Steve Bender

OK, that title is what we literati called "hyperbole," but it did get your attention. And there's another thing grabbing your attention right now if you walk outside near any wood -- big, black bees hovering in the air like little helicopters. What are they? Whacked-out bumble bees who have been drinking at Starbucks?

 

Nope. They're not bumble bees, but bees that look very similar -- carpenter bees. Don't be afraid for yourself -- the males don't have stingers and the females rarely sting. Be afraid for your wood siding, deck, or porch.

 

While both bees pollinate flowers, here are some importance differences between them that can help you differentiate them.

1. Carpenter bees nest in wood and can cause serious structural damage if there are enough of them (see photo below). They don't eat wood like termites, though. Bumble bees nest in the ground.

2. While both bees are mild-mannered and rarely sting unless provoked, carpenter bees hardly ever sting because it's the stingerless males you mostly see.

3. Carpenter bees have a light-yellowish band behind the head and a shiny black abdomen. Bumble bees have a whitish band and a dull black abdomen.

4. Bumble bees mainly concern themselves with flowers. Those hovering bees you see are male carpenter bees defending their territories against other carpenter bees. They'll try to chase off anything that approaches the nest, including you, but it's all a bluff, because they can't sting.

So what's the problem with carpenter bees? Here's a hole one of them carved into my deck. It's about 3/8-inches wide and almost perfectly round.

 

Big deal, you say? What if I told you the wood was pressure-treated pine that's so hard it's difficult to drive a nail into? This bee chewed through it like a brownie.

 

I thought a primary purpose of pressure-treated wood was to prevent insect damage. Unfortunately, the Feds decided to take out the arsenic that was part of the chemical treatment, saying it was a health hazard (yeah, mainly to termites and carpenter bees). My old deck stood for 10 years without one iota of insect damage. This new PT wood gets riddled right away. (Consider this when putting new PT wood into the ground.)

What can you do to protect wood against carpenter bees? One thing is paint it. For some reason, carpenter bees prefer unpainted weathered wood to painted wood. Second, if you are so inclined, spray the unpainted wood according to label directions in spring with an insecticide containing cyfluthrin, such as Bayer Advanced Carpenter Ant & Termite Killer (it kills carpenter bees too). Pay special attention to the under surfaces of decks, porches, and railings, as carpenter bees like entrances to their nests to be hidden. Also spray all old carpenter bees holes, as new bees will move in if you don't.

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