I would like to resuscitate this topic, (rather than create a new one). I was innocent of the peril of RHAB in the past, until my trees started shedding their bark around their bases. (This is what happens if the borer eats all the cambium; the overlying bark eventually sloughs off.) Once I saw the light, I set about trying to save my poor trees by inarch grafting root sprouts, (when the tree is no longer drawing the sap, the roots respond by throwing up multiple sprouts). This actually seems to have been quite successful in some instances. But I still have the problem of eliminating the borers in other trees. I tried the poking-wire-into-the-hole process - a complete bust. I balked at destroying any more of the bark by hacking at it in an attempt to follow the burrows. And I hit on the idea of injecting insecticides into the holes with a syringe and needle - a couple of cc in each tree, highly focused, total quantity of poison added to the environment minimal, benefits surely exceeding harms.... And what is the alternative? If I don't go for the biggest guns I can muster, I won't have any trees left. (Oh, the rationalisations one has to create to assuage a guilty conscience.)
Now I would like to confess my sins and seek absolution. Is there, in fact, no alternative? Does smearing raw neem oil on the trunks really kill the critters? (Painting the trunks with clay in latex paint does make it easier to find the holes, but it doesn't have the slightest impact on the females laying their eggs in yet more trees). This isn't a matter of getting an increased crop of unblemished apples - it is literally a matter of life or death. Unless eliminated, (not just controlled or reduced), these critters will gradually wipe out my entire orchard. I can't afford to experiment with solutions which may or may not work . Does anyone have clear cut evidence of successful methods? And, if others have gone the route I used - injecting poisons into the holes - what agents did you use, and did they work? (Anybody got any experience with using moth crystals dissolved in vegetable oil? This has been proposed, and sounds plausible, (and a lot less toxic), but, as I say, I can't afford at this point to experiment. I need to
know that it works.)
Addendum: I just discovered that I raised this identical discussion a few years ago. (That's a major problem with growing old - you start repeating yourself). Anybody have anything new to contribute based on their experiences in the meantime?
Broomholm OrchardZone 5b in Nova Scotia
Edited 1 time(s). Last edit at 03/06/2016 03:02AM by David Maxwell.