About 35 years ago, thrips in North American and European production houses were limited to fairly innocuous species that were easily treated with Biological controls or, more frequently, with chemicals. The arrival of the Western Flower thrips was the harbinger of our current situation. In general, thrips are small, soft bodied arthropods that can fly (somewhat). They cause damage by scraping the plant tissue and by destroying the structure of the flowers’ ovum, which leads to damaged fruit or misshapen flowers. They cause considerable economic damage, especially in cut Orchids and cucumbers, but damage of devastating magnitude can occur over a vast range of plants.
Their physical characteristics help them considerably in their quest to destroy your crop. Being both small and soft bodied allows them to penetrate easily any commercially produced screen (including “no-‐thrips” screens). Being able to fly, albeit in a limited fashion, allows them to be wind dispersed. For the most part, their eggs are pushed into the plant material, keeping them safe from predators. The larval stages, when they are vulnerable, are relatively short term and mobile. They usually pupate off the plant, in the substrate, once again removing them from harm’s way and the adults are quick and adaptive. They are truly challenging pests.