Spraying can kill Pinyon twig beetle



Help! We have a pinyon pine that was planted 10–12 years ago. The bottom part turned brown a couple of years ago. We thought it might have been the ips beetle and aggressively sprayed for that, which seemed to keep the brown to the bottom and only on one side.

This past month or so, the tree has really turned more brown up toward the middle and top.

There is an adjacent Austrian pine that had some bug issues and turned brown. I sprayed all the pine trees for the scale beetle in early May.

The brown seemed to get worse over a month period. The tree is turning brown on the side that faces northeast and corresponds to the side of the Austrian pine that turned brown. The tree has always struggled just a bit compared to those surrounding it but generally had done well.

In this heat, the tree is watered once daily for about eight minutes with two drip spouts at the base of the tree. That is just for the past week with the heat. Before that the tree was watered every other day for about eight minutes. We have never fertilized the trees.

­­— Troy and Diane

Your description makes me think your tree could be dealing with pinyon twig beetle.

Pinyon twig beetle attacks the newest growth of the tree. This is a teeny insect that tunnels under the bark of pinyon pine.

Historically, their damage was limited to the very tips of the twigs; say the growth from the last year or two. This damage is really no threat to the overall health and survival of the tree, it just makes it look a bit bad. However, the past several years I’ve seen instances where pinyon twig beetle has damaged or killed off larger, even significant branches of a tree.

Besides the obvious degradation of the tree’s appearance, the loss of significant growth can place the tree under stress, giving problems like ips pinyon bark beetle an opening and leading to a much more serious problem. The spray schedule for pinyon twig beetle is the same for ips beetle: three sprays a year with 38 percent Permethrin. The first one about the first of April, again about the first of July and a final one about the first of October.

The way we’ve done these sprays for pinyon ips beetle is to spray inside the tree, concentrating on soaking the bark of the trunk and the main branches where ips beetle typically attacks. To control pinyon twig beetle, do the spray for ips then take a couple of steps back and thoroughly spray the entire tree, soaking all of the branches out to the tips.

Stress on the tree is an essential prerequisite for beetle attack, so concentrate on getting and keeping your tree as healthy and vigorous as you can. One thing I’d recommend from the information you gave me is to water your trees for a longer period of time (perhaps an hour or two depending on the output of the emitter) but do it less often (every five to 10 days).

Your goal is to deeply soak the soil down to 12 or 18 inches and then give the soil a chance to dry slightly before soaking it again. Don’t make any changes in watering now while it’s so hot; wait until it starts cooling down a bit to wean the tree off of that frequent, shallow watering.

I’d also see about adding some additional drip emitters out away from the base of the plant to provide water to the roots that are reaching out farther. Providing water to a larger area should greatly benefit the tree.
As to fertilizing, I don’t think that’s something I’d do. Pinyon don’t require much in the way of fertilizer.

One last thing. I’d prune the dead branches that are on the tree and put them in the trash. It will immediately help the appearance of the tree, and it also will remove some of those little monsters from the situation.

Dennis Hill is the nursery manager at Bookcliff Gardens, bookcliffgardens.com. Send questions to Bookcliff Gardens, 755 26 Road, Grand Junction 81506; or email .(JavaScript must be enabled to view this email address).


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