The Lesser Atlas Moth: Snake It 'til You Make It!

I honestly believe that I was INCREDIBLY fortunate to have spotted this gorgeous Lesser Atlas Moth while on a bike ride beside the Shing Mun River in April of 2023.

Truth be told, I've seen many a fascinating sight by the Shing Mun River, from snakes to terrapins and even huge egrets. But, coming across a Lesser Atlas Moth - especially during the day - has been the highlight of four years of continuous biking up and down the river.

The moth pictured was in the process of laying eggs, but since eggs are usually laid on specific trees so that the larva can feed after emerging from their eggs, I suspect the larvae that emerge from these eggs will have a much harder time surviving due to the lack of immediate food available.

The female moth I photographed was also likely on the verge of death or already perished. The adult life of adult Lesser Atlas Moths is pretty tragic and short.

1. Impressive Size

The Lesser Atlas Moth has a wingspan that can reach 21-23cm at its largest. This makes them one of Hong Kong's largest moth species, slightly behind the Atlas Moth, which can have a wingspan of up to 25.5cm.

2. They Can't Eat as Adults

Lesser Atlas Moths have underdeveloped proboscises (mouth parts), which are useless for feeding. They rely on fat stores from their caterpillar stage to sustain them as adults. As an adult, the sole purpose of the Lesser Atlas Moth is to mate before dying - usually within 1-2 weeks of emerging from their cocoons. During this time, females release a hormone to attract male moths, who can detect the scent from several kilometers away. The actual act of mating can last up to 24 hours, which is possibly 1/7 of an adult moth's life! Sadly, when a female lays eggs, she dies almost immediately after.

3. They Mimic Snakes as a Defense Mechanism

The wingtips of Lesser Atlas Moths resemble the heads of snakes to prevent birds from snatching them up. Since these moths are very clumsy fliers, they have little to no chance of avoiding agile predators. This is where their stunning wings helps to ensure their survival. The wingtips are so realistic that the 'eyes' are even convex, making their serpentine illusion all the more convincing. If threatened, they will drop to the ground and quickly flutter their wings, making it look like the thrashing machinations of a snake. In Hong Kong, they are often called 'Snake Head Moths' because of their wings.

4. They Look Like Maps (Apparently)

The 'Atlas' in Lesser Atlas Moth refers to the map-like striations and patterns that run down the outside edges of their wings. Personally, I think the local Hong Kong name of 'Snake Head Moth' is much more apt.

5. They're Completely Harmless

Though they look impressive and perhaps even scary to some because of their size, the Lesser Atlas Moth is actually completely harmless. If you see one, take the chance to admire their beauty rather than being afraid of these wonderful insects.

Lesser Atlas Moths can be found in a number of locations in Hong Kong including Tai Po Kau Nature Reserve, Kam Shan Country Park and Tai Mo Shan Country Park. Lesser Atlas Moths are nocturnal, meaning that if you want to see one in its natural habitat, you'll have greater success at night.

If you do chance upon a Lesser Atlas Moth, please treat it with respect. Do not try to touch or bother it and appreciate it from a distance so as not to disturb it.

This, after all, is one of those species that reminds us Hong Kong city folk that we are blessed to have such amazing wildlife even in today's modern age.