All the larval stages of tomato pinworm cause feeding damage to buds, flowers, leaves and tomato fruits. Young larvae generally feed on leaves giving them mining appearance. The older larvae directly bore into tomato fruits and leave behind pin size hole on the surface of tomato fruits giving them name as pinworms. In addition to direct feeding damage, injuries caused by pinworms serves entry points for other disease causing pathogens that can cause rotting of fruits. In case of severe infestation, pinworms can kill tomato plants as well as reduce the quality and yield of tomatoes.
The life cycle of tomato pinworms consists of four stages including adult, egg, larva and pupa. Of these four stages, only larval stage cause damage to their host plants, Tomato pinworm overwinter as pupae on the soil surface under the plant debris. Adult moths emerge from pupae within 6-7 days. After mating, females lay eggs on the lower surface of leaves. These eggs hatch into small caterpillars that start feeding on the buds, flowers, leaves and fruits. While feeding, caterpillars develop through 4 developmental stages and become mature in June. In Mature larvae the drop on the ground and then pupate in the soil. Under favourable conditions, tomato pinworm can complete one generation in a year.