The pea moth (Grapholita nigricana), is a common pest of peas in Europe.
Infested pods are difficult to identify as the small entrance holes of the larvae are difficult to see. The caterpillar can damage up to four seeds in one pod. Damage only becomes obvious when plants are ripening and the emergence holes are seen or when fresh pods are opened. Vegetable peas are unmarketable if the infestation exceeds 0.5%.
The adults have a wingspan of 12-16 mm and olive brown forewings with black and white bands on the margins. The larvae measure 13-18 mm when fully developed They are initially white and later turn yellow with dark dots at the base of the hairs and a brown head.
The adults lay eggs on flowers or leaves of pea in June and July. Eggs hatch after 1-3 weeks and the larvae bore into the young pods and feed on the seeds for about 3 weeks. Thereafter, they leave the pod to overwinter in a cocoon in the soil. Pupation takes place in spring and the adults start to emerge in May.