Since the Colony Collapse Disorder epidemic starting in the mid 2000’s researchers have been hard at work determining the contributing factors, we’ve focused on Varroa Mites in the past and thanks to a recent question about all-natural herbicides for fence lines we can explore some of the research in the area of pesticides and herbicides.
On September 5, 2015 the Journal of Economic Entomology published a paper titled “Spray Toxicity and Risk Potential of 42 Commonly Used Formulations of Row Crop Pesticides to Adult Honey Bees (Hymenoptera: Apidae). The study focuses on acute exposure effects on honeybees of the leading pesticides and herbicides, including glyphosate (commonly sold as Roundup). The study concluded that bees aren’t in immediate danger from worst-case-scenario field exposure to glyphosate. Basically, it’s not killing the bees on contact, another study published in Wiley-Blackwell in July of 2014 found no adverse effects on honeybee brood development where the hive’s food sources were all contaminated with glyphosate. This is all good news to beekeepers, but there is still a much bigger conversation about the effects of glyphosate and glyphosate resistant crops on the environment, which we don’t have the time or space to get into here.
While the chemical itself might be safer for bees than many originally assumed there’s still natural alternatives that are cheaper and less controversial, the most commonly used natural alternative is white vinegar, rock or table salt (must be sodium chloride), and a little dish soap. In a mixture of 5 gal vinegar/1 cup salt/1 tbsp dish soap, the higher the concentration of vinegar (5, 10, 20%) the faster it will kill any plants it’s sprayed on.
Having an all natural herbicide is nice but, just like anything, it should be used in moderation. An article on Honeylove.org titled “Herbicides, not Pesticides, Biggest Threat to Bees” explains why. Honeybees forage and pollinate many plants, including many weeds that we regularly kill off for aesthetic or maintenance reasons. So when you have a large fence line covered in weeds, bees see that as a food pantry. The biggest problem regardless of which herbicide you use is the loss of foraging sources for bees, so in order to bee friendly you need to offset the food source you’ve taken away by removing those pesky weeds. Depending on where you live and how much fence line you need to cover there are some great ground cover plants that also serve as food sources for bees while choking out weeds. Plants like Walker’s Low Catmint, or Plumbago that are fairly low maintenance and shouldn’t damage a fence, they are both great sources of nectar for bees, and also help to suppress weed growth, not to mention that they can really brighten up a fence line. With the right planning any fence can be beautiful, well maintained, and bee friendly.
Spray Toxicity study
Evaluating Exposure and Potential Effects on Honeybee Brood study
Honeylove.org Herbicide Article