Carpenter bees are active now | Gardening
I began seeing carpenter bees hovering around the eaves of my house during mid-February this year. Carpenter bees are large, black-and-yellow bees often seen flying near homes, wooden fences or decks on warm days.
They may be mistaken for bumblebees, but differ in that they have a black, shiny abdomen in contrast to the yellow abdomen of the bumblebee.
Richard Sprenkel, retired UF/IFAS entomologist, shares information about this wood-boring bee in today’s article.
Carpenter bees spend the winter as adults within their old nest tunnels. After emerging in spring, adults mate, and females begin excavating a gallery with their mandibles (mouthparts) at the rate of 1 inch in six days.
The gallery has a clean-cut, round entrance hole about ½-inch in diameter. The gallery continues inward for 1 to 2 inches, and then turns at a 90-degree angle running in the same direction as the wood grain for 4 to 6 inches.
Damage from a pair of bees is slight, but if the gallery is used over several years, damage can be extensive. Once a gallery is completed, the female begins to provision a brood cell with a mixture of pollen and regurgitated nectar.
After laying an egg on top of this mass, the female closes the cell with chewed wood pulp. Each female may have six to eight sealed brood cells in a linear row in one gallery as she backs outward.
Larvae develop on the pollen/nectar food. The life cycle is completed in 30 to 40 days. Newly developed adults emerge by chewing through the cell partitions. They collect and store pollen in existing galleries, which they use for winter hibernation. There is one generation per year.
Males do not drill tunnels, but are territorial and harass other bees and people who come near their protected areas. Males do not sting, and can be distinguished from females by a whitish spot on the front of their face. Females are capable of stinging, but rarely do so unless they are highly agitated or confined in your hand.
Carpenter bees prefer wood that is bare, weathered and unpainted. The best way to deter the bees is to paint all exposed wood surfaces, especially those that have a history of being attacked. Wood stains and preservatives are less reliable than painting.
Preventive sprays applied to wood surfaces are effective only for a short period, and would have to be repeated about every two to three weeks. However, once nesting activity has begun, treating the entrance holes with an insecticidal spray or dust may substantially reduce damage. Products containing carbaryl (Sevin), cyfluthrin or resmethrin are suitable.
This article originally appeared on The Gainesville Sun: Carpenter bees are active now | Gardening
