Editor’s note added April 18, 2023 (below).
My heart sank. It was a sight no beekeeper wants to see. Hundreds, if not thousands, of dead and dying bees on the ground outside the entrance of one of my hives.
The diagnosis — pesticide poisoning — did not take long. The telltale signs were the quirky motions of dying bees and extruded tongues (yes bees have tongues) of dead bees.
Even now, it is difficult for me to watch video of the little ladies I cared for dying slow, agonizing deaths.
How did this happen?
Pesticide Exposure
Honey bees die from exposure to pesticides in one of two ways: direct contact or indirect contact with residues.
With direct contact, typically as spray over a crop canopy, bees die in the field and do not return to the hive. Though tragic, the queen, brood and nurse bees are not contaminated and the colony can survive.
With indirect contact, bees like mine are exposed to residues on treated crops, then carry it back to the colony on their bodies and as contaminated pollen and nectar. Whether the colony survives or not is largely left to chance.
What makes this scenario difficult to swallow is there is absolutely NOTHING that I can do to prevent it or be compensated for my loss.
Though Ohio law requires pesticide applicators to notify beekeepers when they use products toxic to bees, this does little for urban beekeepers. The law applies to fields in bloom, greater than half an acre in size and within a half mile of an apiary. For those of us who live in subdivisions, with bees that often travel miles to gather pollen, nectar and water, this law has no teeth.
Even more difficult? The problem is getting worse. Researchers at Pennsylvania State University have discovered that insecticide use by agriculture has become increasingly toxic to honey bees when pesticides are ingested. The primary driver of this change is neonicotinoid use as a seed treatment for corn and soybeans. Over the past 20 years, there has been a 120-fold increase in the oral toxic load for bees in the Heartland — my back yard. This region includes all of Iowa, Illinois and Indiana, most of Missouri, and part of Minnesota, Ohio, Kentucky, Nebraska and South Dakota.
Image: Douglas et al. 2020, Scientific Reports: https://www.nature.com/articles/s41598-019-57225-w.
Commonly called neonics, this new class of synthetic insecticides is especially problematic because it is a systemic, which is dissolved in water and absorbed by the plant. The entire plant — foliage, pollen, nectar and fruit — is essentially toxic to bees.
Concerns about neonicotinoids led the European Union to ban three of them in 2018. Canada followed suit, with goals of phasing them out by this spring. The EPA plans to implement new measures to reduce risks, but has thus far allowed the five neonics (acetamiprid, clothianidin, dinotefuran, imidacloprid, and thiamethoxam) to be marketed in the US.
A Costly Mess
Since this was my first experience with pesticide poisoning, I did not know what to expect or how to deal with the problem. Research gave me very little, so I did nothing initially and waited to see if the colony recovered on its own.
The death rate slowed to near zero in the coming week and I thought I was in the clear. What I didn’t realize is that there was a ticking time bomb inside the hive. The bees that made it back to the hive brought with them poisoned pollen and nectar and stored it in the hive. It was then fed to the baby bees (larvae) and that induced the second die off about two weeks later.
At this point, the hive was a hot mess. There was no sign of a queen, no eggs and several capped and chewed swarm cells. This meant half the colony was nearing or had already swarmed to find a new home and the other half was in the process of making a new queen.
Standing on the sidelines was no longer an option. I had to intervene and get rid of every potential ounce of pesticide if the colony was to survive. Though some suggested washing frames and removing honey, pollen and beeswax, my bee mentors recommended tossing everything and starting from scratch.
So I pitched everything but two frames with brood. Not one more bee or any human was going to come in contact with this stuff.
On the curb on trash day was $500 worth of honey, $54 worth of frames and perhaps the most prized product — drawn comb, or beeswax, which is pound for pound more valuable than honey. Even sadder, all the work my ladies did was for naught.
I hoped the hemorrhaging would stop and my efforts would help to save the colony. I added frames with drawn comb to the hive, fed them sugar water with Honey-B-Healthy, a feeding supplement with essential oils, and narrowed the opening to their hive to would-be robbers. I waited and prayed they would recover.
