most of the time when ambrosia beetles attach, it kills the tree. I have managed to save 2 trees by doing HEAVY pruning and getting small suringies and squirting insecticide in the bore wholes on lower trunk.

The only real solution for ambrosia beetles is preventing in early spring. Spray trunk and lower branches with Permethrin once a week. One they get in the tree, there is not much you can do (but prune and pray).

Eric,

About a month ago I received some trees from Burnt Ridge. A week or so after planting, I noticed some fine sawdust around the trunk of a plum that was fresh. I knew the beetles were back. The trunk was then wrapped in cotton cloth, drenched in a strong mix of permetherin, and wrapped with Saran wrap to prevent drying. After a week, the wrap was removed, and no fresh dust since then.
It is my understanding that the fungus deposited by the beetles kills the tree. I have mostly brown branches, with a few still green. Time will tell

Benny

Thanks, Benny and Outdoor, for the ugly truth. One more question: if most of the damage is to two major scaffolds and those are the ones that are wilting already might it help any to prune those branches out? In other words, will the fungus spread from those branches to the rest of the tree or is the fungus fairly limited to the site of attack? If it might help save the tree, I could prune these branches out, but if it won't make any difference to the rest of the tree, I'd like to give those branches a chance to fight it out, too (although if they're already wilting I suppose the battle may already be over.)

And I just thought of another question: why haven't I ever noticed problems from these beetles before? Is it possible they weren't around here before this year? The reason I ask is because I'm hoping the reason is that this is just a bad year for them and not the start of new and mounting problems I should expect. And that raises yet another question: which species do people even worry about protecting? I've seen figs and jujubes, and I've heard/read of persimmons, pawpaws, pecans, cherries, peaches, plums, dogwoods (which I assume includes cornelian cherries), Bradford pear (which I assume includes other pears, and in any case is the rootstock for my other pears), sweet potatoes... It's one thing if they ruin all my fruit (most of which seems so likely to succumb to other problems if not these beetles), but sweet potatoes! What are they going to do to my sweet potatoes? What other fruits have any of you had damaged?

Are there no cultural practices or helpful management strategies besides pesticides?

The jujube and fig both suffered cold injury before they were attacked, so I'm hopeful they might not have been attacked otherwise. The fig had major die-back from the winter, and the jujube had started to push growth in mid-April when we had back-to-back freezes down to 30 degrees (which doesn't seem that unusual but it burned things like a gingko tree that I haven't ever seen burned before -- it's also the first time I've lost my entire Asian pear crop.) I've seen jujubes advertized as late vegetating and therefore immune to cold events like this, and they've seemed later in the past, but the only fruits that I've never seen seriously affected by late spring freezes are (rabbiteye) blueberries and figs. The figs have surprised me, given their more marginal winter hardiness, but they've weathered late spring cold that has affected all sorts of much winter hardier crops.

"And I just thought of another question: why haven't I ever noticed problems from these beetles before?"

I'd definitely suggest dealing with them as aggressively as possible this year. I let them get a toehold last year when they attacked a couple of potted navel oranges. Both were heavily damaged by cold and I'd all but written them off, so I didn't investigate to determine what kind of borers that I was dealing with. I discarded one of the trees that was all but dead, but the other survived both the cold damage and the beetles. The beetles obviously reproduced (or more came in from outside my property), because my figs took a real hit this year. Now I'm worried what might be next...

"The jujube and fig both suffered cold injury before they were attacked, so I'm hopeful they might not have been attacked otherwise."

I've noticed a similar pattern. Last year, it was cold damaged citrus. This year, it was cold damaged figs...with one exception, that being a fig that I'd carefully protected and that didn't have any obvious freeze damage when I uncovered it this spring. If anything, it was the worst hit by borers, and I cut it all the way back to the ground in an attempt to control their spread. Interestingly, I have another fig just 4' away that was similarly protected, and it's been beetle free. Three other figs with significant cold damage were also attacked. Two I cut back to the ground, but I tried a new strategy on the third -- I inserted a thin piece of wire into the hole and wiggled it around like is usually done for peach borers. This worked pretty well, but I had to stay on top of it because new holes would appear (with decreasing frequency, though). While doing this, I also spotted and squashed 6-8 beetles on the trunk -- they're tiny little devils.