First Indian record of Heleniella nebulosa Andersen & Wang (Diptera, Chironomidae): Insights into cryptic diversity and the phylogeny of the genus Heleniella Gowin

The chironomid genus Heleniella Gowin, 1943 is recorded from India for the first time based on an integrative taxonomic study of adult males from the Eastern Himalayan Biodiversity Hotspot, West Bengal. The specimens are identified as Heleniella nebulosa Andersen & Wang, 1997 based on morphological characters and redescribed with a COI barcode. We include an identification key to the males of all Heleniella species, which provides a concise framework for distinguishing all known species globally. Morphological cladistic analysis based on 38 discrete morphological characters of adult males recovered Heleniella as monophyletic and placed H. nebulosa within the spotted-wing species group. COI-based phylogenetic and species-delimitation analyses (ABGD, ASAP) revealed the Indian population as a distinct evolutionary lineage, showing 12.29% sequence divergence from East Asian populations, suggesting a candidate cryptic lineage and extending the genus’ known distribution.