Sooooooooo?
Mother Nature won this battle, this time. Two weeks later, I found a new queen. A week later, I found eggs and teeny baby larvae. It is now two months after the incident and the colony is again one of my better ones. I have added another box for brood and will soon add a box for honey. I named this queen “Victoria” to celebrate her victory over human carelessness.
The colony ruled by Queen Victoria in the foreground of my apiary. The top box was added recently when the colony was running out of room to raise their young in the lower box. Soon a top box will be added to collect honey.
What You Can Do
While pesticides are here to stay, there are measures you can take to reduce the likelihood of poisoning of bees and other beneficial insects. Keep in mind that insecticides are the most problematic. Herbicides and fungicides are less likely to be toxic.
Avoid Spraying Blooms
Because bees are drawn to them and have direct contact with them, avoid spraying blooms when possible.
Apply Pesticides in the Evening
Honey bees forage during the day when temperatures are above 50°F. As the sun sets, they return to their hives for the evening. Applying pesticides in the evening can greatly reduce potential exposure.
Choose the Appropriate Formulation
Pesticides are available in a variety of formulations. Granular pesticides are the most bee-friendly because they are applied to the soil and seldom used on blooming plants. Solutions and emulsifiable concentrates rank second because they dry quickly. Dusts and wettable powders are more dangerous as they adhere to the tiny hairs on a bee’s body and are thus easily transported back to the colony.
Check Active Ingredients
Use less-toxic, faster-degrading pesticides. Many of the newer residential pesticides have a faster residual time and may take just a few hours to degrade.
The biological insecticide Bacillus thuringiensis (trade names Biobit, Condor, DiPel, Javelin, and VectoBac, among others) exhibits very low toxicity to bees. To see how pesticides stack up for toxicity, read this listing.
Avoid neonicotinoids altogether.
Read and learn. In my research, I found one insecticide that touted itself for being active for 10 years. Geez Louise, do you really want to be using that?
Go Organic and Use Your Voice
The Washington DC-based organization, Beyond Pesticides, operates with a mission of protecting health and the environment with science, policy and action. Their website is especially useful for learning about pesticide alternatives and becoming involved with policy change.
What Scientists are Finding and Doing
Because honey bees are on the decline, scientists are looking for new ways to protect them. I have highlighted a few novel projects below.
Pollinate Crops and Protect Bees
Scientists at Cornell University have developed a microparticle that includes enzymes that detoxify pesticides that are commonly ingested by bees. It works by protecting bees from the inside (stomach) out. The size of a grain of pollen, the medicine is attractive to bees because it contains pollen patties and sugar water. The project is intended for industrial agriculture as a means of managing pollination of crops.
To learn more, read here.
Nonchemical Opportunities for Beekeepers
Occasionally, it is beekeepers themselves who use insecticides to manage another insect, the deadly varroa mite destructor. The treatment is not ideal as the bees are at some risk and the mite has now begun to evolve resistance to the usual pesticides. Entomologists at Washington State University-Pullman are working with a mite-killing fungus that offers promise as a nonchemical treatment. The study revolves around strains of the common soil fungus Metarhizium acridum. The fungus is placed in a mesh bag in the hive. As bees try to remove the bag, mold spores drift down on mites, causing infection and death. The biopesticide proved to be just as effective as oxalic acid, one of the commonly used methods today.
To learn more, read here.
If you have learned of additional efforts, I would love to hear about them. Shoot me an email or make a post and spread the word!
Editor’s Note: Upon this incident, I filed a complaint with the Ohio Department of Agriculture. Bees were collected and sampled for pesticide residue and found to contain the chemicals imidacloprid (1.427 ppm), azoxystrobin (6.536 ppm) and propiconazole (4.212 ppm). Though it could not be determined who administered the pesticides, an industry expert told me imidacloprid mixed with a fungicide is commonly used to treat soybeans in late bloom. There is consensus that negative effects on honey bees occur above 0.02 ppm imidacloprid in nectar. My bees contained 72 times this concentration, so were likely killed by imidacloprid.