 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 from similarly large, fuzzy bees by the form of the female hind leg, which is modified to form a shiny concave surface that is bare, but surrounded by a fringe of hairs used to transport pollen (in similar bees, the hind leg is completely hairy, and pollen grains are wedged into the hairs for transport). Like their relatives the honey bees, bumblebees feed on nectar and gather pollen to feed their young. One characteristic of bees in general is that the body hairs are profusely branched making them more efficient in trapping pollen. Their mouthparts consist of a tube-like proboscis for siphoning the nectar from pants. It is coiled up when not in use.
A Bumbles Bee with Uncoiled Proboscis in Preparation for Removal of Nectar. Image Courtesy FFubs. Right. Bumblebee with Pollen Trapped on Hairs. Image Courtesy of Jesse Hickman
The brightly-colored pile of the bumble bee is a form of aposematic signal, meaning the bright coloration is a sign that I am bad-don’t mess with me (Figure 42). Depending on the species these colors can range from entirely black, to bright yellow, red, orange, white, and pink. Thick pile can also act as insulation to keep the bee warm in cold weather. Further, when flying a bee builds up an electrostatic charge, and as flowers are usually well grounded, pollen is attracted to the bee's pile when it lands. When a pollen covered bee enters a flower, the charged pollen is preferentially attracted to the stigma (female part of plant-thus fertilization occurs) because it is better grounded than the other parts of the flower.
Brightly Colored Bumble Bee. Image Courtesy Christian Sand.
Bumblebees are typically found in higher latitudes and or high altitudes; though exceptions exist (there are a few lowland tropical species). A few species range into very cold climates where other bees might not be found; Bombus. polaris can be found in northern Ellesmere Island (west of Greenland)—the northern most occurrence of any true social insect. One reason for this is that bumblebees can regulate their body te