Okay, it looks like the codling moth is already starting to fly in Vancouver, Washington as of April 30th....and thus, perhaps, Portland. This seems to be a little earlier than usual. I didn't realize we had reached "biofix" already. I will quote some information from the htt://das.wsu.edu
website and give a very brief read on how I read this.....but in case I am wrong (quite possible) please register for that website yourself. My read is that the first generation codling moth is starting to fly and to lay eggs already. These eggs will start hatching by about May 10th at which time if someone applies a traditional insecticide (and no ovicide) and that that kills emerging larvae then those growers and homeowners need to be doing that at that time.
Anyway, the above is way too simple. Here is what website says for the Vancouver Washington site (Seattle is a little later):
Last Updated: 04/30/2013
Degree days since January 1st. = 235
(old: after biofix = 60 DD)
6% of CM adults should have emerged. No eggs have hatched, but they should start being laid at 225 DD (50 DD after biofix).
If you are going to use an insecticide that kills CM eggs (Intrepid, Esteem, Rimon), it should be applied between 225-325 DD (50-150 DD after biofix). Using an ovicide at this time allows you to delay the first larvicide application to 525 DD (350 DD after biofix). If you are planning to use an insecticide at an egg hatch timing then a repeat application of the ovicide is not necessary. If an ovicide only control program is followed (not recommended) then two additional applications at a re-treatment interval of 14 days should be used.
Egg hatch is imminent. 40% of CM adults should have emerged. Egg hatch should start at 395 DD (220 DD after biofix) and trap catch should still be increasing.
Insecticides that kill young CM larvae before they enter the fruit should be applied by 425 DD (250 DD after biofix). The timing of a repeat application depends on the residual activity of the product used. Every 20 DD delay in treatment results in 3-5% increase in egg hatch past 455 DD (280 DD after biofix).