Archive for Thursday, June 5, 2008

Carpenter bees may cause structural damage to your home

June 5, 2008


Carpenter bees are more active right now than at any other time of the year because they are in the peak of mating season.

You can distinguish carpenter bees from bumblebees in a couple of different ways. First, carpenter bees have hairless, shiny, black abdomens, while bumblebees have hairy abdomens that almost always have some yellow patches on them. Second, bumblebees tend to nest in the ground, while carpenter bees like to nest in wood. Last, carpenter bees are solitary, so you will rarely see them together.

Like many of our callers, there is a carpenter bee nest at my house. I see them every year in the spring, but by the time I get motivated to do anything about it, they disappear.

I finally decided to get on the ladder and survey the damage. There is minimal damage right now, so I am going to treat the holes, caulk them, and wait to see if adults emerge next year.

Here is what you need to know if you suspect carpenter bees:

¢ Damage to structures is often cosmetic. However, they can cause serious structural damage when multiple generations colonize in the same piece of wood.

¢ Males do not have stingers.

¢ Females can sting, but typically will not do so unless they are physically handled.

¢ The bees will seem to disappear later this month, but are still present. Female carpenter bees lay eggs and feed bee larvae until August or September.

¢ Carpenter bees prefer bare, unpainted or damaged softwoods.

To control carpenter bees, you must find the entry way. Holes are little more than the diameter of a pencil and often high on the structure in a protected location.

Remove infested wood and replace with pressure-treated wood if possible. Paint the new wood and maintain a good coat of paint in the future to deter new infestations.

If damage is light, you can treat the entryway and nest with an insecticide such as carbaryl (Sevin), permethrin or cyfluthrin. If the nest is not treated, adults will likely emerge next spring.

For safety, any work around the nest should be done on cool nights when the bees are less active.

Remember to read and follow all label instructions when applying any pesticide. The product must have control of carpenter bees and the structure you wish to apply it to listed on the label.

After treating the nest and entryway, fill the holes and paint over them. Wood stains do not deter the bees.

Jennifer Smith is the Douglas County Extension AgentHorticulture for K-State Research &amp; Extension. She can be reached at 843-7058 or <a href=""></a>.


Tara Painter 9 years, 3 months ago

It's weird this is posted because I just had to deal with one a couple of days ago, and I've never had to deal with them before and there quick too. In a three days period they make a good size hole the size of a quarter.

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