I saw my first Fraser fir with buds breaking yesterday. So ready or not, it's spring!
The weather hasn't cooperated much in getting spring pesticides out. If you got behind and buds are breaking and you need to control twig aphids, an application of Dimethoate should control the aphids even in the broken buds. This will also knock back spider mites and rust mites. This works best when applied with a high pressure sprayer -- not with a lot of pressure, but with good coverage of all the new growth. However, even with a mistblower, it still may help.
So far this spring, though, I haven't seen many fields with enough twig aphids to worry about. With all the rain we're getting, it will greatly lessen the impact of twig aphid damage and spider mites as well.
The key is to not forget the spider mites as the summer progresses and especially if the rains stop. Late season spider mites can sneak up on you. Even if you use a good miticide in the spring, that is no guarantee that spider mites won't become a problem again by late summer or fall. Even a quick job scouting is better than not looking at all.
I guess the point of this post is to not worry if you haven't gotten all the insecticides you intended to before bud break. It is better to not apply a pesticide than to put it out in poor conditions such as too windy or rain on the way. Just keep an eye out for developing problems. Nine times out of ten, pests like twig aphids and mites won't be bad enough to worry about.