Science was not giving us an extraordinary amount of good news these days. We're hurrying to climate catastrophe for one. We have wronged the environment so badly, it's hard to call it even an environment. And we turn to bite (or yell): Bee populations, which we rely on to pollinate our crops, decrease.
Still, science comes to rescue by sticking QR codes to the back of their shoulders and tracking their movements with a robotic camera. Researchers have created a system that tracks individual bees, as well as the dynamics of whole colonies, exposed to imidacloprid, a neurotoxin belonging to the infamous group of pesticide neonicotinoids. The findings are not nice, but they can go a long way in trying to destroy how neonicotinoids are devastating bees, and how can we save these flyers.
Neonicotinoids are the most common class of insecticides worldwide. "When we began to use them in agriculture in particular, they passed the initial test," Oh, are they sure about the bees at the concentrations they might encounter in this area? ", Says Harvard biologist, James Crall, paper in Science describing the technique of tracking bumble bees.
But those tests were not enough. "You may not see a dead bee in 24 or 48 hours, but you still see important changes in behavior over time, which leads to a diminution in function and long-term colony growth," adds Crall.
Even if a neonicotinoid like imidacloprid, a common insecticide, does not completely kill a bee, it can cause other changes to it. Previous studies have demonstrated, for example, that in the field of neonicotinoids the ability of bees to navigate and to find flowers can be affected. This has implications for how bees feed themselves and their colonies in general. What happened interior a colony exposed to neonicotinoids, however, was more difficult to analyze.
There's the research of Crall and his team. In the lab, they set up a dozen bumble-bee colonies each housed in a clear acrylic box. The researchers fed some imidacloprid colonies at levels equal to what bees would be exposed to the field, while retaining other control colonies without imidacloprid. A system of robotic cameras moves around the tracks above the head, perifestating in each nest below. "So, we monitor for 5 minutes what happens in each colony 12 times a day," says Crall. "And we can run this completely autonomous for almost two weeks." Because each bee has a QR code on its back, a computer vision system can track its day and night movements.
The differences that the researchers found between exposed and normal colonies are striking. "Bees are less active, so they spend more time resting," says Crall. "I'm a little farther from the nesting center, where larvae call for care," and they also interact less with cemeteries. " Behavioral changes are more pronounced at night. "Sometimes the eye colony appears fully functional during the day and then you see these powerful accidents overnight."
Low levels of activity are particularly problematic when you think that the bumblebees have those larvae to wander. Healthy bees will actively warm young people with their bodies vibrating their muscles. What Crall and colleagues have discovered is that colonies exposed to imidacloprid are not as good at maintaining larval temperature as normal bumble bees, which could have implications for young people's development.
If this is one of the main ways these compounds affect growth, it could be more extreme in some environments than others or under different conditions than others, "says Crall. If the outdoor temperature is great for bumblebees, it would not it could be a big business, but if you have temperature changes and imidacloprid affects the ability of individuals to control the nest climate, young people can not thrive.
This was not the only difference in how bees feed their nausea. Typically, bumblers build a wax canopy that sits like a blanket on the top of the chick in development, again for heat. Almost all control colonies experienced by Crall did this, but none of the colonies exposed to imidacloprid did. "It is possible to destroy not only these short-term direct behaviors, but these long-term changes in nest architecture," says Crall.
Most bee species, however, are solitary, not social. So, what happens to solitary bees exposed to neonicotinoids? Females are largely on their own in these species: they will mate with a man, and the man will come out. "Then the woman has to do all these different activities of nesting, feeding, laying eggs and continuing that cycle for a few weeks or months to death," says Nigel Raine, University of Guelph, who studies bees and exposure to pesticides and who wrote a comment on this new study. Therefore, we could imagine that exposure to pesticides for that individual could have more serious consequences for their reproductive production.
At the other end of the spectrum are honeybees, whose colonies are among the thousands. (The species that Crall studies drops in the middle: wool Bombus impatienswith about 200 colonies.) Neonicotinoids cause subtle behavioral changes for honey bees, but this could not be as consistent as a small bee colon or a solitary bee. "A relatively small impact on an individual's feeding performance can be masked by more individuals going out and doing that task," says Raine.
Good news for honeybees, but here's a problem. Researchers and regulators have relied heavily on honeybees as a model for studying neonicotinoid exposure – they are easy to find for one. But when it comes to pesticides, what happens to honeybees probably does not go for bumbles or solitary bees due to the size of the societies. Raine says she works with colleagues and regulators to consider these potentially more vulnerable species.
We are also talking about a single stress factor here: Crall and his colleagues analyzed only one pesticide of seven neonicotinoids. But the idea is that researchers can use this technique to test other pesticides in bee colonies.
Bees are in difficulty, yes. But with new techniques such as this, scientists better understand what threatens them. A little good news probably on a foolish planet.
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