There has been excitement at the Berkeley Castle Butterfly House this week as nine Atlas moths have hatched from their chrysalis since last weekend (21st August).

Last year none of the moths hatched at the Berkeley Tropical Butterfly House, but this year the pupae has proved far more successful.

The science

The Atlas moth (Attacus atlas) is considered to be the largest moth in the world and is found in the tropical and subtropical forests of Southeast Asia, and common across the Malay archipelago.

Their total wing surface area can be upwards of 400 square cm or 65 square inches). Their wingspans are also amongst the largest, from 25-30 cm (10-12 inches).

Atlas moths are said to be named after their map-like wing patterns and the extension of the forewing, bears a resemblance to a snake's head.

The moths are predominantly tawny to maroon in colour with roughly triangular, diaphanous "eyes" on both forewing and hindwing, bordered in black. Their bodies are hairy and disproportionately small compared to their wings.

Neither sex possess fully-formed mouthparts and therefore do not feed; throughout their one to two week adult life they survive entirely on larval fat reserves that they build up while they are caterpillars. Atlas moths are unsteady fliers and the do not stray far. Their sole purpose of life as a moth is to breed.

Meet the moths

The Butterfly House is open in September on Thursdays and Sundays, so if you want to catch a glimpse of the largest moth in the world, get down to Berkeley now, before their one to two week life span is over.