Thrips

Again, there are as many species of thrips (singular – also thrips) as I’ve had hot dinners, and they are so small it is hard to know what species you’re looking at. Thrips generally aren’t too much of an issue for orchids but one type (Echinothrips americanus) can cause massive issues on flowers. They don’t seem to bother much with growths, but they love flowers, especially those of Cattleya and relatives, some Dendrobium and the fleshier types of Bulbophyllum. I have occasionally seen them on Coelogyne, but this is rare. They are small insects, about 1mm in length, white or tan when very young, orange when a bit older and the adults are brown with two spots on the back which you can see with a hand lens. Unlike other species of thrips, they aren’t really airborne as such so the blue or yellow sticky traps sold to trap them don’t work. The damage they cause is limited to flowers and occasionally root tips and this is really frustrating because flowers are the main reason we grow orchids. Spraying flowers is never a good idea so I mostly just remove infected flowers and dispose of them well away from the rest of the collection.