Friday, April 4, 2008

Twig girdlers- amazing creatures!

When I first started with Extension, someone brought in a bag of twig tips that appeared to have been sawed off, very neatly. This led to my discovery of twig girdlers. I had a few questions this week on twig girdlers, so I thought I'd add information here so more people could learn about these cool beetles. Yes, they can be somewhat of a pest when they are munching on your tree, but you really have to admire their precision.

Twig girdlers are a type of longhorned beetle (they get the longhorn part from their long antennae, not because they are affiliated with UT, or should I say TU for all those good Ags). After mating, the female beetles chew a circular notch around twigs or small branches of the tree. Eggs are laid into notches chewed in the bark above the circular notch. Larvae hatch and tunnel under the bark of the twig.

Since the beetle "girdles" branches, the tips eventually die and fall off the tree. This is usually when I get phone calls since branch tips are "mysteriously" dropping from the tree with no visible insects (hint: the insects are inside the branch tips). Unfortunately, it is very difficult to catch the beetles in the act, so spraying really does not help manage the beetles. Sanitation is your friend- clean up and dispose of the twigs and small branches that have fallen off the tree as they contain larvae.

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