Carpenter Bees

Home / Pest Library / Bees / Carpenter Bees

Identification

  • Colour Yellow and shiny black
  • Size 12 to 25 mm in length
  • Also known as Xylocopa
  • Description Carpenter bees are a group of bees which, as the name suggests, tunnel and nest in wood. They represent some of the roughly 800 species of bees found in Canada. Unlike other social bee species, carpenter bees are solitary creatures that nest in excavated wood galleries instead of forming large colonies. Named for their carpenter-like abilities, the bees bore into wood to construct tunnels with individually partitioned cells for their offspring. Over time, the wood-boring activities of carpenter bees can cause major structural damage. Although they can be destructive, carpenter bees are important pollinators which rarely pose threats to the physical wellbeing of humans.
Carpenter bee close up white backround

General Facts

Carpenter bees are a group of bees which, as the name suggests, tunnel and nest in wood. They represent some of the roughly 800 species of bees found in Canada. Unlike other common bee species, carpenter bees are solitary creatures that nest in excavated wood galleries instead of forming large colonies. Named for their carpenter-like abilities, the bees bore into wood to construct tunnels with individually partitioned cells for their offspring. Over time, the wood-boring activities of carpenter bees can cause major structural damage. Although they can be destructive, carpenter bees are important pollinators which rarely pose threats to the physical wellbeing of humans.

Appearance

Large and robust, carpenter bees measure about 25 mm in length and strongly resemble bumblebees at first glance. However, the carpenter bee has a shiny black abdomen devoid of hair, which contrasts with the hairy abdomen of the bumblebee and serves as the main point of physical differentiation between the two species. The thorax of the carpenter bee features a layer of yellowish or otherwise light-coloured hair. Males have yellow markings on the head, while females do not. Conversely, female carpenter bees possess a stinger at the tip of their abdomens, while the males do not.

Habitat

Instead of establishing colonies with other members of the same species, carpenter bees construct individual nests in wood structures. They build nests in trees as well as manmade items crafted of wood. Carpenter bees prefer to nest in softwoods, such as cedar, cypress, fir, pine, coast redwood, and spruce, and prefer to attack exposed and unpainted wood. The pests tunnel into wooden structures such as decks and porches, doors, fence posts, roof eaves and shingles, lawn furniture, railings, telephone poles, and windowsills.

Diet

Unlike termites, carpenter bees do not actually eat the wood they excavate. Instead, the insects feed on the nectar and pollen of flowering plants. Carpenter bees pollinate a wider variety of plants than other bee species and also remain in pollinating mode for a longer period of time during the year. As a result, carpenter bees play an important role in the natural environment. Carpenter bees are unique among bee species because they will sometimes take nectar from a flower without pollinating the plant.

Life Cycle/Reproduction

After overwintering in protected areas, carpenter bees in Canada emerge in the spring and mate between the months of April and June. Females then begin the process of locating and excavating a nesting site. To construct the nest, the female carpenter bee penetrates about 20 cm into the wood, turns at a 90-degree angle, and excavates a gallery of 6 to 8 individual cells for her eggs. After lining each cell with a blend of nectar and pollen known as “bee bread,” the female lays an egg on top of the food source and seals it in with the pulp of chewed wood. Carpenter bee larvae hatch from the eggs and feed on the bee bread before developing into adults after about 36 days, leaving the nest in late summer, and preparing to overwinter. Adults produce one generation per year and typically die before the offspring reach maturity.

Problems Caused by Carpenter Bees

The manner in which carpenter bees construct their nests can cause minor to severe property damage. When a single carpenter bee bores into a wood structure to build a nest, the damage is typically minor and limited to the cosmetic issues created by the presence of the entrance hole. However, when left untreated, future generations of carpenter bees often reuse the same nests by simply expanding the network of tunnels and constructing new cells for eggs. Over time, the continued expansion of the nest may cause severe structural damage. In addition to damaging property, carpenter bees annoy and alarm homeowners. Male bees often defend the nest by flying aggressively at intruders. While the females can sting, they rarely do.

Carpenter Bee Stings

Carpenter bees are not normally aggressive and are instead surprisingly docile. Although female carpenter bees have the ability to sting, the insects must feel seriously provoked or threatened before they attack. Conversely, male carpenter bees do not have stingers and hence will not sting. However, they will exhibit aggressive behaviour such as hovering and buzzing loudly to ward off humans during mating season.

Symptoms

Physiological reactions to carpenter bee stings depend on the person and the incident. Severity of reactions ranges from localized pain, redness, and swelling, to anaphylaxis. Symptoms of anaphylaxis may include nausea, vomiting, wheezing, confusion, reduced blood pressure, and unconsciousness. Treatment depends on how the victim reacts to the bee sting. It is always advisable to consult a healthcare professional in incidences of severe reaction to carpenter bee stings, especially when it results in anaphylactic shock.

Prevention

The best way to avoid carpenter bee stings is to remain calm in the presence of the insects and stay away from nests. Fragrances may irritate carpenter bees, so avoid wearing perfumes or colognes while spending prolonged periods of time outdoors. Certain bright colours are known to attract the attention of bees, which increases the risk of being stung. As a result, wearing darker colours may also help to prevent stings. However, there is no way to safeguard against bee stings completely.

