Dennis, If it is thrips, you have to see greyish really small spots on the leaves (no web, if you have a web it is spidermite!), thrips sucks cells out they get filled with air that is why it looks gray or slivery. Thrips are hard to kill. They have a 2-4 weeks of not feeding stages in the soil, so if you use chemicals you have to re-apply in 7-10 days again, moreover there are a lot of resistent types. Their life cycle is depending on the temperature, on room tempearute 3-4 weeks needed for 1 cycle. In the US you may use talstar, conserve, botaniguard (this is a bacteria), or predatory mites. These are contact insecticides, they are cheaper thn systemic. You may also try to use 1 systemic like Avid, in every second week, prepare that you may have to re-spray your plants 3-4 times! Jan