Toxic Effects

The honey bee has been compared to the coal miner’s canary. Coal miners used the fragile birds as indicators of the condition of mines. As long as the canaries could breathe the mine’s air and continue singing, the atmosphere was considered safe enough for the miners to breathe. The death of the canary meant that the mine was in trouble. The death of honey bees may indicate that the environment is in trouble. Beekeepers experienced heavy losses of colonies throughout the Mississippi River Delta region this past summer. During a summer that set records as the hottest in recorded history, pest insect populations exploded in the Mississippi and Arkansas Deltas. Army worms and soybean loopers covered cotton and soybean plants, often stripping the plants of leaves. In response, growers sprayed broad-spectrum insecticides on these plants, which are highly attractive to honey bees and other pollinators. Broad-spectrum insecticides kill all insects, including beneficial pollinators, not just the targeted species. Some of the sprayed pesticides are considered persistent, meaning that they remain in the environment for a long time. For the honey bees, the summer-time insecticide sprayings were particularly damaging. Many of the crops sprayed with insecticides for the summer’s break-out of insect pests had previously been treated with systemic insecticides. Here, insecticide-coated seed poisoned the entire crop plant. Honey bees cannot detoxify multiple toxins in their bodies. With their immune systems severely damaged, the bees were attacked by multiple pathogens: bacteria, viruses, and funguses. Sick bees left the hives to die without contaminating the colony. Bees disoriented by neurotoxins were unable to navigate back to the hive and died.

The spraying of broad-spectrum insecticides in the summer resulted in heavy losses for the Delta beekeepers. Native pollinators were surely decimated as well. Continuous use of pesticides results in replacement of pest populations with new, chemical-resistant pest populations. My queen evaluation bee yard, shown dusted in light snow, lost more than one fourth of its colonies of workers, drones, and queens.

--Richard