Detection/Signs of Infestation

To detect a carpenter bee infestation, look for the telltale entrance holes drilled into wood where the insects typically prefer to nest. Entrance holes are perfectly round and roughly 15 mm in diameter. The presence of males hovering around a wood structure is another sign of a carpenter bee infestation. Male carpenter bees are known to guard the nest and aggressively ward off intruders.

Prevention Tips

Because carpenter bees prefer exposed and unpainted wood, painting or applying varnish to wood structures can help deter the pests from settling. Wood stains, however, fail to act as an effective deterrent. Homeowners and residents should also remain on the lookout for any signs of carpenter bees and contact a pest control professional in the event that an infestation occurs. Professional pest control specialists can handle carpenter bees safely and properly, in addition to providing further information on how to prevent future problems.

Carpenter Bee Traps, Repellents, and Sprays

Carpenter bees are known for nesting in untreated wood and can damage furniture, decks, alcoves, and other sites constructed with exposed wood. Although various traps, repellents, and sprays are available to help control carpenter bees, the effectiveness of such products remains inconsistent at best. For instance, while spraying may turn out to be a useful albeit time-sensitive option, treating wood surfaces with liquid sprays requires the bees to come directly in contact with the spray, or if liquid residual spray is used, the carpenter bees must land directly on the treated areas in order for it to work effectively.

Proper Treatment

For severe carpenter bee infestations, consult a pest control professional. A professional pest control specialist is knowledgeable, certified, and adheres to proper safety practices. Furthermore, due to lack of experience and knowledge, untrained individuals who attempt to use store-bought aerosols, fumigants, or other pesticides risk misusing the products. Proper and effective management of carpenter bees involves continually treating, protecting, and searching for areas of infestation. Pest management professionals exhibit the knowledge and wherewithal to find and eliminate carpenter bees while safeguarding homes from repeat intrusions.

How We Get Rid of Carpenter Bees

Identification and Biology:

  • Searching for favorable nesting sites and mates, large, black bees will hover around structures in the late spring and summer months.
  • These carpenter bees are about an inch long with sleek, shiny black abdomens. They are best identified by their black and yellow colour.
  • Though they are harmless and lack stingers, male carpenter bees are very aggressive and will fly up to people who are near their nests. Female carpenter bees are equipped with stingers, but only sting when threatened.
  • Adults overwinter in nests and will emerge in the spring.
  • Once mating is complete, females will excavate tunnels in wood to lay their eggs in smaller cells.
  • The entrance hole and tunnels within nesting sites are round and approximately a half inch in diameter. People are alerted to the presence of these nests by piles of sawdust beneath the hole.

Inspection & Prevention

  • Look in areas such as fascia board, out buildings, decks, benches, soffits, eaves, etc.
  • Focus on undersides of exposed wood. They excavate in areas protected from the weather.
  • Carpenter bees infest plain, painted, stained & treated wood. Redwood is their favorite.
  • Sometimes the carpenter bee will attack exposed wood inside garages, particularly if a door is often open or some other access to the outside is readily available.
  • Keeping wood protected by painting or staining can help deter carpenter bees.
  • Sealing rake board makes it inaccessible to bees and other insect pests.

 

Why do I have carpenter bees?

Instead of establishing colonies with other members of the same species, carpenter bees construct individual nests in wood structures. They build nests in trees as well as man made items crafted of wood. Carpenter bees prefer to nest in softwoods, such as cedar, cypress, fir, pine, coast redwood, and spruce, and prefer to attack exposed, weathered and unpainted wood. The pests tunnel into wooden structures such as decks and porches, doors, fence posts, roof eaves and shingles, lawn furniture, railings, telephone poles, and windowsills.

How worried should I be about carpenter bees?

The manner in which carpenter bees construct their nests can cause minor to severe property damage. When a single carpenter bee bores into a wood structure to build a nest, the damage is typically minor and limited to the cosmetic damage created by the presence of the entrance holes. However, when left untreated, future generations of carpenter bees often reuse the same nests by simply expanding the network of tunnels and constructing new cells for eggs. Over time, the continued expansion of the nest may cause severe structural damage. In addition to damaging property, carpenter bees annoy and alarm homeowners. Male bees often defend the nest by flying aggressively at intruders. Females can sting, though they rarely do.

How can I prevent carpenter bees invading?

Because carpenter bees prefer exposed and unpainted wood, painting or applying varnish to wood structures can help deter the pests from boring. Wood stains, however, fail to act as an effective deterrent. Homeowners and residents should also remain on the lookout for any signs of carpenter bees and contact a pest control professional in the event that an infestation occurs. Professional pest control specialists can manage and control carpenter bees safely and properly, in addition to providing information on how to prevent future problems.

Other pests related to Carpenter Bees

Remove pests from your home, and stop them from coming back

We work hard to listen, understand and assess your unique situation. Request a free, no-obligation estimate today for a customized pest program that fits your needs.

Request a Free Home Estimate
Request a Free Business Consultation

Residential Services

Protect your home from unwanted pests with customized pest control treatment

Residential Services
Commercial Services

100% Satisfaction or Money Back Guarantee

Resolving your pest problem is our #1 priority. If re-treatment is required, we'll provide immediate services at no extra cost. If your expectations are not met, we guarantee a full refund of your service payment.

Remove pests from your home, and stop them from coming back

We work hard to listen, understand and assess your unique situation. Request a free, no-obligation estimate today for a customized pest program that fits your needs.

Request a Free Home Estimate
Request a Free Business Consultation