern and southern regions of the country. The authors argue that this widening footprint, built from a handful of specimens collected years apart across vast terrain, is strong reason to believe the genus’s true diversity in China remains substantially underestimated, and that further field surveys and taxonomic revisions will be needed to uncover additional undescribed species hiding in the country’s mountains and reserves.
Subject of Research: Taxonomic description of two new Thornburghiella moth fly species and new distribution records in China
Article Title: Two new species of the genus Thornburghiella Vaillant, 1982 ( Diptera , Psychodidae , Psychodinae ) from China
Article References: Yang, S., Xi, Y., Wang, P., Yin, X., & Xi, Y. (2026). Two new species of the genus Thornburghiella Vaillant, 1982 (Diptera, Psychodidae, Psychodinae) from China. ZooKeys, 1296, 77-90. https://doi.org/10.3897/zookeys.1296.199004
Image Credits: AI Generated
DOI: 10.3897/zookeys.1296.199004
Keywords: Thornburghiella, Psychodidae, moth flies, new species, China, taxonomy, Diptera, Sichuan, Chongqing, Inner Mongolia, Tibet, ZooKeys
News Source: Drew Townsend. (October 29, 2026). Two New Moth Fly Species Discovered in China Expand a Little-Known Genus. Scienmag.
