The commercial growers use Lorsban which would require an annual spray of the entire trunk and large branch of every tree. If you are concerned about what winds up on the apples, I believe you can do this spray after harvest but you need to check the label.

I don't know if you can get any results from coating the wood at some specific time with surround. You should look up the life cycle of the pest. I get them in my nursery but they never kill anything although twice I've had bearing Bosc pears snap half way up the tree from injury. These were not nursery trees but larger ones already established- one of them in my own orchard.

I believe that more vigorous growing trees are less susceptible to serious damage.

Thanks, I will look into lorsban. Is this the only option or just the most preffered/effective?In reading MrsG thread on borers it sounded like this may not be available to hobyists.

My reasons for organic are many....some more rational than others. Certainly whats on the fruit is near the top of the list, but also longevity in the environment, as well as what it breaks down into, and effect on non-target species....after those it gets more philosophical "touchy feely" But despite how it might sound on another current thread, I don't live in terror of synthetics. I just want to start from the most benign options and work my way up until I find a balance that works.

I have read up on their life cycle and time my present methods of slurry and inspection accordingly but here I am...

So far I have never seen injury above 6" from soil line. The larva have always been found within 3" of soil line. And the 1 exit hole I have seen (apparently I am effective at getting them at larval stage) was just a bit higher. I have not had them on the pears yet, but I have far fewer of those.

rob
you should get a applicator license. In Maine you just get the booklet, take a general test then take a test for your specialty. (orchard, blueberry). To keep the license you need to take x number of credit classes every 3 years. here the classes are at the farm trade show so I am going anyway. It is a 3 day show and I pick a day when I can get 2 or 3 classes in. Plus I get to see all the new toys. So far the only restricted I use is velpar on my blueberry fields but I learn so much from the real orchard owners I don't want to miss a class. After 12 years of classes the only pesticide I could give advice on includes weight , windage, elavation, MV, and impact site. LOL At 55 I am sill a newbee.

If the borers you are getting are near the soil line you can probably protect the trees by wrapping with nylon screen held in place with rubber electric tape. Just push away the soil to the first roots and cover as high as needed and put the soil back.

Raven, While I am always interested in learning, I just can't justify that sort of commitment in time unless I find I am forced to use a lot more restricted treatments then I ever hope to. But never say never.

H-man, I have been told by other growers in the region (and read as well) that when using screen the adults either sneak behind it and you are more likely to miss early visual checks, or they simply move up and lay at the top of the barrier.

I have been thinking I may give it a try and see. But I am reluctant to disregard the advice and experience of folks with years on me and hundreds of trees who have "been there done that" and moved on to slurry painting.

Part of the frustration is that the damage I see is coming from 1 or 2 adults per year laying their 5-7 eggs (I assume). It's not like I am overrun with the damn things.

I've only heard it used for peach tree borers so maybe that's true. At least if it's higher up it won't kill anything.

rob the classes showed me I needed to do more IPM and did not need restricted. This year I cut down 40 trees, doubled the high quality crop, and sprayed less. In the classes I sit shut up and take notes. I am a mechanic by trade so I will make coments on the trade shore floor.

I recently learned of an organic-biodynamic method of making pastes of equal parts: cow manure, sand and clay. Then add water to right consistency. Apply the paste to entire tree trunk from base to first branching. This is said to help the cambium layer as well as stop insects from entry or exit from bark.

I haven't had a chance to try it yet but I plan on it.