Description of a new species of Stictochironomus Kieffer, 1919 (Diptera, Chironomidae) from China based on DNA barcoding and adult morphology

In April 2025, adult specimens of Diptera were collected in Henan Province, China., and based on an integrated analysis of DNA barcodes and morphology, a new species is formally described as Stictochironomus longtanensis Lei & Zhang, sp. nov. Adult males can be distinguished from all known congeners by a unique combination of morphological traits: a greater hypopygium ratio (1.98–2.11) and longer hypopygium (3.77–4.01), the presence of a white ring on the femur, the wing with a dark spot near the cross vein r-m, and a superior volsella bearing six bristles.

Adult females are characterized by a small antennal ratio (AR 0.37–0.39); the wing with a dark spot near the cross vein r-m; genitalia with two ovoid, transparent seminal capsules; and a large, elliptical, densely setose cercus. The average interspecific genetic distance of the new species with congeners substantially exceeds the established threshold for species divergence in Stictochironomus, providing strong molecular evidence supporting this novel species.

An updated taxonomic key to the known male adults of Stictochironomus from China is also provided.