49.3411 BF1262a

Jumping Bean Moth Cydia deshaisiana

(Lucas, 1858)

---

Wingspan c. 20mm.

This intriguing species gets its name from the habits of the larvae. They feed inside the seed pods of shrubs of the genus Sebastiania, and are found mainly in Mexico. In late summer, the seed pods fall to the ground and split into three sections. The larva, when warmed, will twitch, causing the fragment of seed pod to jump with it. This behaviour has made these "Mexican jumping beans" a novelty item which are collected and exported.

It is thought that the behaviour is a mechanism to help the developing larva escape the hot sun and find a sheltered or shady situation.

The adult moth is a fairly typical Cydia, with a combination of grey and silvery markings.

In Britain, a small number of the adults have been caught, having emerged from imported beans.