Diverse in size and feeding habits, bees exhibit a wide range of social structures. Most people have some elementary understanding of the complex relationships of bees in a honey-producing hive. A hive of honey bees may contain up to 40,000 bees, with the queen producing 1,000 to 2,000 eggs per day to replace worker bees lost to predators while foraging and those dying of old age. However, there are many forms of bees who exist in colonies containing a few dozen to a few hundred individuals. Bumblebee colonies typical contain around 50 to 200 bees in August or early September when their population is at its highest.
Bumblebees are among the bulkiest bees in America. Important pollinators, bumblebees are often seen buzzing around suburban vegetable and flower gardens. Their flight has been characterized in song, and also described as defying the laws of flight. While bumblebees’ aerial antics are certainly worthy of a melody, the supposed theoretical prohibitions on their flight are in error. The idea that bumblebees are theoretically incapable of flight probably stems from a book by French scientists published in the 1930s where the authors applied principles of fixed-wing flight to the bees. More recent analysis shows that bumblebees use exceedingly fast, irregular and rotational wing movements which generate sufficient lift and propulsion for their buzzing, erratic patterns of flight.
Although some people believe bumblebees are incapable of stinging, both queen and worker bumblebees can sting. While camping at a lake at the base of the Beartooth Mountains, my daughter was once stung by a bumblebee. She reported, however, that the sting wasn’t nearly so painful as one delivered by a yellowjacket.
Often misunderstood, bumblebees are an integral strand in the complex web of biological interactions that maintain life on earth. Encountering a bee in the garden or camp isn’t a cause for alarm, but an opportunity to consider their critical connection to human life and our need to maintain a planet hospitable to our buzzing benefactors.
• There are 1,200 native pollinating bees in North America and 30,000 worldwide. A single bee will pollinate 50-100 flowers in just one feeding. The hairs on a bees body trap pollen grains while feeding on nectar, which are then transferred to other flowers.
Brown-belted Bumblebee (Bombus griseocollis)
More Bee Facts:
1.) Bees are the only insects that generate a food (honey) that is consumed by humans.
2.) A bee traveling at a top speed of 15 mph will visit as many as 100 flowers before returning to it’s hive.
3.) The individual members of hive of bees (20,000-50,000 bees) will travel a distance equivalent to 3 trips around the world in order to collect 1kg (35 ounces) of honey.
Bombus borealis on Red Clover (Trifolium pratense)
4.) If he could carry it, 1 ounce of honey would provide enough fuel for a bee’s journey around the world.
5.) Most bees are non-aggressive unless the hive is disturbed. Bees aggressiveness and behavior is influenced by weather (the warmer the more aggressive), genetics (bumble bees are generally not hostile while ground bees are very aggressive) and disturbances to the nest.
6.) Bees are rated 9th in the top 10 most intelligent animals. Despite the fact that their brains are the size of a sesame seed, they have the ability to calculate travel distance and the best ways to find sources of food.
7.) Bee pollination accounts for 1 out of every 3 bites of food.
8.) Drones vs. workers: workers leave the hive to gather food. Drones never leave the hive, have no stinger, and are responsible for mating only.
The New York Times recently ran an article entitled, “So Much Life on a Little Patch of Earth.” It outlined the wide array of flora and fauna in the author’s small, typical suburban yard, including a moth that was the first record for North America. So many of us feel that nature is…somewhere else. We travel to find new and novel creatures, when indeed they can be found in our own backyards.
Our yard in suburban Detroit is very small, but we have provided a tiny pond; many native trees, shrubs, and plants; and lots of vegetative structure. Naturally, we’ve kept a yard list of birds, which is currently at 136 species. A couple of years ago, we decided that we’d try to identify all the Hymenoptera in the yard – bees, wasps, ants, and relatives. We are up to 89 species even though we haven’t attempted to figure out ants or the plethora of very small wasps and bees that tend to make the project more tedious than fun.
Among these is a wasp in the genus Euodynerus that has yet to be described by science. We see this species, known simply as “species F”, every year and have sent specimens to the researcher who will be writing the official description.
