Upon giving some general advice on summer pruning related to European White Birch, I was presented with cautions to avoid anytime but early dormancy to prune these trees, so as not to attract BBB to fresh wounds. I searched around to learn about BBB, but I have not found any reference to its presence in Northern California. Does anyone out there know if this insect is generally present in this neck of the woods? Also, if the pruning cuts were otherwise in accordance with current standards, would anyone recommend summer pruning of birch (or Beech)? My understanding is that BBB is attracted to the scent of fresh wounds and trees in a stressed condition. The egg laying is in the bark, and larvae tunnel their way in, so it doesn't seem that the cuts are the main entry point. The literature points to drought and other stress as main initiators to BBB infestation, with entry often occuring in the upper (more tender?) section of the trees. How big of a risk is it to summer prune birch(minimal directional pruning using thinning cuts), as long as other stressful conditions are avoided?

Reply to post by Mark Goodwin, on March 14, 1999 at 22:11:26:

I just read that BBB was found infesting trees in the Santa Rosa area. The sanitation measures used elsewhere apply here, including the avoidance of pruning April to July.