Bees and Trees

Monday July 23, 2012


Mr Pest Control


What is the best way to control wood boring bees? I have a client who has them and they are killing her tree.

Ken, AZ

Mr Pest Control


I am a little skeptical that the bees are the cause of a tree suffering badly. The only real wood "boring" bees will be carpenter bees, and these guys tend to restrict their burrowing to dead wood. It is possible that this tree does have some dead branches or perhaps a dead area on the trunk that the female carpenter bee has discovered, and she now is creating tunnels in it to raise her young. But, except for perhaps some minor digging where the dead wood of the tree might meet some live tissue it should be restricted to already dead wood. 

Leaf cutting bees are much smaller kinds of bees, some about the size of honeybees and others half that size, that often find existing holes in wood or stucco or other outside materials and the female takes over that existing hole as a convenient place to create her tubes of leaf pieces in which she then deposits and egg and some food for her offspring. If the hole is not quite large enough and the wood is soft she may enlarge it slightly, but again this is almost always going to be in an existing hole at the surface. These and some other kinds of small bees will get into the dead canes of roses and other narrow branches with a soft interior and do much the same thing - clean it out enough to create a small chamber for their offspring. But, in general they do not damage the plant. 

Hopefully I am correct on this and that the bees you are seeing are a red herring, with some other actual cause of the tree's problems. It would be important to get a positive and accurate ID of these bees so that you then will be able to determine what their biology is and their relation with that tree. If they are having nothing to do with it other than nesting in existing cavities then you would then have to analyze the problem more to determine the actual cause. 

Mr. Pest Control

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