Attack of the Southern Pine Bark Beetles

I've got to share with you a somewhat funny story that is "so me" and yet directly related to this week's tip sheet. It goes like this - When I think of Southern Pine Bark Beetles I want to throw up!!! You see, in 1985, I was working for The Texas Farm Bureau, video taping a massive Southern Pine Bark Beetle infestation in the Sam Houston National Forest outside of Huntsville. We went up in a small, one-engine plane to shoot the video. After many (what seemed like to me) barrel rolls over the forest, I finally asked the pilot to land soon, so I wouldn't hurl in his plane. He didn't make it in time!

So, now you know that this week's tip is all about the southern pine bark beetle. I had noted both on my radio show and on my new Facebook Fan page as of recent days, that I had seen lots of what I was confident was pine bark beetle damage on way too many pine trees in the area. After plenty of emails also pouring into The GardenLine, on just this subject matter, I thought it was worth getting into some of the gritty details as I know them.

How do you even know if your pine tree has southern pine bark beetles to begin with? One quick way to tell is to find the pine trees with the most rust-colored needles. Those with 100 percent rusty needles are dead anyway. So, then the question may also be "what caused its death?" Was it southern pine bark beetles or drought??? Granted it could be from drought, but then again, many other trees in the area would be suffering the same effects, as opposed to this one-tree-at-a-time effect I see now. But if that one tree is more than half rust-colored needles, look at the base and see if you can find sawdust. If you see any sawdust, also look up at eye-level and see if you can find tiny little holes all over the bark. The holes will be small enough that one could only pop a grain of rice through and nothing bigger.

The beetles are about that size - the size of a grain of rice. And they are rarely seen but are of a darker brown to maroon to black body much like the color of a fire ant.
I will spare you the entomology of the bug and its biology, but note that they love stressed trees and boy have we had some stressed pine trees due to the '09 drought.

Pine bark beetles will attack the middle and upper portions of the body of the trunk of the pine tree. It is here where the adult bark beetles burrow and create tunnels in the meat of the tree. It also where the females locate and lay their eggs for hatching. I know I said I would avoid the entomological details, but hear me out on this. Once larvae hatch, they begin tunneling through the bark and feeding on it. It is through this process that they then pupate within the tunnels and emerge from the small holes as mature, adult bark beetles. The more beetles the more damage on that cambium layer of the tree, girdling the nutrient pathways and quickly killing the trees.

What can you do about it?

You have a couple of choices, and in the case of the highly-infected to already-dead pine trees, you really only have one choice, and that is to remove them. Let me repeat: If the tree is already and obviously dead, get it removed so it is no longer a temporary housing project for other pine bark beetles. If a tree is more than 50% rusted on the needles, it is nearly impossible to save, so it too needs to be removed. By the way, cutting it down but not removing the wood, is just as bad as leaving it alone. It's still the temporary housing project before they find the next stressed tree.

Now to the choices for control for the remainder of the pine trees which are still mostly healthy. And, oh by the way, there really is not a bonafide 100% organic control for pine bark beetles when it comes to "systemic control". I will give you a couple of ideas on how to stay somewhat organic but please keep in mind that if you truly want to save the trees in the long term, you need to use one of a couple of chemical treatments.

There are two systemic controls that work through the vascular system of the tree helping to prevent future damage to the tree, sort of immunizing itself against the insect pressure. Anything with Imidacloprid/Merit or any systemic Acephate-based insecticide will do the trick. There are systemic insecticides that you soak around the root and there are systemic insecticides that you inject into the tree's cambium layer. They both work systemically and help the tree defend itself from future infestations. But these are the preventative measures by definition. And there are many people out there that refuse to use such chemicals. Plus, since they are systemic by nature, they take over 30 days to do their work.

So, what if you catch the earliest of stages, but refuse such systemic action? You can treat the trunk with any number Permethrin-based insecticides. Many permethrin type products need to be used several times over a 60 day period for complete control. My guess is they will recommend at least two and possibly up to four applications in such a time. But as is always the case when using any insecticide (including organically-based ones) is to read the label instructions completely before applying. By the way, if your logic meter went off on the systemic control versus the contact control, you may be asking - "If it takes over 30 days for a systemic insecticide to work, should I spray the trunk in the interim as Randy just described?" Yes!

Organically speaking, there is no silver bullet when it comes to pine bark beetle (or any borer insect for that matter), but in place of Permethrin or various other synthetic pyrethroids, you can apply any Spinosad-based organic. Much like Permethrin sprays Spinosad is best used in the earliest stages of any pine bark beetle control. Some folks who are manic to the organic swear by this treatment even on non-infested trees simply as a 'preventative'.

Then again, the ultimate organic way to control pine bark beetles is to keep them from infesting the trees in the first place by maintaining the healthiest of trees. . Any guesses on how to do that? Keep the trees from stressing out in the first place, because remember the only pine tree a pine bark beetle likes in the first place is a stressed one. And how do you keep it healthy? You long-time GardenLine-faithful better have said the answer out loud by now - DEEP ROOT FEEDING/WATERING FOLLOWING RANDY'S TIP SHEET?.