Integrated pest management of scale insects requires monitoring female scale to determine when they produce eggs and ultimately when crawlers hatch. This is because crawlers are the most vulnerable life stage. They are tiny and do not have a waxy cover so they can be killed with horticultural oil or other products more easily. If you need some inspiration (or fear) to go out and flip a few scale covers consider these numbers: right now Oak eriococcin scales, Eriococcus quercus, are full of what looks like hundreds of eggs. Emily Meineke found that oak lecanium scales, which are full of eggs now in Raleigh, produce around 2000 eggs each. In the same paper though she through a wrench in the monitoring scheme. She found that trees in warmer sites throughout a city produce eggs a couple weeks earlier than trees at cooler sites. So, the scales you monitor outside your office may hatch earlier or later than other scales a few block away. You can’t be everywhere so I suggest monitoring the warmest sites so you have some warning before scales on the other trees hatch. This is why I monitor azalea lace bugs near warm AC units on campus. Good luck!