Monday, June 17, 2013

Pollinator Week: Carpenter Bees

Pollinators - Carpenter and honey bees - on Anise Hyssop.
reprinted with permission from I've Got Company!

Here in Cobb County, any home with wood parts exposed to the outside world will at some point have those wood parts riddled with holes by carpenter bees. It's part of what carpenter bees do, and, as a result, it can be hard to think of those big, shiny, native bees as anything but pests.

They do, though, have some redeeming qualities. One of those is that they are pollinators of some flowers.

The U.S. Forest Service article Carpenter Bees, by Steve Buchman,  notes that some of our garden vegetable crops are effectively pollinated by carpenter bees:
"In our vegetable and flower gardens, carpenter bees are generalists and may be found foraging on a number of different species. They, like bumblebees are early morning foragers. Carpenter bees land on flower blossoms they become living tuning forks. Using their powerful thoracic muscles carpenter bees sonicate the dry pollen grains out of the flower’s anthers. This type of pollen gathering is called “buzz pollination.” Carpenter bees are excellent pollinators of eggplant, tomato and other vegetables and flowers."
Cornell University notes in its publication Wild Pollinators of Eastern Apple Orchards that carpenter bees also are effective pollinators for apples.

According to UGA's publication "Pollination: Other Pollinating Bees,"
"[Carpenter bees] are effective pollinators of passionfruit. In Georgia, they visit blackberry, canola, corn, pepper, and pole bean, but their value on these crops is uncertain. Carpenter bees are notorious for "robbing" flowers by cutting slits in the side of the flower to reach nectar without even touching the pollinating parts."
Even though they might not be primary pollinators for many plants, carpenter bees' role in pollination of passion flower, which is a host plant to several beautiful butterflies, might be enough to bring them a little sympathy from homeowners. However, the damage caused by carpenter bees in making their nesting holes can be extensive.

In order to have our pollinators and undamaged homes, too, it can be helpful to follow prevention guidelines such as those in Alabama Cooperative Extension's publication "Carpenter Bees, Biology and Management," and consider setting out wood nesting blocks for use by the bees.