Question: These black bees are killing my Ligustrum bush!!! I hear buzzing in the stems at night. The stems or limbs are dead. What are these bees and how do I eliminate them?

Answer: The bees are not killing your plant---they are just setting up housekeeping in dead branches. Carpenter bees are large (1 inch) yellow and black bees which become active in early spring. They resemble bumble bees but do not live in colonies, have fewer hairs, a shiny black abdomen and no pollen sacs on the hind legs. Although it is rare to be stung by one, their sheer size is scary and people generally stay clear of them.

The female will go in and out of the nest so patience will show where the entrance is. Killing individual bees with a liquid insecticide will not destroy the bee's young. The nest must be treated!

Biology
Carpenter bees get their name from their ability to drill through wood and nest in it. Their drilling will create a near perfect hole approximately ½ inch in diameter. This hole is usually located on the underside of any wood surface. Although the hole appears to be only an inch or two deep, it doesn't end there. The female will turn 90 degrees and bore a channel from 6 inches to as long as 4 feet. This channel serves as a main corridor from which she will drill small chambers a few inches deep. These chambers become egg holders. She will deposit an egg, bring in some food, and then seal it off to ensure the egg's development.

The male spends most of his time flying around the nest playing guard. This is ironic as nature has left him ill prepared; he has no stinger! Only the female can sting. Simply killing the male will not solve your problem. To eliminate carpenter bees, you must treat the nest!

Control
To treat the carpenter bee holes, dust the entrance hole with Orthene. As the female enters the hole she will drag the dust into the nest and kill all the larvae.