Solitary Bees and Wasps: An Introduction for Amateur Naturalists
The Other Bees
Large Carpenter Bee
(Xylocopa virginica)
Large blue-black bee which looks like a bumblebee, but closer examination will reveal that the abdomen is bare (whereas bumblebees have hairy abdomens). Slow, somewhat erratic fliers. Overwinter as adults and emerge in spring.
Habitat: Fields, woodland edge, gardens.
Length: 25 mm
Adults: May - October
Their common names reflect their nesting behaviour: digger bees, mason and plasterer bees, leafcutter bees, carder and carpenter bees.
Bees are remarkably diverse animals; some are only an eighth of an inch long, most much bigger, some over an inch in length. All built on the same robust body plan, bees are substantial insects. There are brilliantly green and blue iridescent bees. Others are glossy red browns and blacks. They may be striped in white, yellow, orange and even red. All the females have spectacular engineering skills, building their nests from a huge range of materials. Their common names reflect their nesting behavior: digger bees, mason and plasterer bees, leafcutter bees, carder and carpenter bees.
Most bees, unlike the social honeybee, are solitary but some are communal and many like the bumblebees and many of the sweat bees have complex social arrangements. In fact, you can argue that bumblebees are the most behaviorally sophisticated insects in the world. Because all bees provision their nests with pollen and nectar, shaping a little pollen ball for each developing larva, they are relatively easy to find at flowers. To provision a single cell may require upward of fifteen trips. Their nests, often hidden or cryptic, are not as easy to find, but all the coming and going helps. They are a fascinating focal point when you do take the trouble to track them down. The bees and their nests stuffed with pollen, nectar and growing larva are constantly under threat from a whole range of predators and parasites: hovering bomber flies, brightly colored parasitic cuckoo bees, velvet ants, sculpted iridescent chrysid wasps and the dreaded bee wolves. Many of these are nearly as interesting as the bees themselves.
There is no denying that as a whole they are a taxonomically difficult group and identifying most to species is work for the expert. The exception is the bumblebees, perhaps the most interesting of the lot. They can pretty easily be sorted to species based on color patterns along. However, most bees are pretty easy to sort to family and genera based on their overall appearance and behaviors. It’s often their nesting behavior that gives them away. A bee carving neat little circles out of a leaf is, not surprisingly, a leaf cutter. One scraping up mud at the edge of a puddle is a plaster, etc. So I don’t think it would be too difficult to develop a basic key and provide enough descriptive biology to allow even a casual naturalist to sort out most bees just based on careful observations. There is no need for pins, killing jars, microscopes and the other traditional paraphernalia of bug collecting. There is a whole world of complex biology and behavior to watch, even some pretty advanced social behaviors to investigate and discover right in backyards and gardens, small urban parks and scrubby waste areas. I once spent months studying a large, diverse and very active community of ground nesting bees and wasps in the bare hard-packed dirt at the back of a used car lot. I knew somebody who did all of their doctoral research on a colony of sweat bees in the lawn alongside his suburban driveway. I did all my research in the remnants of an old sandpit behind the family home. The bees aren’t all that hard to find. Some are among the first to fly in the spring, there are a succession of species and broods all year, and the robust bumblebees often fly past the first fall frosts. There is always a lot going on.
There’s so much you can do simply by watching. You can get remarkably close to any bee when it’s busy with flower or nest or use a hand lens or close focusing mono or binoculars.
There’s so much you can do simply by watching. You can get remarkably close to any bee when it’s busy with flower or nest or use a hand lens or close focusing mono or binoculars. (Although all female bees sting, none of the native bees are at all aggressive save a few species of bumble bees. None of these bees will sting unless you actually try and handle them—never recommended—or in the case of bumblebees, directly threaten their nest, ie: try to dig it up. None of the native bees pack the wallop of a honeybee sting.) Even watching a bee load up with pollen at a flower will often identify it to family. The different types of bee have the hairs that carry the pollen in different locations on the body.
Hunting Wasps
Like the bees, there are hundreds of mostly solitary wasp species in most places. They are overlooked, but of a good size, handsome and brightly colored with similarly complicated nesting and provisioning behaviors. I think many of the wasps are sleeker, more elegantly and elaborately sculpted than the bees. As with bees, the one or two social species (the pesky yellow jackets and hornets) dominate the most people’s concept of wasp, if indeed they even differentiate bee and wasp. There’s so much more. Unlike the bees, these wasps hunt and provision their nests with other insects. Each type of wasp seeks a certain prey—spiders, grasshoppers, bees, flies—and you can pretty readily identify many by general appearance and what they’re hunting or dragging into the nest. Although most nest in the ground, like the bees, many nest in hollow twigs or construct mud nests. A large, stout, black and yellow wasp nesting in hard dry ground and provisioning with bees (!) can only be a Philanthus. A thread-waisted black and red wasp hunting caterpillars can only be an Ammophila, the shiny blue/black wasps collecting mud at a puddle’s edge are mud daubers probably nesting under a nearby eave.
This incessant hunting puts a huge dent in many insect species considered to be pests. One afternoon over a few hours, I watched a small colony of Sphex in the sandy soil on the side of a septic hill haul back probably more than a hundred absurdly large grasshoppers (some so big the wasps couldn’t fly and instead, dragged their prey overland). This voraciousness often earns them a place in the gardeners’ encyclopedia under “Beneficial Insects” but they’re worthwhile for more than their appetites.
The nesting behavior of some wasps may be even more elaborate than that of bees. Many wasps go to great pains to camouflage the nest entrance; some of the more common ground nesting wasps even use ‘tools’, tamping down the loose soil near the entrance by pounding the earth with pebbles held in their jaws. Like the bees, a few species have developed primitive social habits, but unlike the bumblebees in their underground nests, the common paper wasp’s simple social behavior—posturing, displaying, sibling rivalry—all the bickering and coming and going is easily seen and heard on the open combs tucked up under a porch or eave. As mentioned with the bees, there’s some terrific classic natural history to draw upon and much captivating modern research. Again, these elaborate hunting and nesting behaviors combined with the general appearance often allow for a relatively simple identification, at least to broad category.
