7 Ways farmers can protect bees from chemicals

Many pesticides and other chemicals commonly used in agriculture are toxic to bees. Exposure can result in the damage or decimation of honeybee colonies. Not only can this have a profound affect on the livelihood of beekeepers, but the yields of insect-pollinated crops will be negatively affected. While growers must do what's needed to protect their crop, steps can be taken to help safeguard bees as well.

The experts at the University of Massachusetts Amherst Extension offer these bee-saving tips for farmers:

1. Communicate with beekeepers

It's important to talk with local beekeepers about pesticide application. Giving them us much lead time as possible before application means they can move or otherwise safeguard their hives. Remember that even if colonies aren't in the immediate vicinity, they can still be affected. If there's a pollen or nectar shortage, bees can travel up to five miles and bring back chemicals that can injure the hive.

2. Spare the blooms

Do not spray insecticides directly on flowering crops. This causes severe bee poisoning and is prohibited according to the labels of certain products. If insecticides must be applied during blooming to save the crop, choose residual materials and low-hazard formulations whenever possible, and notify local beekeepers ahead of time. Be especially careful with alfalfa, soybeans, and other legumes and pollinating crops.

3. Avoid drifting

Spray drift can cause extensive bee poisoning. Know where the bee colonies are in your neighborhood. Pay attention to how wind speed and direction could send chemicals drifting toward them and any flowering weeds they may frequent. Reducing pressure or changing spray nozzles to increase droplet size can help reduce spray drift. Do not apply if wind speeds exceed 10 mph and are directed toward colonies.

If bees are foraging in flowering weeds around the field such as dandelions, milkweeds, and smartweeds, consider mowing them before application so the bees won't come into contact with chemicals on flowers.

4. Consider the formulation

Different formulations of the same pesticide can vary greatly in how they affect bees. Dusting is generally more hazardous than spraying because bees pick up the dust on their hairs. Microencapsulated materials are especially hazardous because their size and electrostatic charge cause them to stick to bees, and contaminated pollen remains toxic for some time when stored in the hive.

5. Know the residual activity

The residual activity of an insecticide is important to consider. If it degrades within a few hours, for example, there is generally minimal risk to bees as long as they are not actively foraging.

6. Time your application

Applying insecticides in the late evening or early morning when bees aren't actively foraging can help reduce damage.

When checking the weather to determine when to apply insecticides, factor temperature into your decision-making process. If unusually low temperatures are expected overnight following application, residues can remain toxic into the next day when bees arrive. Avoid applying when temperatures rise and bees come back to the field and during hot evenings. If you see bees clustered on the outside of their hives because of the heat, be especially careful.

7. Read before you apply

Before applying any chemical, read the label thoroughly and follow instructions carefully. Learn more about protecting bees and browse a list of how chemicals commonly used in orchards affect bees on the UMass Extension website. For a broader selection of products, the University of California has published an online database of how insecticides, herbicides, fungicides, and other chemicals affect bees, including information on the effects from mixing them with other chemicals.