The Great Black Wasp

This is a photo of a great black wasp, Sphex pennsylvanicus, solarized of course, taken at the UIC greenhouse the other Friday. Incredible animals.

Halictids

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These are two halictid bees from Oak Park, IL, taken by my former field assistant, Marcus Thomasson. The one on the top is Laisoglossum sp., a halictid bee which builds nests in underground tunnels, dug in sand. Most species are social, though some are solitary. Females work together to build a nest in spring, and one of them bullies the other into submission. Their offspring are born, destined to be workers, of sorts. Twenty or thirty bees is large for a Laisoglossum colony. The one on the bottom is Sphecodes sp. It is a parasite, laying its eggs in Laisoglossum cells (I do not know how host specific they are, presumably, Evylaeus, Halictus confusus, or anything similar will do). The females emerge in the spring, with the would-be queens of Laisoglossum, and seek unwary hosts.

Apoidea

The day before yesterday, I identified a Halictus parallelus from WI. This is a social bee, though it lives in small colonies, not the metropolis hives of Apis, the honeybee. A lifelong beekeeper tells me that the reason Apis is getting so many diseases is that it never evolved to stay in the same place for year after year. Apis swarms at the drop of a feather in summer, and yesterday, Mr. Beekeeper was pulling a swarm off the cyclone fence. It escaped, a rare thing nowadays, feral bee colonies. My Halictus queen never got to found one. Sandy country out there in WI where I caught her, and hopefully her distant realatives are doing well. Six or eight workers, maybe more by now. It will all be over in August or Sept, the whole set of workers having spent their lives to produce a dozen or more queens and a similar number of males. Sand, not wax. Tunnels, not hives.
In my garden, Agapostemon viriscens, on my sunflower, and Megachile georgica. The first a beautiful green halictid bee, like halictus, but only quasisocial. They share nests as an incidental effect of their construction activities, and tolerate each other, but do not truly cooperate. I see big females and smaller ones though, a big one was foraging earlier this year, and I am beginning to conclude that this species leans toward eusociality. I read that eusociality, queens and workers, evolved over and over, and has been lost as many times, in that family, the halictids. Tattoo on my arm reads...I serve no queen. Entomology joke. Speaking of kinky, Megachile georgica practices bondage. The males have enlarged tibia to block the female's vision during mating. Another Megachile, Ashmeidella, very tiny, ID'd my first one only recently. Also, a strange parasite, probly torymid, from a trap nest I set out behind the greehouse. How the thing found a host, in Chicago, amid such uncertain surroundings, I cannot comprehend.

Summer Bee Update

Weird year for bees. Wet weather. Favors some and hinders others in a way I do not yet understand. Bees are complex in their population biology-always going extinct in one place and growing to abundance in another. There is a study of bees in Carlinville IL, the most famous bee study ever, in the late nineteenth century, by a man named Carson. There is a return study that concludes that, despite changes, most of the same bees are still there. In my yard, everything has speeded up to a ridiculous degree. Male Megachile georgica swarm and lek about ornamental sunflowers. Agapostemon viriscens, not early at all, but back from a long hiatus, forages there.

Bees

What, Exactly, is a Bee?

In essence, a bee is a glamorous wasp. This is not to say that there is anything unglamorous about wasps, but most people draw a sharp distinction between those seemingly friendly, apparently joyous little creatures that go about visiting hollyhocks on summer days, and those ferocious and sometimes threatening denizens of the soda can, the eaves of the house, the sand dunes back behind the swimming beach. Bees are a particular lineage of wasps, composed of several distinctive families, all sharing a common ancestor. This branch on the tree of life fits within a larger bush, a lineage called the superfamily Apoidea. The Apoidea includes predatory wasps as well as bees, and its members share so many distinctive characteristics as to indicate that this bush is simply one branch within a much larger bush called the suborder Apocrita, which, in turn, fits within the insect order hymenoptera, et cetera. The branch that includes bees is sometimes called the Anthophila, latin for “flower lover.” As a branch, the Anthophila have done very well for themselves. The nine families of bees include approximately 30,000 species, outnumbering their various distant relatives that still carry on a predatory lifestyle.

