New micro-moth species found near Assam's Hollongapar Gibbon Sanctuary

A tiny moth collected near the Hollongapar Gibbon Sanctuary in Assam's Jorhat district has been described as a species new to science, Northeast Now reported on Monday.

The moth, named Apethistis minapaksha, was found during a field survey near Mariani. The description was published on Monday in the taxonomy journal Zootaxa by Kishore Chandra Sahoo, a scientist at ICAR-Indian Agricultural Research Institute (IARI), Assam.

A small moth with a hidden signature

The species has a wingspan of just 10.5 to 11.5 mm. Its wings are mostly soil brown with small dark spots along the outer edges, so to the naked eye it looks much like its relatives.

What sets it apart is the male's reproductive structure. Under a microscope, the valva shows a distinctive fin-shaped projection near its tip. The closest look-alike is Apethistis dentata, described from China in 2017, which shares a pointed process at the tip but lacks the extra fin.

That feature gave the moth its name: "mina" means fish and "paksha" means fin or wing in Sanskrit.

Counting the genus

Apethistis is a group of micro-moths in the family Autostichidae. Before this find, 18 species were known worldwide, eight of them in India. The new description takes the totals to 19 worldwide and nine in India.

How the study was done

The description is based on five male specimens: one holotype, the reference specimen for the species, and four paratypes. The researchers studied them under a stereo zoom microscope, prepared the male genitalia for examination and recorded the wing venation, a key feature in classifying micro-moths. The female has not yet been found.

The specimens are kept in the reference collection of ICAR-IARI, Assam. Abhijith K. P. of the institute helped with collection, and Jayanta Jyoti Sarmah guided the field survey.

Why it matters

The Hollongapar Gibbon Sanctuary, a small forest patch surrounded by tea gardens, is best known as home to India's only ape, the western hoolock gibbon. The new moth is a reminder that many smaller and less visible animals in Assam's forests remain undocumented, and the authors say the classification of several Apethistis species still needs closer study using museum collections.