Bees and Pesticides
Honey bees are important pollinators but bees are often exposed to pesticides that can kill. For beekeepers, understanding how pesticides affect honey bees is the first step to reducing risks. In this article, you will learn about the impacts of pesticide poisoning on honey bee colonies along with some tips to help safeguard your apiary.
One of the most frustrating aspects of beekeeping is that we can’t protect our bees from all harm. These free flying individuals are subject to environmental perils. However, with proper beehive management you can lessen the risk of colony loss.
Pesticides Killing Bees
Pesticides are useful substances that are used to protect crops from insect pests. There are many different types of pesticides. You will have heard the terms: neonicotinoids, fungicides, herbicides, organophosphates, etc.
The level of toxicity to bees is different among pesticides. They are generally separated into 3 groups: Group 1 Highly Toxic, Group 2 Moderately Toxic and Group 3 Relatively Nontoxic.
How Pesticides Affect Honey Bees
Bees are affected by pesticides in several ways. Interestingly, honey bees have less genetic ability to denature (breakdown) pesticides than some insects.
The behavior of honey bees sent out into the field may change. They may experience problems with navigation and be unable to return to the hive. In some cases, bee immunity is weakened making them more susceptible to diseases and pests.
Pesticide exposure that may harm the reproductivity capacity of the queen bee. The role of the queen bee as the only layer of fertilized eggs is vital to long term colony survival.
Strategies to Protect Beehives from Pesticides
The only sure way to of protecting beehives from pesticide problems is to keep your honey bees at least 5 miles away from honey bee toxic chemicals.
So much depends on where you live and the landscape surrounding your beehives. It is impossible to eliminate all risks to bees from pesticides.
But, you can use some proactive strategies to reduce the likelihood of colony loss. It is always a good idea to educate your neighbors on bee friendly gardening practices.
Tips to Protect Your Hives
- introduce yourself to nearby farmers and neighbors as a beekeeper
- educate friends and neighbors on the importance of bees and how your bees can help their gardens
- ask them to keep your bees in mind and request that you be notified of spraying or application
- check to see if local farms follow bee safe spraying guidelines
- do not place your apiary in areas used to grow crops that require heavy, frequent pesticide use
- provide a safe clean water source for your bees
- consider relocating hives temporarily during the most high-risk time (growing season)
Confining Bees Inside
In some areas, beekeepers must be notified of planned pesticide application. Sometimes you can’t move hives, but you have a few hours to take action. This also applies to protecting beehives from mosquito spraying.
Thankfully, many chemicals break down and become a bit less toxic over time. You want to prevent your bees from flying during the day of application.
Confined bees need fresh air and water if it is hot. Rolled pieces of screen material can be used to block the hive entrance – yet allow air to flow.
Covering the beehives with wet burlap may also help protect your bees and cool the hive. In hot weather, a large soaked sponge inside the hive will provide some water for cooling.
Plastic is sometimes used to cover hives and protect honey bees from pesticide poisoning but there is a greater risk of over-heating.
Since, in most cases – honey bee do not fly in rain. Setting your garden sprinkler to “rain” on the hive entrance may also aid in keeping the bees home for a day.
Signs of Pesticide Poisoning
The honest truth is – you are likely to have an episode of pesticide poisoning in your beehives and not even know it. But, when you see a devastating attack it will be very obvious.
And no, dead honey bees with their tongues (proboscis) stuck out is not always a sign of pesticide poisoning. This can occur for a multitude of reasons – poisoning is just one.
Individual Symptoms
Individual bees that have been exposed may display noticeable differences in behavior. This includes disorientation, unable to fly, trembling, paralysis, etc.
However, these same symptoms can be the result of various honey bee viruses including pests and disease. Several conditions cause crawling and trembling bees at the hive entrance.
Colony Symptoms
Colony levels symptoms are a bit easier to notice. A sudden significant drop in population with piles of dead bees outside the hive is the most common sign.
Upon inspecting inside the hive, you may discover a large brood die-off and/or signs of poor queen performance.
Acute vs Chronic Poisoning
Acute poisoning occurs when bees forage in recently sprayed or dusted areas. This direct contact with high concentration of pesticide has an immediate, dramatic effect with handfuls of dead bees in front of the hive.
Chronic poisoning is more common. Bees are repeatedly exposed to low levels of pesticides or other harmful substances.
The bees do not die right away. They suffer over time from low-dose pesticide residues in pollen, nectar and water. These results are not as dramatic. But, the colony is weakened and may eventually fail.
How Beekeepers Can Help Colonies Recover
If you suspect your hives have been affected-it is time to take action. Depending on the severity of the exposure, you may still be able to save the colony.
Contamination Issues
Field bees may bring pesticide-laden nectar, pollen, or water back to the hive, potentially contaminating the colony’s food stores. This is very difficult to confirm for most beekeepers.
If you live near an agriculture area where your bees collect pollen from crops that have recently been sprayed – you may have a hint of trouble.
If contamination is evident, consider removing and discarding affected pollen frames. This reduces the danger of long-term exposure.
You can provide pollen substitute by using a dry pollen feeder or purchasing or making pollen patties to help the bees recover.
Strengthen the Hive
One of the more common problems between bees and pesticides is the loss of the majority of the field force. Thousands of workers are needed to carry on daily activities.
Consider strengthening the hive by ensuring it has adequate food, a healthy queen, and minimal pest pressure. Feed your bees honey frames from another hive or a sugar water solution if needed.
This can boost its chances of survival. Adding nurse bees or brood from a healthy hive may help rebuild the population.
Report the Incident
If you suspect pesticide poisoning in your bees, report the incident to local agricultural authorities or your state’s pesticide regulatory agency.
Providing details such as the location, date, and time of exposure, along with any observations of bee behavior or hive damage, can help authorities investigate and take action.
This action won’t bring your bees back. But it helps authorities to ensure that pesticide applicators are following best management practices for pollinators.
FAQs
While many pesticides can harm honey bees, insecticides like neonicotinoids, organophosphates, and pyrethroids are particularly toxic.
Yes, even organic farming practices can involve the use of natural pesticides, such as pyrethrins or neem oil, which may still be harmful to bees if misapplied. Proper application timing and methods are key to minimizing risks.
Yes, laboratory tests can confirm pesticide poisoning by analyzing dead bees, pollen, nectar, or wax for pesticide residues. Beekeepers can work with local agricultural agencies or specialized labs to conduct such tests if exposure is suspected.
Final Thoughts
If only I could always protect my honey bees from all external dangers. Alas, that is not possible. However, we beekeepers can do our part to educate our neighbors on the importance of honey bees. We can also be advocates for bee-friendly practices in agriculture. These efforts help not only the honey bees in your hives but all pollinators in the area.
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