Last Thursday night  I was driving home from work in light rain and I could see dozens of large moths in the car headlights struggling on the road, with bright red eye shine. Then at home these chunky furry moths beat at the windows confused by our internal lights. It was a rain moth night!

Rain moths are in the family Hepialidae, the Swift and Ghost moths. Our most common species locally are the Labyrinthine Ghost Moth and the Bardi Moth, both in the Abantiades genus. We also have the smaller reddish moths in the Oxycanus genus.  The moths are famous for predicting rain – as the adults pupate and emerge collectively from their underground burrows just before rain. How they know – no-one knows.

Oxycanus sp moth on my hand 🙂

The caterpillars have been underground for literally years eating roots of their host plants  – which could be Eucalypts, acacia or grasses such as Poa.Their adult lives are extremely short – a few days at most. In fact, the adult rain moth has no mouthparts. That’s right – their final form is not about sustaining their lives as adults – it’s all about breeding!

The rain is the essential part of the equation, as after mating the females fly about in the light rain scattering their eggs into the rain drops like a beautiful moth sky seeding exercise.

Rain moths have the distinction of holding the “World Fecundity Record” for the greatest number of eggs deposited by a non-social insect – one researcher  counted 44,000 eggs in one female!

You can help our lovely rain moths, and indeed all of our local moths and insects by turning off external lights at night – sensor lights are a much more wildlife friendly option.

Bardi Moth by dhobern via cc commons