Hi Guys: I would appreciate any info you may have on pin Bark Beetles.
A client of mine has what I believe to be an onfestation
of them.I am under the impressi9n there is no control.Would a
micro injection with the Wedgle System do any good? Thanks in
advance. Bill

Reply to post by Bill Camper, on July 09, 1999 at 08:03:49:

Boy, I sure wish I could answer the wedgle question. I'm in the process of experimenting with that very issue.

Ultimately though, the best control measures available for Pine bark beetles, or any of the cambium feeders I deal with in the Inland Pacific Northwest, US; are cultural.

Adequate irrigation leads the list, especially on pines in a buffer zone between disturbed ground and undisturbed native stands. I'm talking about two or three deep soakings throughout the season, but the key one is when the beetles are emerging for their mating flight. Pines with adequate moisture are more likely to exclude the insects with pitch flow, or at least isolate them from one another. If the pitch-out looks kinda pink on Ponderosa Pine in these parts, it's getting a little bit too dry, I prefer to see fairly clear to yellowish coloration of pitch flow from insect entry sites. If there is nothing more than sawdust coming from the entrance holes, it's probably toast anyway, and no insecticide is likely to be mobile enough to be effective.

Prophalactic sprays are the recommendation of choice from the land grant universities for high value landscape trees. I question the wisdom of that.

Ensuring adequate organic material at or under the soil line appears to be key to supporting the fungal dominated soil ecology involved with woody plants, conifers in particular (See Elaine Ingham's work - Oregon State U.) A good layer of mulch sure couldn't hurt. Also, Elaine tells us that a good way to disrupt the fungal community in the soil is to mess with it; ie: cultivation, tilling, trenching, etc.

Capitalize on the proven point that bark beetles seldom attack healthy plants.

Mauget's Bidren capsules may prove of some use, if there is adequate moisture flow in the tree to move the stuff around.

Blue stain fungus is also a factor in pines with bark beetles. Same story as DED in elms. Similar fungus.

I didn't say it would be easy, but in a nutshell, that's what I have to offer ya, knowing as little as I do about your situation.

Always consult state and local authorities regarding pesticide use. Consult product labels and apply according to label instructions. No endorsement of any product is intended or implied. Any other disclaimer that is appropriate to keep my rear out of a sling is inserted here [ ].

Best regards,
KWK

Reply to post by Kerry, on July 09, 1999 at 08:03:49:

As to maintaining an organic layer, is alowing the duff to acumulate a good idea?To me it is a natural environment and should be left alone, even with if blight is present you have spores on cones and such.

I encourage people to not rrake up seasomal needle cast.

Reply to post by John S, on July 10, 1999 at 02:22:20:

Yeah, leaving normal forest duff is a great idea. The less we disturb it the better. Although, I'm not sure what blight you are talking about, I am becoming more convinced that species diversity in the microbial world does a lot of good in keeping disease organisms in check. We start getting predation etc., which I would guess would be especially good with a leaf blight situation, where forest floor organisms feed off of the foliar blight organism. The forest duff also helps keep spores from becoming airborne again once they hit the ground. If we've raked it off slick and smooth, there isn't much to resist the spores from going airborne again.

Best regards,
KWK

Reply to post by Bill Camper, on July 09, 1999 at 08:03:49:

I suggest cutting out the infested trees and taking them away.
There is an article in the recent J. of Forestry (www.safenet.org) July 1999, called, "A scentsible approach to controlling southern pine beetles: two new tactics using Verbenone" that I recommend you read. Peter

Reply to post by Bill Camper, on July 09, 1999 at 08:03:49:

I will try to be a little more specific.I am dealing with
5-7 foot Eastern White Pines. The tops are drooping.Upon
inspection of the cambial area oof these drooping limbs,we are finding the white
grubs. As many as 4-5 in some of the limbs.The trees are planted
in the rear of a 10 year old property.Ther are 40
trees spaced about 5 feet apart.Right now about 25% seem to be infected with the beetle grub.
Thanks,Bill

Reply to post by Bill, on July 09, 1999 at 08:03:49:

Are just the main leaders drooping? You may have white pine weevil, not bark beetles. Get a positive ID.

The weevils aren't deadly to the trees, but sure can disfigure them.