Hello,

What you saw was probably a night crawler, Lumbricus terrestris. They are fairly common in the Palmer area. They can be very numerous in hay fields and farms, but many urban lawns will have them as well. 

I assume you had your trees were sprayed for sawflies, not straw flies. They sound similar, or maybe it's autocorrect. Either way. There is no reason to spray a spruce for sawflies. There are very few pesticides which would work on them, and getting the pesticide onto the bug is very difficult. Although some years they can be numerous, trees can usually handle the damage. If they are sawflies, good sanitation around the trees in the fall will remove many of the overwintering larvae and help to reduce the population for next year.