26 Jul 2019

Carpenter Bees



Last weekend I had an unwelcome visitor. A carpenter bee decided that my deck would be a good place to raise a family. I disagreed. If you don’t know about these amazing insects, here goes:

 Carpenter bees are quite different from honey bees. Carpenters don't make honey and they don't live in communal hives. They seldom sting - only the female (queen) is capable of stinging. The males will buzz around you and try to intimidate you, but are actually harmless.

A carpenter bee, without a tool belt.
Photo: Daniel Schwen.

How do you recognize a carpenter bee? If you’re lucky you may also be able to see one wearing a tiny tool belt, with saw, hammer, pliers etc. Otherwise they look a lot like bumble bees, but they have a black shiny bum, instead of a furry one. But the dead giveaway is that they drill beautifully round ½” holes in any piece of wood that they fancy for a nursery. 

This carpenter bee chose a tree.
Photo: ZooFari.
 Here’s a picture of the hole that “my” carpenter bee drilled under the railing of my deck. 

 This is actually the second hole. The light-coloured stuff is Play-doh which I used to fill in the first hole, in a vain attempt to stop her. I chased her off the second time and sprayed the hole with insecticide which evidently she didn’t like.  


Carpenter bees are good pollinators and we need them, so perhaps I should have been more generous. But I selfishly want to keep my deck, and carpenter bees don’t really care. If I had let this queen carpenter alone, she would have drilled out a long (about 6 inches) passage at right angles to the initial hole. She would have alternated filling the chambers of the passage with pollen and eggs. The eggs would have hatched and larvae would have fed on the pollen. Then the larvae would have become pupae which would have become adult carpenter bees, The process would have taken seven weeks to produce a bunch more carpenter bees to continue carving up my deck. 




You can see why I didn’t want my deck to become a carpenter bee nursery.



1 comment:

Paula Johanson said...

Simon, you've identified the pair of issues brought up at every nature talk that a scientist or naturalist gives for the public. At a talk on river otters, I heard a neighbour ask the scientist the two questions that are always asked. The first question is, "How can I make my yard a good environment for otters to visit?" The second one is, "How can I keep otters from living under my porch and pooping here?" Like the issues you faced with pollinators drilling into your deck, homeowners have to find a way somehow.