So why are so many bees dying? Scientists have tried for years to figure this out. Meanwhile, bees keep dropping like… well, you know. Is it mites? Pesticides? Towers for cell phones? What’s really going on? It turns out that the real problem is much more complicated and widespread than anyone thought. Scientists had difficulty figuring out what caused the so-called Colony Collapse Disorder (CCD), which has killed about 10 million beehives worth $2 billion over the past six years. Pesticides, parasites that carry diseases, and poor nutrition have been suggested as possible causes. But in a first-of-its-kind study published today in the journal PLOS ONE, scientists from the University of Maryland and the US Department of Agriculture found that pollen bees collect to feed their hives is contaminated with a witch’s brew of pesticides and fungicides. The results shed new light on why so many bees are dying, but they don’t tell us what causes colony collapse disorder, when an entire beehive dies at once. Jeffery S. Pettis, Elinor M. Lichtenberg, Michael Andree, Jennie Stitzinger, Robyn Rose, and Dennis vanEngelsdorp, who worked on the PLOS ONE study, got pollen from hives on the east coast, such as those near cranberry and watermelon crops, and fed it to healthy bees.
The bees’ ability to fight off a parasite that causes Colony Collapse Disorder went down significantly. On average, the pollen they ate had nine different pesticides and fungicides, but one pollen sample had 21 other chemicals that could kill them. Also, the researchers found that the parasite was three times more likely to get into bees that ate pollen with fungicides. It turns out that fungicides, which were thought to be safe for bees, are actually a big part of Colony Collapse Disorder. Because of this, farmers may need a whole new set of rules about using fungicides. Neonicotinoids have been linked to the deaths of a lot of bees. This is the same type of chemical that caused a lot of bumble bees to die in Oregon. However, this new study shows that it’s not just one group of pesticides but a mix of many chemicals, making the problem much more complicated. The kinds of chemicals used and how they are sprayed need to be thought about. The bees that the authors studied didn’t eat crops; instead, they almost always ate weeds and wildflowers. This means that bees are more likely to be exposed to pesticides than was previously thought. The writers say, “More attention needs to be paid to how pesticides affect honey bees outside of the field where they are put. We found 35 different pesticides in the pollen we tested. We also found a lot of fungicides. At least one pollen sample had more of the insecticides esfenvalerate and phosmet than their median lethal dose. Fungicides are usually pretty safe for honey bees, but we found that bees that ate pollen with a higher fungicide load were more likely to get Nosema. Our results show that more research needs to be done on the effects of fungicides and other chemicals on bees in agricultural settings that are not fatal. “The main problem is easy to understand: chemicals used on crops kill bees. However, the details of the problem are becoming more complicated. Such as what can be sprayed, where, when, and how to minimize the harm to bees. And other pollinators while still helping crops grow.
Scientists are still trying to figure out how much and by what bees are affected. It will probably be long before solutions are found and put into place. When economics comes into play, it’s impossible to stop spraying anything everywhere. Quartz notes, “The number of bees in the US is so low that it takes 60% of the remaining colonies to pollinate just one crop in California, almonds. And that’s not just a problem on the west coast. California grows 80% of the world’s almonds, a $4 billion market “billion.”