These predators, called Sphecid wasps, include about 8000 species worldwide. They are still out there, making a living much way the Mesozoic ancestors of the bees probably did. Sphecids are ferocious creatures, hunting spiders, grasshoppers, and other unfortunate arthropods. They are very diverse their methods of doing this, but a clear pattern of simple to complex in their evolution. The rapacious habits of sphecid wasps are all variations on a single theme. They go out and find a victim. They sting it into a state of paralysis. They drag it home to a nest. They lay an egg on it. The larva hatches, devours the victims, and reaches adulthood. This new adult goes out to kill and kill again, just like its mother, or to mate and die, just like its father. The nest may either be previously constructed, constructed on the spot, or the result of an opportunistic decision to use whatever crevice is nearby when the mother wasp dispatches her unfortunate victim. This nest may be excavated in the soil, chewed into a rotting log, carefully crafted out of mud, resin, or something resembling silk. Within this nest, there are cells; particular enclosed chambers where the unfortunate victims of sphecid maternal instinct wait, in isolation, for the growing wasp larva to consume them alive. A nest may have a single cell, or many. A cell may have a single prey item, or many. These victims may all be members of the same species, or members of an assemblage of arthropods that, to the mother wasp, looked sufficiently similar to warrant killing. No matter what the contents of the call, an egg is laid within, either before or after it is stocked with tortured victims, and that egg is intended to hatch and ultimately devour the contents. Typically, the focus of sphecid hunting is very narrow. The mother wasp will focus obsessively on hunting a particular type of prey, such as spiders of the genus Neoscona. Different wasps hunt different victims, though there is a tendency for particular lineages of sphecids to focus on a particular kind of prey. Members of the family Ampulcidae, for instance, terrorize cockroaches. Members of the genus Ammophila, for instance, hunt crickets.

This hunting behavior serves one purpose, to ensure that the developing offspring of a wasp have enough to eat. Adult sphecids wasps do not actually eat the creatures they kill. Like many flies, beetles, vespid wasps, Lepidoptera, and bees also, sphecid wasps have a very distinct dietary dichotomy between adults and offspring. Adults drink nectar from flowers. Nectar is basically all sugar and no protein. Carbohydrates are an excellent source of energy. The lack of protein is nearly irrelevant, because the animal has stopped growing, and nectar is sufficient to keep the animal going as long as it hunts victims and digs nests. This nectar feeding habit might actually be even older than the prey-hunting habits of the sphecidae, an evolutionary holdover from some primitive hymenopteran ancestor that drank sap from sap flows as a supplementary energy source.

The common ancestor of the bees evolved a trait of enormous ecological significance, a trait which was to enable the diversification of bees into a tremendous number of species, and to influence the future evolution of almost every other plant and animal on land. It was right under the noses of the sphecid wasps as they drank nectar before their next foraging run-pollen. Rather than hunting unfortunate insects as prey for their offspring, they evolved the ability to gather pollen, roll it into balls, soak it with nectar, and lay an egg on this mass. Animal material took the place of plant material in the cells of these new wasps. Basically, their life cycle stayed the same, though this switch in behavior precipitated the rapid evolution of various, diverse, structures and behaviors for pollen gathering. Pollen from some plants is stickier than pollen from other plants. Some plants have pollen that is much easier to reach. Suddenly, it became relevant which particular species of flowers these proto-bees were visiting. Some lineages of bees specialized on particular flowers, others did not.

Besides being less inherently ghastly, this provisioning behavior opens up a wide range of ecological possibilities. Pollen is a high-protein food full of nutrients, and when combined with nectar from flowers, it is ideal food for developing bee larvae. Unlike, say, a particular species of arboreal katydid, pollen is very abundant in the terrestrial environment, though pollen from a particular type of flower may not be. The insects their sphecid ancestors hunted, pollen from particular flowers is seasonally superabundant, but absent for most of the year. It is quite possible that the first bees inherited the ability to be dormant for long stretches of time, only emerging during the optimal window of time, from their sphecid ancestors. Not all bees do this, however. Some are present all year long, visiting a wide variety of flowers. Most importantly, however, this new specialization on pollen feeding exerted tremendous evolutionary pressure on the flowers the bees visited. An incidental effect of pollen feeding is the transfer of pollen, something of enormous consequence to the plants visited by bees.

Not all wasps that collect pollen are called bees. This remarkable shift in behavior and ecology has evolved at least twice. A second group of wasps, this time a lineage of vespoid wasps called the masaridae, has also evolved a pollen-gathering existing. Masarids resemble bees in many respects. For reasons that are unknown, perhaps simply because they were co-opted from many ecological niches because bees got to them first, the masaridae are not particularly species rich or ecologically important. Masarids are widely distributed in the tropics, but they are nowhere as important as bees in their ecological impact.

Likewise, not all bees gather pollen. Many have switched to an existence that is essentially parasitic upon other bees. This transition has happened many times in the evolution of bees, and it seems to occur whenever there is a clear opportunity for one species of bee to enter the nests of another species, usually a close relative, and to lay its own eggs in the cells built by another species. They are not like the usual parasites, flukes, tapeworms, ticks, and such, in that they rob parental care from their host, rather than nutrients, blood, glucose. Instead, they rob their host of parental care. In doing so, these villains of the bee world joined a long list of insect lineages that parasitize the cells off bees, and the pollen-collecting bees, the wasps.

