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Honey Bee On Flower Honey bees are essential to modern agriculture. These industrious social insects produce over $100 million worth of honey and beeswax each year in the United States. Their service as pollinators of agricultural crops adds another $10 billion to their overall value. Due to the destruction of native habitat, native pollinators such as bumblebees and leafcutter bees are in short supply, further magnifying the impact of the honey bee and the work of our beekeeping industry.


The honey bee is about 12 mm (1/2 inch) long and usually yellow, with 3 or 5 dark brown abdominal bands. They carry two pairs of wings and lack the constricted abdomen (wasp waist) of the wasp and hornet. Honey bees can sting, but are much less aggressive than wasps and hornets.

Honey Bee hard at work inside its bee hive
Closeup Of Honey Bee

Life Cycle:

It takes 21 days for the honey bee to develop into a "hive bee" upon hatching from the egg. The "hive bee" spends the next 21 days doing hive chores and feeding larvae. After the "hive bee" period, the bee passes into the category of "field bee," or forager. These are the bees who leave the hive to return with nectar, pollen and water. In the height of nectar flow, these bees wear their wings out from flying and die within three weeks.


When a colony becomes overcrowded, the "field bees" gorge on honey and leave the hive with the queen bee to establish a new colony. Because they are gorged on honey, they are not generally aggressive and pose no threat to humans if left alone. A typical swarm may contain thirty to fifty thousand bees and will constitute a definite loss to the beekeeper whose apiary they have left.

Honey Bees & Pesticides:

"Pesticide" is a general term used for a chemical designed to kill target pests such as insects (insecticide), mites (miticide), weeds (herbicide) and organisms which cause plant diseases such as bacteria (bactericide) and fungi (fungicide). Unfortunately, many agricultural pesticides may be toxic to bees. Each year many honey bee colonies are damaged or destroyed by pesticides, primarily insecticides. Such losses have a devastating impact on the beekeeper, who may have to relocate damaged hives or perhaps even be forced out of business. Growers of most insect-pollinated crops (apples, raspberries, cucurbits, alfalfa seed and many others) experience lower yields, and ultimately the consumer must pay higher food prices.

Potential Factors for Honey Bee Damage:

Many factors involving insecticide application affect the potential for honey bee losses. The most important factors are outlined below:

1. Plant Growth Stage: Severe bee poisoning most often results from spraying insecticides directly on flowering plants. Insecticide applications are generally not recommended on blooming crops.

2. Relative Toxicity of the Chemical: Pesticides vary in their toxicity to honey bees. Most fungicides, herbicides and miticides are relatively nontoxic to honey bees and can generally be used around them without serious harm. The biological insecticide Bacillus thuringiensis exhibits very low toxicity to bees. One group of insecticides which is highly toxic to honey bees cannot be applied to blooming crops when bees are present without causing serious injury to colonies. Among the materials in this high-risk category are diazinon, Imidan, malathion and Sevin.

3. Choice of Formulation: Different formulations, even of the same pesticide, often vary considerably in their toxicity to bees. Dust formulations are typically more hazardous than sprays because they are picked up on bee hairs. A wettable powder such as Sevin 80S would usually remain toxic in the field for longer time than Sevin XLR Plus, an emulsifiable concentrate. However, granular insecticides are less hazardous to honey bees. Microencapsulated materials such as Penncap-M are particularly dangerous to use around bees because the capsules have a special tendency to adhere to bees due to their size and electrostatic charge, and because the contaminated pollen collected by bees in the treated fields is stored in the hive and remains toxic for an extended period.

4. Residual Action: Residual activity of an insecticide is an important factor in determining its safety to pollinators. An insecticide which degrades within a few hours can generally be applied with minimum risk when bees are not actively foraging.

5. Drift: Drift of spray applications can cause significant bee poisoning problems, particularly when drift reaches colonies or adjacent flowering weeds. In general, sprays should not be applied if wind speed exceeds 10 mph and favors drift towards colonies.

6. Temperature: Temperature can have a substantial effect on the bee poisoning hazard. If temperatures following treatment are unusually low, insecticide residues can remain toxic to bees many times longer than if higher temperatures prevail.

7. Distance from Treated Fields: The most severely damaged colonies are usually those closest to fields where insecticides are being applied. However, during periods of pollen or nectar shortage, hives within five miles of the treated area can be injured.

8. Time of Application: Evening application of a short residual insecticide can greatly reduce any potential for bee damage.

Updated January 1, 2017

© 2010-2017 Albert W. Needham