Two others were some of the first Michigan records for one of the grass-carrying wasps, Isodontia elegans, and the non-native Giant Resin Bee (Megachile sculpturalis). These discoveries scored me co-authorship on two papers on their distribution. Many other species were simply new and exciting to us.
The Hymenoptera were our starting point. Since so many flies are mimics of bees, we’ve started keeping track of all of them, too. And while we haven’t yet assembled lists, we are also on the lookout for beetles, bugs, and other arthropods.
While we’ve probably documented most of the common species, we still have frequent moments of triumph when we encounter something new. And we love the sense of stewardship our inventory brings us. Take a look in your yard, and see what you can discover!
Cicada Killers – there are eastern and western species – are very big wasps, with the larger females reaching four centimeters. When the slightly smaller males gather in “leks” of dozens of individuals, all buzzing around and defending small territories, the effect is intimidating. These insects are truly frightening to folks who don’t know what they are, but rest assured for all their size and hectic activity, they are sheep in wolves’ clothing.
Like all bees and wasps, male Cicada Killers cannot sting, although if handled they may bluff with a false stinger than cannot break the skin. Females can sting, but must be strongly provoked or stepped on. I’ve spent lots of time observing and photographing Cicada Killers in the midst of a busy congregation and never been stung – although I was a little creeped out when they landed on my back. In any event, the sting is very weak, bearing the punch of a mere pin prick, with any discomfort diminishing within an hour. Reports of painful stings inevitably turn out to be similar-looking hornets or wasps. Cicada Killers are no threat except to sensitive allergic people. Cicada Killers emerge from burrows up to three feet deep at the same time as cicadas begin their own above-ground chorus. Favored spots are in loose or sandy soil on gentle slopes with little vegetation. Trees or woodlots which harbor cicadas are always fairly close by. Cicada Killers are not social wasps, but tend to be found in aggregations where suitable habitat patches are located.
Male Cicada Killers emerge first, and await the females. Females hunt cicadas and bring them to burrows they have constructed; they possess large spurs on their hind legs for shoveling soil out the entrance hole. While female Cicada Killers are large, cicadas are larger and heavier. Several times I have heard a cicada song sputter, followed by a buzzy, struggling ball crashing to through the leaves, ending with a big commotion in the undergrowth: a female Cicada Killer subduing her prey. I’ve watched as she dragged her paralyzed quarry to a sturdy weed stalk, sometimes several feet away, hauled herself and the cicada up the stalk, finally taking flight with the cicada clutched underneath her.
In each nest chamber of a burrow, female Cicada Killers place either one cicada on which an unfertilized egg is laid (this produces a male) or two cicadas and a fertilized egg (these will be females). They lay about a hundred eggs in a season, most of which will be males.
In less than three weeks after they emerge, males die; females live another week or two. Underfoot, cicada killer larvae slowly consume their rations. It will be another year before a new generation appears, intriguing some of us, and fooling others to fear them.
Please don’t molest a colony of cicada killers. They are only dangerous to cicadas.
A couple of years ago, my husband and I set out to see how many species of wasps and bees we could document with photos in our small urban yard. We’re up to nearly 90, which covers all the conspicuous and easy-to-ID stuff. One of the challenges has been to differentiate among all the black and yellow wasps. The yellowjackets and other hornets aren’t too bad, but there are many species of potter and mason wasps in the family Eumeninae that are very similar except for the number or arrangement of yellow spots or stripes on a black body.
A series of good photos from multiple angles often cinches the ID. Occasionally we have to resort to netting an individual, chilling it, and looking at some features under a microscope while consulting detailed keys.
That is how I discovered a remarkable structure found on some bees and wasps, especially the Eumeninae: the acarinarium.
Acarinaria are special structures on the body of bees and wasps that function exclusively to harbor mites. They may be a hollow chamber, a hairless area that is easy for mites to cling to, or a series of pits along the edge of an abdominal segment. In my photo of the potter wasp above, the mites are carried on the thorax.
