Aerial spraying and honey bees
Have your colonies ever been hit with aerial mosquito spraying? Unfortunately, it’s a common experience. Today’s featured question is about a specific insecticide, naled.
More than half of my bees died from an aerial spray with naled. They sprayed between 6 pm and 8 pm in the evening when the bees were already inside the hive, and there was enough poison 12 hours later, that several thousand bees died in the morning. Today, 5 days after the spraying, the bees are not able to fly and fall to the ground dying. However, this is what EPA has on their webpage for naled mosquito control:Frank
7. Is naled harmful to wildlife?
“Risks to wildlife from aerial application of naled for mosquito control are minimal because naled is applied from several hundred feet above the ground, at low rates, and it does not persist in the environment. However, because naled is an insecticide, invertebrates such as insects, crustaceans, and spiders could be affected. In addition, wildlife present in the immediate treatment area could be affected shortly after spraying occurs but long-term effects are not expected.”
8. How can a beekeeper reduce the risk of bee exposure to naled?
“Spraying naled can kill bees that are outside of their hives at the time of spraying. However, spraying typically occurs between dusk and dawn (when mosquitoes are most active), which is when bees are usually inside their hives. Although EPA does not anticipate that bees will have significant exposure to naled due to the timing of most spray operations, beekeepers can further reduce potential exposure by covering colonies when spraying takes place, or if possible, relocating colonies to a site that will not be sprayed. Providing clean sources of food (supplemental sugar water and protein diets) and clean drinking water to honey bee colonies during application can further reduce exposure.”
Obviously, these studies were not done with real bees or they would have seen that the results are devastating to bees. In my case, naled persisted in the environment for 12 hours and that is how my bees were poisoned the following morning.
Words of wisdom
When it comes to pesticides, it helps to take a lesson from the X-Files: Trust no one.
When you get down to basics, you’ll find that naled is an organophosphate, a type of chemical that is highly toxic to bees. So my first recommendation is to research the chemical family, not just the common name.
Or you can try going to The National Pesticide Information Center. Regarding naled, it says, “Naled is also highly toxic to bees through direct contact (LD50 of 0.48 micrograms/bee). Indirect contact with plants was found to be highly toxic one hour after application and practically non-toxic one day after application. During a field application, naled was low to moderate in toxicity to honeybees after three hours.”
Aerial spraying in real life
It’s easy to forget that conditions during field trials can be very different from real-life conditions. In your case, the person who mixed the chemical could have made an error. The spray tank could have contained a chemical residue from a previous job. The pilot may have flown lower than he should, or he may have repeated an area. Wind conditions may not have been optimal. Any number of things could have caused a bad result.
Bearing in mind everything that could go wrong, I always go to great lengths to protect my bees. Although we don’t have mosquitoes in my area, the Department of Natural Resources occasionally administers ground spray for certain things, usually weeds. But even then, I keep my bees locked up for a day or two to keep them safe.
If it’s hot, you will need to provide ventilation and a water supply, and if it’s really hot, you may need to provide shade as well.
Pesticides harm living things
Remember that insecticides are designed to kill insects, so honey bees are easy targets. But a poison designed to kill any living thing, including plants, fungus, or molds, can affect your bees. We can’t possibly know all the ramifications, so I think it’s a good idea to do everything you can to protect your colonies. And trust no one.
Honey Bee Suite