Article for July - August 2008
The bees of South Carolina
by David L. Green
Besides honeybees, there are an estimated 500—maybe even 700 to 800 species—of bees in South Carolina. People tend not to notice most of these species because many are tiny and live in the ground.
Blueberry bees: The huge family of huckleberries and blueberries, which serve as important food for birds and wildlife, have their own, specially adapted pollinator that looks like a miniature bumblebee, but is solitary and nests in the ground. If you see finger-sized holes in great numbers on a dirt bank, it’s likely you are looking at the nest site of the Southeastern blueberry bee. I once found a large aggregation of these nests on a pond spoil bank and began monitoring them, but the nests were utterly destroyed by kids riding four-wheelers up the bank.
Carpenter bees: The gentle giants that drill holes in wood, and are often mistaken for bumblebees, are actually carpenter bees. They are quite curious, and the males will hover in your face, checking you over. This can be a bit unnerving for folks who are not aware that male carpenter bees, like all male bees and wasps, have no stingers and cannot hurt people. Unlike the curious males, female carpenter bees are too busy gathering provisions and making their nests to bother with you. The males are territorial, driving off other males and trying to mate with any small thing that moves in their turf. I’ve had some laughs while watching drone carpenter bees try to mate with nesting wrens. The wrens would scold the errant bees, but they would just hover until the birds took off, when they would resume their hot pursuit.
Carpenter bees are valuable pollinators in South Carolina. In areas where honeybees are absent, they become the primary pollinators of open-faced flowers of many spring fruits such as peaches, apples, chickasaw plums and some wild cherries.
Lowcountry South Carolina has a treasure trove of these bees nesting in abandoned tobacco pack houses. One advantage they have over other bee species is that most of them are dormant and protected in their nests by the time cotton spraying starts.
In the Caribbean, where their value in passion fruit pollination is recognized, some growers provide softwood beams for them to nest in. In the United States they are mostly thought of as pests and an Internet search will turn up many ways to kill them.
Of the carpenter bees, two species are common in South Carolina. The huge Xylocopa virginica, or Eastern carpenter bee, bores holes in soft wood. We have some in the soffit of our house, and I welcome them. When they appear, I know it’s really spring. Some think they do tremendous damage to wooden structures, but serious damage is rare. A fifty-year-old warehouse where I work has hundreds of carpenter bees in its joists and rafters. The building has had multi-ton loads on the floor without the slightest sagging. The smaller carpenter bee, Xylocopa micans, with its glossy, iridescent black color, is one of the prettiest bees there is. It nests in twigs, so it is no bother to homeowners.
Bumblebees: These big, brawny bees are among our most valuable pollinators for large flowers. Some North American species of bumblebees are becoming rare or may even be extinct. Few species are as common as they were a generation ago. Bumblebees make a small colony of 50 to 150 bees that are at their greatest strength (and pollination value) from mid to late summer. They like to find small cavities such as mouse holes, small bird nests, hay bales or old furniture that’s tossed on a dump pile. They especially love to find fibrous material such as cotton, straw or fiberglass insulation in their nesting sites. A couple of American species will sting like fury if their nest is disturbed, but are quite laid-back in most situations.
Halictid bees: These bees appear in a wide range of sizes—some are no bigger than gnats—and colors, though many are metallic green or steel blue. They are the real workhorses when it comes to pollinating wildflowers. Some of the tiny ones seek out salt, so they will land on sweaty humans, hence the common name “sweat bees.” They can sting, if pinched, but it’s no worse than a mosquito bite.
Megachilid bees: Kids used to call them “jelly-belly” bees because of their yellow bellies. Megachilids move very fast and “doggie-paddle” through the stamens of the flowers to catch the pollen, which they pack into the yellow “scopa,” or pollen baskets on their bellies. The pollen is carried back to supply the brood nest, but some is also transferred to other flowers in the process. Megachilids are also a large group. Leafcutter bees, genus Megachile, infuriate rose growers by cutting semicircle sections of leaves, which they use like colorful wallpaper to protect the cells of their nest.
The Osmia, or orchard bees, are megachilids, but they are special in that they can easily be cultured for early spring fruit pollination. They love to nest in hollow reeds, in the cracks of tongue-and-groove lumber or in bored wood blocks, or straws people provide for them.
Andrena and Colletes bees: These bees, commonly called sand bees or cellophane bees, look like small honeybees to the novice. They are important for many spring fruits and wildflowers. Colletes bees secrete a waterproof lining for their underground nests to protect them.
Melissodes bees: These summer and fall bees are most likely to be seen on sunflowers, Coreopsis, or other composites in the aster family. Some are almost as big as bumblebees, and are usually dark in color. From above, they look like they are carrying big saddlebags because they have pollen baskets on their rear legs that really bulge out when full. They are part of the group often referred to as “digger bees” or Anthophorids. There are many species of Melissodes and they are quite hard to identify to species level.
Squash bees: One type of digger bee known as the squash bee, looks much like a worker honeybee, but is a little smaller and specializes in squash, a native plant to the Americas. The most common Genus is Peponapis. One positive way to see if you have them is to look into the flowers that have closed by afternoon. The male squash bees will be hanging out inside, awaiting the return of the females on new blossoms in the morning. The males are also easy to spot in the morning while they patrol the flowers. They are much more skittish than the females or than honeybee workers. They will drink nectar but they never bother to forage for pollen. Also they have long antennae compared with female bees, as do males of most bee species.
Some claim that squash bees could accomplish all our squash and pumpkin pollination, but I’m skeptical, as I’ve seen too many pollination failures in fields of squash, and I’ve seen large fields with abundant honeybees and a few bumblebees doing the job with nary a squash bee in sight. The squash bees I’ve seen have all been in (unsprayed) gardens or small plots, where they are quite valuable.
Dave Green was a commercial beekeeper who specialized in crop pollination service for growers of watermelons, cukes, squash, cantaloupes, strawberries, peaches and apples. He sold his business and retired a few years ago. After awhile he took up a second career as editor of a small-town weekly newspaper.
© 2008 South Carolina Wildlife Magazine, July - August 2008 - www.scwildlife.com