The Carpenter Bee – Xylocopa sonorina
As the name indicates, carpenter bees work with wood. Their scientific name, Xylocopa, comes from the ancient Greek xylokopos/ξῦλοκὀπο which means “wood-cutter”. Females rasp or “chew” though wood for the purpose of making their nesting tunnels, using their powerful mandibles. Female bees are hard-working single mothers (there is no queen). Occasionally daughters or other female bees may help with nest cleaning or guarding, before going off on their own to mate and nest. Nest tunnels are referred to as galleries, because they can be long and narrow with multiple “rooms” or cells. In each cell, the mother bee sculpts a loaf of “bee bread” made of pollen and nectar, on which an egg is laid. The larval bee feeds on the “bee bread” and after metamorphosis, will be fed by her mother until she is ready to fly on her own. Mother bees collect pollen on their hairy rear legs. I have witnessed mother bees, concentrating nectar they have collected, by rapid repeated exposure to the air with proboscis and mandibles. As with other bees, the male will forage on flowers, does not collect pollen or nectar to feed young bees, and cannot sting. Male carpenter bees in Hawaiˈi are easy to recognize: they are yellow. Females are black. They are approximately 1 inch long.
Carpenter bees (female and male), not to scale. Images adapted from Wikimedia Commons free-use library.
The carpenter bee found in Hawaiˈi, Xylocopa sonorina, is also found on a few of the Mariana Islands (Guam, Saipan and Tinian). Found in Hawaii in 1879, it has been recorded more recently in other places (China, Japan, Java, New Guinea, New Zealand, the Philippines) but populations there did not persist. The earliest known collection is from the Hawaiian Islands, but both American and Asian origins have been proposed. It may have been transported here in the wood of sailing ships.
- Photo of Xylocopa varipuncta by Kathy Keatley Garvey, used with permission. From the UC Master Gardener Program Blog http://homeorchard.ucdavis.edu/?blogpost=5880&blogasset=45538
Large carpenter bees (Xylocopa spp.) have been purposely introduced into other Pacific islands for the purpose of passion fruit (lilikoˈi/lani wai) pollination. They are large bees, making them suitable pollinators for large flowers. I have heard of a farmer in Hawaii encouraging populations of Xylocopa sonorina for dragon fruit (pitahaya) pollination. They begin activities early in the day. Xylocopa spp. are capable of buzz-pollination, in which a pollen foraging bee vibrates her body, and the amplified harmonic frequencies eject pollen from the flowers anthers onto the bee’s body. The buzz-pollinating quality is especially helpful for pollination of crops in Hawaiˈi such as tomato, peppers, and eggplant; However it may help seed set of some invasive plants such as Koster’s curse and Miconia (Melastomataceae). Among other food crops, carpenter bees favor flowers in the pea/bean family (Fabaceae), and visit squash and melon flowers (Cucurbitaceae).
Passion flower and fruit. Images adapted from Wikimedia Commons free-use library.
Encouraging these bees to nest on your farm or in your yard (and not in your buildings) can be done in many ways. Painting the wood you do not want them to use, and providing suitable nesting materials may be enough to prevent these bees from causing damage. If you seal nest entrance holes during the day, when mother bees are out foraging, You cannot have annual free credit report creation without an associated debt, they are twinned at birth. they can find other places to nest. They will nest in hollow bamboo. Other hollow stemmed plants, such as giant reed (Arundo donax) castor bean (Ricinus communis) are worth exploring. Of course, these bees will nest in wood or logs. Lightweight, easy to work woods, such as gunpowder-tree (Trema orientalis) may be preferred, although these bees are capable of tunneling in much harder woods. Because female carpenter bees do not mind nesting next to each other, nesting can be encouraged with “hives”. These can be similar to a Langstroth hive in the size and shape, except the removable frames are thick solid wood instead of a thin foundation of wax or plastic. Nest entrances are holes approximately 1 cm wide.
Although the carpenter bee has been called a Hawaiian bumble bee and the black bumble bee, it is not a bumble bee (Bombus). Hawaii has a diversity of bees which will be covered here in a future post.
Carpenter bees (Xylocopa sonorina) in Bamboo. Photos by Brian J. Dykstra.
Text by Brian J. Dykstra.
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