The Indian Luna Moth Is Vanishing From Eastern Forests and Almost Nobody Is Watching

Actias selene, the Indian luna moth, does not eat as an adult. Its mouthparts are vestigial, fused shut by evolution. It emerges from its cocoon with one task: locate a mate before its larval fat reserves run out, a window that closes in roughly four to seven days. Every pale green wing, every long trailing tail, every eyespot on its 90 to 120 mm wingspan exists in service of that single compressed urgency.
This is a moth built entirely around reproduction, which makes the pressure on its habitat doubly destructive. When the host trees go, the caterpillars go. When the caterpillars go, the adults that emerge the following season number fewer. The species has no recovery buffer, no long adult life to compensate for a bad larval year.
The Indian luna moth ranges across the forested belts of northeastern and eastern India, the hill forests of Meghalaya, Assam, Sikkim, and parts of West Bengal and Odisha. Its caterpillars are host-specific feeders, recorded on Rhododendron, Ziziphus, Terminalia, and a handful of other tree genera. That specificity is a biological strength in a stable forest and a liability in a fragmented one.
Actias selene belongs to the family Saturniidae, the giant silk moths, a group that has been studied far more extensively in North America and Europe than in South Asia. The North American luna moth (Actias luna) has a body of published research, population monitoring, and conservation literature behind it. The Indian species shares the genus and the general biology. It does not share the research attention.

Three pressures are converging. Forest loss in northeastern India has accelerated alongside agricultural expansion and infrastructure development, shrinking the continuous canopy that Actias selene requires. Light pollution is a second, less discussed factor: nocturnal moths navigate and locate mates using light gradients, and artificial lighting from expanding towns and road networks disrupts that system at a fundamental level. Studies on Saturniidae in Southeast Asia have documented population declines in areas where artificial light at night has increased, even where forest cover remains nominally intact.
The third pressure is collection. Luna moths are among the most visually striking insects in the world, and specimens command prices in international markets. The Indian luna moth is listed under Schedule II of the Wildlife Protection Act of 1972, which prohibits collection and trade, but enforcement in remote forest areas is inconsistent and the trade continues through online channels.

Invertebrate conservation in India receives a fraction of the funding and public attention directed at vertebrates. Tigers, elephants, and vultures have recovery programmes, legal frameworks, and public campaigns. Moths have almost none of this, despite occupying a critical position in forest food webs: as larval grazers, as adult pollinators of nocturnal flowers, and as prey for bats, birds, and small mammals.
The Indian luna moth has no dedicated population study. Its distribution map is incomplete. Its host plant associations in Indian forests are documented patchily, mostly through incidental collector records rather than systematic field surveys. The Zoological Survey of India has recorded it, but a recording is not a monitoring programme. The species exists in the scientific literature without anything resembling a baseline count against which decline can be measured.

This is the specific problem with ignoring invertebrates: by the time absence becomes visible, the data needed to explain it was never collected.
A forest where Actias selene is breeding is a forest with intact canopy, intact host tree populations, and low enough light pollution to allow nocturnal navigation. The moth functions as an indicator species in the way a doctor uses a secondary symptom, not the disease itself, but a reliable signal of what is happening underneath. Losing it does not just mean losing a spectacular insect. It means the forest conditions that produced it are already compromised.
The caterpillars of Saturniidae moths are also a food source for a range of forest birds during the breeding season. Remove them from the system and the effect moves up the chain quietly, without announcement.
The Indian luna moth is not a flagship species. It will not appear on a campaign poster. But the eastern forests that still hold breeding populations are telling researchers something, if researchers were consistently present to hear it. The wings are the signal. The silence around them is the problem.