The mites on the wasp are benign – they are in a non-feeding phase while on board. If the mites are on a male wasp, they transfer to the female when the wasps mate. Potter and mason wasps are not social wasps; each female constructs a separate nest made of mud, in the ground, in wood, or some other cavity. As the female provisions her nest, the mites disembark. There they continue to develop, and once the immature wasp pupates, the adult mites feed on the young wasp. Amazingly, this apparently does not harm the wasp. A new generation of mites hitches a ride out of the nest on the wasp when it emerges.
Evolving modified body parts to accommodate mites makes sense so long as the mites are beneficial. It’s presumed that the mites perform a service in the nest prior to them feeding on the wasp, such as combating fungi, predators, or parasites that might damage wasp eggs or young. Each genus of wasp is associated with a particular genus of mite, so this relationship is very specialized. Yet the precise mechanism of this mutualism is still poorly understood.
I thought the bee was attacking me. As I dashed out of our garage it suddenly hovered before my face seemingly challenging me. It looked like a bumblebee and what caught my eye was the white face. It soon moved away, but after a few trips I realized that every time I walked from the garage to the house, he was there to greet me.
I quickly found out that this is common behavior of male carpenter bees as they protect and patrol their small territories looking for intruders or mates. There’s no reason to be alarmed; males don’t sting. Only the dark-faced females can muster a sting and usually only if handled, something only an entomologist would do. Male territories usually encompass about 60 feet around the nest site or food-plant area. Despite having larger eyes than females, they will chase any interloper that comes near – birds, flying insects, people, and even towards the occasional airplane high in the sky.
There are hundreds of species of native bees in eastern North America, but there are only two species of carpenter bees – Southern Carpenter Bee (Xylocopa micans) found in the Southeast and the Eastern Carpenter Bee (Xylocopa virginica) from New England southward.
They’re fairly easy to identify. At first blush they look like large bumblebees, but if you look more closely you’ll notice that they have shiny, black and mostly hairless abdomens. Peer even closer and you’ll see their massive and sharp galea hanging down from their mouth. These are used to chew their way through wood, giving them their namesake.
Carpenter bees don’t eat wood. They just chew through it to create tunnels for nesting and resting in dead trees or branches, log, or unfinished wood on structures. They prefer softwoods like pine, fir or cedar, which are easier to excavate and have straighter grain. With their sharp galea, females chew a round entrance hole about a half-inch in diameter. It can take up to two days to chew across the wood grain. Once the tunnel is about the length of their body, they turn ninety degrees and excavate more quickly with the grain. If they come to a knot, the tunnel may go around it. Some nests have two or more tunnels that parallel the main hall, each over a foot long. They can use the same nest site year after year perhaps by just adding a new tunnel or lengthening one. One colony was used for 14 years.
Carpenter bees are solitary bees. Unlike bumble bees there are no queens or workers, just individual males and females. Newly hatched females may live together in their nest with their mother during their first year. But each female will have its own nest and brood.
At the end of a tunnel the female lays a huge egg on a loaf of pollen the size of a kidney bean. At just over a half inch it’s one of the largest insect eggs in the world. When it hatches the grub will feed on the pollen as it grows. The female chews the surrounding wood into a pulp to create a cardboard like partition that seals the egg within its own cell. Each tunnel can have up to eight cells.
Here’s what gets them in trouble. Carpenter bees can create nests in fences, outdoor furniture, and buildings. They select bare wood on roof eaves, fascia boards, porch ceilings, decks, railings, siding, shutters and other weathered and bare wood. They will seldom if ever bore into painted or varnished wood. Which makes their often minor damage both avoidable and solvable.
It takes years for carpenter bees to cause significant structural damage. You can minimize their damage by filling and sealing nest holes in the fall or winter with a small dowel or caulk. Filling them in the spring or summer will just cause them to make a new entrance hole. You can also provide alternative nesting sites in untreated cedar boards, their favorite wood.
Why not just eradicate them? From spring lupines to late summer goldenrods, carpenter bees are pollinators of plants representing 19 different families. Like most bees, they enter the opening of a flower and reach in with their glossa, like a long tubular tongue, to suck nectar. They also gather pollen to carry away on their bristled-covered rear legs.
