By Frances Lamberts
Excited buzzing by honeybees customarily announces, from a good many feet away, the Carolina Buckthorn’s mid-June flowering time, the greenish-white, inconspicuous blossoms followed by purple berries much relished by robins in the fall.
There was no such humming announcement from the tree this year, awareness of buzz and blossoms coming with chance weeding directly under it. Perhaps the cloudy days and long-persistent rain were keeping the bees away.
Many insects and the honeybees, and fruit-setting by numerous crops they pollinate, face greater threat than the vagaries of weather, though. Systemic pesticides of the neonicotinoid class, widely used in modern industrial agriculture, affect their central nervous system, accumulate in pollen and nectar of treated plants, and are thought to play a major role in bee population decline worldwide.
Much recent field and laboratory research by natural scientists has documented how critical normal functions of bees, including their famed dance communication in the hive, are being negatively affected by even low-dose, chronic exposure to these pesticides.
As the scientists point out, bees must be well coordinated in walking and climbing, inside the hive and on flowers as they forage, yet exposure to the pesticides impairs their locomotion ability. Worse, it affects their navigational memory: At certain (sub-lethal) exposures the bees don’t seem to remember salient landscape features for correct turns for the “homing” portion of returning to the hive. It affects their odor perception, an important part of learning the flowers they visit, and impairs their ability to avoid predators, like hornets, they might encounter.
Honey bees possess a perhaps unique ability, through “waggle” and other dancing to communicate the distance and direction of profitable new flower patches, upon return to the hive. Yet research now finds that, if exposed to neonicotinoid pesticides “comparable to what they would naturally receive in nectar from treated fields” they perform up to 10 times less of this dance or may even stop dancing altogether.
In Europe, three neonic pesticides are banned for outdoor uses since 2018. To protect pollinators and water sources, Canada’s Pest Management Council has also proposed their ban. As the Natural Resources Defense Council and other sources indicate, the United States however is failing to take similar action.
Although acknowledging the serious risks of these pesticides to bees and other pollinating wildlife, the Environmental Protection Agency, still, is “green-lighting” their continued and widespread use.
The Linden trees’ flowering came and went, too, without past years’ bee buzzing excitement.