Thrips

Thrips
Onion thrips
Scientific Classification
Kingdom:	Animalia
Phylum:	Arthropoda
Class:	Insecta
Subclass:	Pterygota
Superorder:	Exopterygota
Order:	Thysanoptera
Synonyms
Thrips Thunderflies Thunderbugs Thunderblights Storm flies Corn lice

Thrips are tiny, slender insects with fringed wings. Thrips species feed on a large variety of sources both plant and animal by puncturing them and sucking up the contents. A large number of thrips species are considered pests, because they feed on plants with commercial value. Thrips like tight spaces for hiding and feeding and, with regards to onions, are usually found in the neck or folded leaves.

Symptoms

A heavy infestation of thrips will cause sufficient damage to the leaves to reduce photosynthetic ability and, as a result, reduce any fruit yield. Silvery-white streaks are noticeable on the petals.

Fruit damage varies depending on the crop:

• Cucumber - An infestation results in distortion and curling of the fruit, white linear markings are visible.
• Pepper - Silver or brown streak spots are visible on the fruit. Feeding on sweet pepper causes silvery or bronze streaks or spots on the fruit. The sepals may also curl due to thrips feeding and expose the fruit to infections.
• Tomato - Ghost spoting may be visible if feeding has occured on the fruit. This may also occur on cucumber and pepper fruit.

Examples

Onion

Damage to an aubergine

Thrips visible on a cabbage leaf

Damage to a cabbage head

French bean

Cucumber (Western flower thrips)