Carpenter bees are also cheaters. If the flower is too small or too long for them to reach with their relatively short glossa, they simply rob them. After crawling up the flower they stab the base of the flower with their galea and gain access to the nectar. Sometimes other bees will feed at these holes later too. The flower loses the nectar it uses to entice insects to visit without being pollinated as the stamen and anthers are bypassed by the thieves.
Over the last decade carpenter bees have been moving farther and farther northward. Keep watch for the hovering male signaling his territory around you.
It’s hard to say if laziness, divine intervention, or concern/apathy for the environment led me to turn the mower off and leave my lawn alone. Probably a little bit of everything.
Here in south Florida things are still growing. Flowers still bloom and insects still hop, fly and flit across the lawn. During the summer months you can in fact “watch the grass grow” but with shorter days and fewer rain clouds the need to mow has gone from every four days to every three weeks.
As the dry season kicked in a few weeks back, frost-like blooms took over a corner of the lawn. Days passed and the snowy appearance spread. I mowed, but the prostrate plant avoided the whirling blades and left behind a colorful white and violet ground cover. It was beautiful.
The star-shaped flower is Mexican Clover (Richardia sp.), and despite the name may or may not be a native. It is found in Central and South America as well as the southern United States but may have extended its range down into Florida in the last few decades. Some say it was here before the Spanish explorers and deserves native status. Others think it was introduced.
As I mow on this particular Sunday I find myself humming a certain song as I make pass after pass. Each consecutive lap brings me closer to the field of Mexican Clover that covers nearly half the lawn. I watch hundreds of bees dart from bloom to bloom and slurp nectar from the flowers. Monarchs, White Peacocks, Gulf Fritillaries, Buckeyes, Skippers and other butterflies do the same. It’s like musical chairs for insects.
It’s a spectacular site. My lawn is a refuge. My lawn is a cafeteria. My lawn is beautiful.
Native or exotic – the flowers benefit the bees and butterflies. The humming in my head matches the humming of the bees. It drowns out the mower. I hear my mother say to me, speaking words of wisdom – let it be.
Summer came late and left early. A few days ago storms pounded the high country. When the clouds veiling the mountains finally parted, the peaks were crowned with newly fallen snow. It had mostly melted by the next day. At the weekend the roads were dry, the skies were blue, and the air was warm. It was almost as if the snow had never fallen. I wandered, lonely as a cloud, through the high meadows, pastures, and woodlands and was cheered by hosts of surviving flowers, although here and there were the dead or dying, mortally wounded by the cold.
A bumble bee patiently and carefully tended to a thistle blossom. The bee’s presence surprised me. I had imagined the cold would have driven the bees away but I was mistaken. I watched it for some time, until it finally flew off. Not far from the first flower I came across another thistle, this one too being attended by a bumble bee, only a larger and differently colored insect. Again I found myself surprised. I was only aware of three bee species, honey bees, invading African bees, and bumble bees. Was it possible that there were two types of bumble bees?
Utah is home to 900 bee species, over 20% of the 4,000 bee species found in the United States. I deliberately use the phrase “bee species” as these numbers are specific for bees and do not include their distant cousins the wasps, hornets, ants, and other members of the order Hymenoptera. World-wide some 19,000 species of bees have been identified and it has been estimated that as many as 10,000 additional species remain to be discovered. In a recent survey of the San Rafael desert, which covers roughly 2,000 square miles in central Utah, 316 species of bees were found. Over 40 of these species had never before been reported.
To put these bee numbers in perspective: 446 bird species have been documented in Utah, while roughly 660 have been observed in the continental United States. There are 10,000 avian species known throughout the world. There are nearly twice as many known bee species as birds. The distinction between the various apian species lie in attributes such as tongue length, the number and length of antennae segments, and the detail of and venation patterns in the wings. Those who study bees typically forego binoculars and field guides, instead requiring microscopes and detailed entomological keys.
