Temperate regions of the world are characterized by distinct seasons throughout the year. Each season has good and bad points. Winter has beautiful snow-covered landscapes, freezing temperatures, and ice on roadways. New leaves, flowers, thunderstorms and tornados are hallmarks of spring. Summer is a time for water sports and hot and sweaty days. Autumn is harvest time, falling leaves, and bees and wasps.
Why is it that we always seem to be overrun with bees and wasps as the days decline during the fall season? The answer can be found in the biology of some of the social bees and wasps.
Many of the insects that we call bees and wasps live a solitary life. As the name suggests, these insects live and work alone. Familiar examples include mud dauber wasps, carpenter bees, cicada killer wasps, and sweatbees.
Other bees and wasps are social insects. Such insects live in colonies with a queen and a batch of workers. Of the social bees and wasps, only one species has a permanent colony and that is the honeybee. Honeybee colonies exist as a unit over the winter months.
All other social bees and wasps have colonies that do not survive the winter. These are known as annual colonies. Insects in this category are bumblebees, yellowjackets, bald-faced hornets and paper wasps.
In general, this last group includes the bees and wasps that we encounter in high numbers during the fall months. Each colony is started by a queen that had survived the winter hiding in some secluded site, such as under leaves in the woods or hay bales in a barn. That queen then selects a nest site, deposits a few eggs and raises the first workers. These workers then take over the jobs of collecting food and feeding the babies.
During spring and summer, such colonies generally go unnoticed because the number of insects in them is small. By fall, there can be hundreds of bees or wasps in each colony and human encounters increase dramatically.
In general, social insects sting when defending their nest or when they are individually physically abused. So, in general, the best advice on how not to get stung is to leave the individuals alone – don't swat at them when they hover around your cola can or picnic salad. And don't disturb the colonies by doing something like running a lawn mower over the entrance to a nest in the lawn. Think "yellowjackets" here.
The poet Robert Frost recognized the difference in behavior of bald-faced hornets – he called them white-tailed hornets – between individuals away from the nest and around the nest. In his poem, "The White-Tailed Hornet," he describes encounters with the insect under two circumstances. At the nest, Frost describes the behavior this way:
"The exit he comes out at like a bullet
Is like the pupil of a pointed gun.
And having the power to change his aim in flight,
He comes out more unerring than a bullet."
Frost points out a different behavior away from the nest:
"As a visitor to my house he is better.
Hawking for flies about the kitchen door,
In at one door perhaps and out another,
Trust him not to put you in the wrong.
He won't misunderstand your freest movements.
Let him light upon your skin unless you mind
So many prickly grappling feet at once."
The stinging behavior of these insects is the reality behind the old saying that admonishes people to not "stir up a hornet's nest." Stirring up a hornet's nest is a sure way to get stung.
That is the reality people faced years ago when mowing red clover hay or plowing up such fields in the fall. Red clover is pollinated by bumblebees, so fields of the crop were home to many nests. The bees were unhappy when their nests were disturbed and expressed their displeasure by attempting to sting anyone or anything in the vicinity. Many are the stories about teams of horses running away from the stinging bees.
While I never had to plow a clover field with horses, I did plow such fields using a tractor without a cab. I can report from experience that stirring up a bumblebee nest with a plow is a sure way to get stung, and stung and stung!