Most people have a fairly clear idea of what a bee looks like. They are fuzzy or hairy, they are about the size of a honeybee, they are black and yellow, they have two pairs of wings, and they sting. Some people go even farther and tacitly assume that the only type of bee out there is the honeybee. If they stop to think about it farther, they add bumblebees to the list. This is not so much a reflection of a vast, aesthetic void on the part of the general public, much as the author tends to view it that way, as it is a reflection of exactly how efficiently bees go about their business without any need on our part to oversee their activities.

In fact, a honeybee is on the large size, as bees go. Bees occur in a range of sizes, from tiny members of the genus, Dialictus, which could easily fit on the head of a pin (maybe with their abdomen sticking out a bit), to very large carpenter bees of the genus Xylocopa, and queen Bombus, who would not be dwarfed by a golf ball if set right next to it. They come in a variety of stunning colors. Metallic blue and metallic green are favorite color schemes in the bee catalog, as are a range of silvery whites and greys, rusty reds and oranges, and amazing jet black, with or without red or yellow markings. Many bees are hairy, many bees are not. Hairs are thermoregulatory structures to bees, as well as pollen-gathering apparatus, and different species have evolved different levels of hairiness to accomplish an optimum thermoregulatory balance. Hair can be inconvenient under the soil, and in very tiny crevices as well, so there are a great many minimally hairy bees that, to a casual observer, resemble wasps. Bees are, in fact, quite diverse in their appearance.

Not all bees are social, in fact, most bees live solitary lives. Only a small fraction of bees live in colonies, and most social species live in colonies about the size of a football team or a metal band.

Andrena imitatrix

Today is THAT day. It is the last regular day of the semester. Students are busily calculating their points. Various point totals have been tabulated. Glory, failure, triumph and defeat, I can hear it all coming to pass in the hallway outside my cave. I hide in here. If there were any use in hiding under a table, I would hide there. I ignore their knocks. There are no more points for them. They have one more chance, which is to confront the best-four-of-five dynamic inherent in the optional final.

I hate points. I hate their obsessive focus on grades. I understand it, but I hate it. Only a small fraction of them are here for their education. For the others, they have responded to the family ambition to produce a doctor, a pharmacist-something practical and reeking of status. These occupations cleverly control supply, so that given high demand, they can assure their members high salaries, days off, golf, and the luxury of never answering the phone. The students, for the most part, do not understand this. Most of them will never make the cut. My job is to perform the initial phase of weeding. Those of them that cannot learn a great deal of heavy material in a short space of time will not make it to doctorship. Instead, they will do other things with their lives, and most likely, be happier. Nobody should be a doctor unless they have a genuine desire to serve humanity...I wish I could test for that without blatantly abusing my power.

Why did we invent points? They are a cheap, stupid, means of weighting the relative value of assignments. I first encountered points at UCLA and was stupefied. Points, being arbitrary, vary from one class to the next, and are somehow non-transferable.

What do I want from them? Everything and nothing. I want the impossible-for each and every one of the 450 students in bios 101 to blister with intellectual curiosity. I would probably give them all A grades, blisters and all. I do not expect this, I understand their utilitarian perspective. It makes me wish LSD were still fashionable at universities. I see the cosmic all.

This day, every semester, I remember the opening scene to Indiana Jones and The Last Crusade, where the protagonist escapes out the window to his office, and think fondly.
Unfortunately, my office has no windows.
Soon, I will escape to an undisclosed location.

Every semester, they start as a list of names. Soon, they become points on a spreadsheet. Some of them become unique challenges; cheaters, squeaky wheels, the wonderful ones who are incredibly smart and learning a great deal-but do not do well in the class, because they overthink everything. Others quietly come and go. Every semester, one or two become friends.

The lost mariner is my friend now. She might last. I have another in the works, perhaps, and perhaps a few from the other place I teach.

The others, become a list of grades. Next semester, the process starts again.

A week ago, I corrected one of my species identifications. A species I had identified as Andrena fenningeri was actually Andrena imitatrix. This is the sort of mistake a taxonomist makes if they follow a key too precisely, and have no real fee for the various subgenera of Andrena. The latter bee is highly polymorphic, exhibiting widely different colors, textures, and, most likely, other aspects of its phenotpye, in different parts of its range. The former bee is rare, but widely-ranging. I wonder of fenningeri exists at all, actually, or is part of the variation in another polymorphic species. Labels.

Andrena imitatrix is born, after months spent under the ground, knowing precisely what it needs to locate food sources, build nests, reproduce, survive. Millions of years of coevolution with flowers, huge triumphs and tragedies as ice ages came and went. In general, Andrenas prosper in Northern latitudes, exploiting that guild of vegetation that flowers in spring before the trees leaf out. By the hundreds, Andrena species have migrated north and south as the ice ages, six of them at least, waxed and waned over the face of Eurasia. In my collection, it is a name. A record. Names.