Xylocopa virginica Photo Fiona Sunquist ©
If you have ever noticed a large black and yellow bee hovering at head height around a wooden building, it is almost certainly a carpenter bee. Carpenter bees look like bumble bees but have a shiny black abdomen.
Carpenter bees are named for their habit of excavating holes in deck railings, wooden siding, steps and other horizontal pieces of wood. The bee uses its jaws to chew through the wood, tunneling at the rate of an inch a week -- each nest tunnel is usually about six inches long. The female carpenter bee lays an egg at the end of the tunnel, leaves a pollen ball for the grub to eat, then seals the nest with a wall of chewed wood. She lays as many as seven eggs in each tunnel.
Carpenter bees do not sting, and rarely drill enough holes to cause much damage. Painting or varnishing the wood will discourage them. Larger problems can arise when woodpeckers locate a carpenter bee colony and drill out large swaths of wood in search of the grubs.
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