Pest Problems Explained – THRIPS (Thunder Flies)

Thrip Description

Small, slender insects about 2-3mm long when fully grown. The adults have two pairs of narrow wings fringed with long hairs, the wings are held along the back when at rest.

Colours range from pale yellow to black, dependant on species.

Thrip Damage

Thrips feed on cell sap by piercing the leaf or flower bud with their mouthparts. These tissues then become mottled or flecked and are subject to dehydration, in severe cases they appear to have been scorched.

When leaves or buds expand they may become distorted or torn, forming “Windows” in the tissue.

Thrips can often be found in large groups near the veins on the under-side of leaves.

Thrip Life Cycle

A single female can lay about 60 eggs throughout the summer. Eggs are laid on the underside of leaves.

The larval stage lasts for about 10-14 days, after which the larva falls to the ground to pupate beneath the soil surface.

The pupal stage lasts between 4 to 7 days.

Biological Control of Thrips

Thrips can be controlled biologically by using their natural enemies such as the predatory mite Amblyseius cucumeris and several other species.