Plant Protection - Carpenter Bee Control
Carpenter bees are prevalent throughout the United States. Although there are different species, the most common is big and resembles a bumblebee. You may find it foraging around flowers, shrubs and under the eaves of buildings. This bee is unique from most because it will bore into wood to make its home. They are a nuisance and can cause damage to any wood part of your property. They also bother homeowners by ‘attacking' them.
To keep your building free of Carpenter bees, you must know their biology and habits. Carpenter bees bore holes into wood overhangs, fence posts, and trees. They will crawl between cracks of siding and roofing. When they bore in wood, the hole they drill is about 1/2". This hole will go straight an inch or two and then turn 90 degrees. This new portion of the nest becomes an egg chamber. Eggs are laid at the end of these chambers. Food is placed alongside the egg and then sealed tight. It is common for an egg chamber to be two or more feet long. The female Carpenter bee will stand guard at the nest entry hole. She will defend the nest aggressively. Once the drilling has been completed, she will spend her days foraging for food. You may find her working Azaleas, Bradfords, Daffodils, Pansies and any plant that will provide pollen.
Carpenter bees are commonly mistaken for bumblebees. There are two differences: 1) Carpenter bees are generally larger; 2) Carpenter bees have an abdomen that is shiny, metallic and black in color. Their abdomen has no body hair. Bumblebees have yellow and black body hair on all body parts. Male bees will be hanging around these same plants hoping to find receptive females. The male bees are curious and will buzz around people. This buzzing scares people into thinking they are being ``attacked." In fact, the male bee does not have a stinger. He has a distinctive yellow face, which may be seen while he is in flight. Female bees have no interest other than collecting food. They have a stinger and their face is black.
In addition to ‘attacking' residents, Carpenter bees are a problem because they tend to return where they were born. Old nests are used year after year. If the original nest is occupied, other female bees will drill new ones. A single nest the first year will become two or three the next. Problems rapidly escalate and soon you may have hundreds of holes. When you have numerous nests, you will have numerous larva. The larva of Carpenter bees is large and noisy. They make enough noise to attract woodpeckers. Buildings that have woodpeckers damaging exposed wood are doing this to feed on some insect. This insect is most likely Carpenter bee larva.
To control Carpenter bees, you must think long term. The nuisance male bees are easy to kill with PT-515 Wasp Freeze. Unfortunately, killing the male bee will do nothing to stop the cycle. You must treat the nest with some material that will last a long period of time. If you spray liquid materials in their hole, you may kill the female. The eggs are protected, however, and six to twelve months later the larva will emerge. Since liquids are absorbed by porous wood, they will be gone when the larva hatches. This means the larva have a strong chance of survival. To insure complete control, use a dust called Drione. It has a desiccant action and when the larva emerge they will be dehydrated. It is recommended that entry holes are treated with Drione and then sealed using a special ½" cork. This will protect the dust from breakdown and enable it to kill any emerging larva in the future. You also will know which holes you have treated so new ones can be easily identified. Since the holes can penetrate several feet, you should use an applicator like the Crusader Hand Duster. This tool will help you to apply the dust with enough force to reach deep in the nest where the eggs and larva will be living.
To stop further nests from starting, you must finish all exposed wood with a protective paint. A hard finish will deter Carpenter bees. If a natural look is desired or if it will be a while before you can paint, then spray with Cypermethrin. This product is active against many pests including Carpenter bees. Mix it at the rate of 1 ounce per gallon and spray it on any wood surface where Carpenter bees may want to bore a nest. One gallon can treat up to 1000 sq./ft. Use Cypermethrin on decks, overhangs and fence posts to stop further nests from starting. This application rate works well when treating cedar homes and log cabins. These structures are particularly subject to Carpenter bees. If you want to keep these structures natural it means that you have to do more spraying to keep away Carpenter bees and other wood destroying pests. Apply the Cypermethrin once every 2-4 weeks in the spring when they are most active. Once month applications throughout the summer will probably provide protection but you may need to increase the applications to every 2-4 weeks in the fall as well. Although rain and humidity will break down the chemical, it is active enough that even trace amounts will chase these bees away. Carpenter bee awareness and control will help eliminate these ‘attacking' bees from harassing you and your family!
IMPORTANT: READ AND FOLLOW ALL LABEL DIRECTIONS –
IMPROPER USE MAY EFFECT HUMAN AND ANIMAL HEALTH
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