Cydia saltitans

The moth lays the egg on the young capsule. The hatched larva gnaws into the fruit, which closes the minute hole during its growth.The larva attaches itself to the capsule with many silken threads by hooks on its anal and four hind abdominal prolegs. When the fruit is warmed, for instance by being held in the palm of the hand, the larva twitches, pulling on the threads and causing the characteristic hop. "Jump" is often an exaggeration, but the beans nonetheless do move around quite a bit.

The larva may live for months inside the fruit with periods of inactivity. It eats away the seed inside the capsule, making a hollow for itself. If the fruit is cut, the larva will repair the hole with silk.

If the larva has suitable conditions such as moisture, it will live long enough to go into a pupal stage.In preparation for this, it eats a circular hole through the shell and closes it again with a silken plug. This is to enable the jawless adult moth to escape from the fruit. After completion of the exit hole it spins a cocoon within the fruit, with a passageway leading to the opening. During the following pupal stage the larva will not move any more.Normally in the spring, the moth will force its way out of what remains of the fruit, through the round "trapdoor", leaving behind the pupal casing.

The small, jawless silver and gray-colored moth will live for only a few days.