han the females, which relates to their mating behavior. Male bees are often seen hovering near nests, and will approach nearby animals. However, males are harmless since they do not have a stinger. Female carpenter bees are capable of stinging, but they are docile and rarely sting unless caught in the hand or otherwise directly provoked.
Many Old World carpenter bees have a special pouch-like structure on the inside of their thorax called the acarinarium where certain species of mites (Dinogamasus spp.) reside. The exact nature of the relationship is not fully understood, though in other bees that carry mites where the mites are beneficial, feeding either on fungi in the nest, or on other, harmful mites.
Carpenter bees are traditionally considered solitary bees, though some species have simple social nests in which mothers and daughters may cohabit. However, even solitary species tend to be gregarious. There are two very different mating systems that appear to be common in carpenter bees, and often this can be determined simply by examining specimens of the males of any given species. Species in which the males have large eyes are characterized by a mating system where the males either search for females by patrolling, or by hovering and waiting for passing females, whom they then pursue. In the other type of mating system, the males often have very small heads, but there is a large, hypertrophied glandular reservoir in the mesosoma, which releases pheromones into the airstream behind the male while it flies or hovers. The pheromone advertises the presence of the male to females.[
These bees come in a variety of sizes although most are slightly larger than a honey bee. One of the most common species is the valley carpenter bee that is characterized by solid black females and golden males. They are as large as or larger than bumblebees.
Female and Male Valley Carpenter Bees.
As previous indicated these bees nest in wood. Their colonies consist of a series of tunnel-shaped burrows. As do other bees, carpenter bees collect pollen to feed to their young. Once collected, the pollen is formed into a ball about the size of a small marble. A single egg is then deposited on each ball, which subsequently is compartmentalized within the burrows (Figure 40). Their life cycle is completed in a few months as the larvae develop on the pollen balls.
A Tunnel of a Carpenter Bee with Developing Larva and Pupa. Image Courtesy Univar Corporation.
Carpenter bees are not true social insects as there is no division of labor, but many bees may occupy the same nesting burrow. The burrows typically are used year after year and can become rather extensive. Even though these are wood infesting insects, rarely do they do any significant damage to homes.
Occasionally they can be bothersome to the homeowner because the males are especially aggressive and will fly up to and buzz in a person’s face; however, they are totally harmless, as male Hymenoptera do not have stingers. The sting of the female is quite painful, but she is much less aggressive.
In the telephone industry these bees are referred to as pole bees because they frequently nests in telephone poles. Even though they typically do not sting, they buzz linemen and in some cases this has resulted in injuries as a result of the workers’ attempts to avoid their harassment. I am aware of more than one case where linemen have fallen from poles due to “bee attack”.
Bumble Bees. A bumblebee (or bumble bee) is any member of the bee genus Bombus, in the family Apidae. There are over 250 known species, existing primarily in the Northern Hemisphere although they are common in New Zealand and Tasmania.
Bumblebees are social insects that are characterized by black and yellow body hairs, often in bands. However, some species have orange or red on their bodies, or may be entirely black (Figure 41). Another obvious (but not unique) characteristic is the soft nature of the hair (long, branched setae), called pile, that covers their entire body, making them appear and feel fuzzy. They are best distinguished f