Fewer than a dozen of these many species are honey bees, members of the Apis genus. Honey bees are not a species native to the United States. They began to be imported from Europe soon after the Pilgrims arrived in Massachusetts. The majority of the North American bees are native, naturally occurring species. Although far less frequently mentioned in the popular media than honey bees, these native species are of great ecological and economic significance. Many flowering trees, shrubs, and crop plants are more efficiently pollinated by native species than by the non-native honey bees. In some cases a highly specific relationship has evolved between a species of flowering plant and native bee. Without the precise species of native bee visiting its flowers and carrying its pollen to its sisters, the plant would soon disappear from the face of the earth.
I had wondered if there are two bumble bee species. There are eleven known in northern Utah alone. Differentiating between them is based on the coloration of abdominal segments and differences in thoracic markings. I now have something to watch for besides my feathered friends.
“Guardian of the Forest” or Ix-canan is the name that Mayans gave to the Firebush, Hamelia patens. But as its common name suggests this plant is on fire. Or at least it appears that way. Even in the coldest days of winter here in South Florida its embers of life are smoldering deep within its roots. The cold stopped its growth dead in its tracks during the freeze this past winter but some of the leaves hung on, changing to lighter reds and greens in hopes of catching those different wave lengths of light. Growth was slow and steady during the spring months but as soon as the heat and wet of summer hit, it exploded with green growth and blossoms.
Each blossom strikes up a flame of such intensity, that the hummingbirds, butterflies, bees and ants just can’t ignore. The anoles wait patiently on the branches in hopes of catching those nectar seeking ants and once in awhile land a butterfly. As I looked closer on this plant and watched the pollinators, I observed that the ants were crawling in and out of holes just above the ovary. These holes were absent from the newly formed flowers. I then watched as a carpenter bee, too large to climb down into the tubular flower, appeared to pierce the base with its mouth parts. I thought this was clever for the bee and fortunate for the plant that the ants were distributing the pollen while they crawled around. There seemed to be more than enough nectar to go around.
Towards the end of summer and into the fall the berries attract song birds. They are not particularly sweet enough for my tastes but I can see making a jam or jelly from them. The firebush also has many medicinal uses that have been discovered by the indigenous people of Central and South America, the West Indies and Mexico. These uses are many and include treating burns, another reference to its name, to healing headaches. With its gift of abundance it’s easy to feel gratitude for this marvelous plant.
Have you heard the buzz about declining pollinators? Biologists fear several butterfly and bumble bee species, including the once common Western Bumble Bee, have disappeared from parts of their range. Why should we care so much about bees, butterflies, and hummingbirds? Pollinators are vital to maintaining healthy ecosystems. They are essential for plant reproduction, and they produce genetic diversity in the plants they pollinate. The more diverse plants are, the better they can weather changes in the environment. Pollinators are also keystone species, which are species upon which others depend. For example, when a bumble bee feeds on the nectar and pollen of huckleberry flowers, it carries pollen from one flower to the next. A fertilized flower then produces fruit that is, in turn, eaten by cedar waxwings, grizzly bears, and dozens of other animals, including humans. Insects and other animals pollinate an astounding one-third of the food we eat, including all kinds of fruits, vegetables, grains, nuts, beans, and coffee!
Pollinators need our help, and we can do our part by creating pollinator friendly gardens and protecting native wildlife habitat. You can start a pollinator-friendly native plant garden in your backyard, schoolyard, or public park. It’s important to garden with native plants because pollinators have evolved with native plants, which are best adapted to the local growing season, climate, and soils. Most pollinators feed on specific plant species—hummingbirds sip nectar from long, tubular flowers such as honeysuckles, green sweat bees prefer the tiny ray flowers of sunflowers, and the pickiest pollinator of all, the yucca moth, feeds and nests only on yucca plants. Find out which plants are native to your area by contacting your native plant society or county extension office. Even small backyard gardens can contribute significantly to the maintenance of important habitats for wildlife. And gardening connects us to nature and helps us better understand and value natural systems.
You can also help scientists and pollinators, especially bees, by contributing observations to projects like the Great Sunflower Project (http://www.greatsunflower.org/). By watching and recording the bees at sunflowers in your garden, you can help scientists understand the challenges that bees are facing. Meanwhile, grow a few pollinator-friendly native plants in your garden and watch what happens. You might just get hooked on pollinators.