b'a large number of crops. Many kinds of thrips occur in The Netherlands, however, one single species is responsible for problems in horticultural crops. The problems they cause vary from sucking out of plant cells, as a result of which leaves die. Besides, a plant can react to this by providing rampant growth of tissue, which results in deformations of leaves. When leaves are sucked out, also viruses can be carried on. In strawberries especially Californian thrips (Frankliniella occidentalis) causes major damage.Test centre HoogstratenBesides Californian thrips also tobacco thrips (Frankliniella fusca) and rose thrips (Thrips fuscipennis) occur in strawberry cultivation, however, these species are less harmful. It is hardly possible to recognize with what species of thrips you have to do in specific cases. This is only possible if the thrips involved will be enlarged 250 times. Eggs are laid in plant tissue, both in flower bottoms and in leaves. Subsequently, the larvae develop in stages. This development also occurs both in the leaves and in the flower bottoms of the plant.In the prepupating stage the greater part of the thrips drop on the ground and look for some dirt or creep under plastic to 111'