I really wouldn't have thought this would be a bad year for rust mites. After all, everyone was hoping that with such a hard winter, there would be fewer pests.
Looks like we were wrong!
Rust mites are cropping up in many fields. They will probably limit the number of fields that can go without an insecticide treatment this spring. But don't just assume you have to treat. Scout first! Twig aphids are now mostly hatched and even spider mites are hatching out. So scout and determine what you need to do.
From my pest management survey, I've learned that a lot of people are depending on either a bifenthrin product such as Sniper and/or dimethoate in the spring for pest control. But with rust mites so bad, neither product is probably the best choice.
Miticides such as Envidor provide a lot longer control of rust mites and spider mites both. Though more expensive, you can treat and pretty much walk away from the situation. So if mites are the only problem and you don't have twig aphids because of a fall treatment, consider just using the Envidor without mixing another product in. That will protect your natural predators.
I also think that bifenthrin is a much better product to use in the fall for Cinara aphid and twig aphid control. Then it should have much less effect on the parasitic wasp that controls the elongate hemlock scale.
The following links will provide help for mite control, twig aphid control and/or scale control.
controlling pests without hurting bees.
If you have any questions, please let me know.