- Common Name Thrips / Thunderflies
- Scientific Name There are many types, including Glasshouse Thrips (Heliothrips haemorrhoidalis).
- Areas affected A wide range of plants.
- Timing Thrips emerge in Spring and the females lay eggs that hatch within days.
What Are Thrips?
Thrips are a very small narrow bodied insect also known as 'thunderflies', to be able to see them clearly you really need to use a magnifying glass or hand lense. Thrips can be different colours but have two pairs of wings which fold back over its body. The young nymphs do not have wings and are paler in colour than the adults. Each female adult can lay up to 80 eggs at a time, they do not need a male to reproduce and their eggs will hatch in a few days during warm weather.
What Damage Do They Cause?
Thrips can damage leaves and flowers as they suck the sap from the cells. The leaves can lose their green colour and will have a silver/white colouring to them. It is also possible to see black frass (insect excrement) on the feeding marks. The flowers will begin to grow distorted and white marks can be seen where they thrips have been feeding. If the infestation is particularly heavy, the flower buds may not open at all.
As thrips are sap sucking pests, viruses can be transmitted in the mouthparts of the aphids. Thrips tend to be more of a problem under glass but can still cause damage outside, they can be found on a huge range of plants such as onions, peas, gladioli and other flowering plants.