Oh my! This is one of my favorite topics! The correct term for this is 'phenology'. I would be shocked if Va. Tech didn't have some sort of model for your state. I'll send you a whole google page...I see that Va. Tech has a link!

For your next search, use 'Phenology' as your key word, and you will come up with some more technical links!

Here is a link that might be useful: IPM and degree days

Wow! Lots'o'stuff! I guess knowing the right word helps a lot.

Thanks- now I have to try to sift through this stuff! It was interesting that there is a model for powdery mildew also. I'm thinking itmay help me predict when I need to start looking for spider mites and white flies- sometimes the population is large before I notice the damage.

great question!

The University of Maryland's Extension Service has a Bulletin EB 350 which talks in general term of insect commonly attacking different plant species and tells the number of generations per year as well the month(s) the insects begin to emerge. Different control strateries are discussed. There are also line drawings of the common insects.

My copy is 8 years old. The timing of insect emergence is kind of geared to College Park Maryland but would be appropriate for much of the mid-Atalntic area. The price is now up to $18.

Your state university might have a comparable publication.

Here is a link that might be useful: publication

I like the looks of that. I hope they'll sell one to a 'foreigner'

Money talks. (Grin). You might also check out your county extension office to see if they have a comparable publication. In that way you can examine it before you buy it.

Well, it took some sweet talkin' but they'll sell me one. I had to remind them to charge me shipping! (Sometimes I'm so honest it hurts!)