“…The Rain moth’s name stems from the fact that adult moths often emerge after rain during the autumn months of March and April. They are also known as the Swift moth, a name that reflects its short and final life cycle. Astonishingly, the Rain moths will only live for one day; for 24 hours their sole role in life is to mate and, if female, to then lay eggs. The moths cannot feed or drink because they don’t have the appropriate mouthparts to do so.

The female Rain moth has the highest recorded egg laying capacity among non-social insects. One female was reported to lay 29,100 eggs, and when dissected 15,000 fully developed eggs were found in her ovaries. That means she had the potential to lay over 44,000 eggs! A female rain moth lays her eggs, singly, while f lying, ‘bombing’ them in the general direction of the roots of gum trees, allowing the rain to wash the eggs into crevices in the ground, along with dominant seeds that will germinate, so that when the eggs hatch the young caterpillar larvae can easily find fresh soft roots on which to feed. And, the more eggs she lays during her short life, the more chance there is that some hatching larvae will survive to find food and start a new generation.

Larvae (also called a bardee) are large grubs that can live in the ground for many years, feeding on acacia and gum tree roots. The newly hatched grubs will burrow further into the ground where they continue feeding on tree roots. As they grow larger, their burrow, in which they live, will also become progressively larger, up to several centimetres in diameter. Bardee grub holes can be distinguished by the lining that somewhat resembles felt. After several years the larva (caterpillar) will pupate under the ground in their tunnels and the mobile pupae wriggled towards the surface waiting for rain. The evidence of their recent emergence from the ground is given away by the presence of these discarded skins at the entrance to their now empty holes after rain.

Rain moth is a great name for this moth because the adults only emerge from their pupal tunnels when rain is imminent. They are a vital part of the web of life where for every creature there is another creature that will try to eat it. Rain moth larvae are reasonably safe in their underground tunnels, but emerging moths are vulnerable to the attack of flying creatures, such as the night’s insectivorous bats and the Tawny Frogmouth owls…”

From Tom Parkinson, Nature’s Rubik. www.sanctuarylakesresort.com.au