Onion thrips (Thrips tabaci) develops in six stages: egg, two larval instars, prepupa, pupa, and finally the adult insect.
The eggs of the onion thrips (Thrips tabaci) are laid in leaves, flower petals and in the soft parts of stalks. They are inserted into the plant tissue with a saw-like ovipositor. Larvae are light to yellowish green in colour, with a large head and bright red eyes. The colour of the adult depends on the food source.
Onion thrips (Thrips tabaci) usually pupate in the ground, although pupae can also be found on leaves, in flowers or in other sheltered places. The prepupal and pupal instars can be recognized by their developing wing buds. Compared with the prepupa, the pupa has longer, more developed wing buds and longer antennae that are curved back over the head. The prepupal and pupal instars do not feed and only move if disturbed.