Tiny radio transmitters track the effect of pesticides on bumblebees
CAMBRIDGE – Researchers are using tiny radio trackers to help understand the movement of local bumblebees.
Amanda Liczner and her team attach radio trackers weighing just 0.13 grams to bumblebee queens to understand the effects of pesticides on bee movements.
Liczner, a postdoctoral researcher at the University of Guelph, is leading the Eastern Bumble Bee study. The queen bumblebee is usually between 17-23mm in length, so it can take the extra weight.
Liczner exposes queens to similar amounts of pesticides that they would come into contact with in nature, through milky sugar water that simulates nectar.
Neonicotinoids are designed to disrupt the nervous system of pests. They are taken up by plants and make the whole plant, including nectar and pollen, toxic to pollinators like bees.
Neonicotinoids disrupt the flight and navigation of bees, reduce taste sensitivity and the ability to learn new tasks. This has a direct impact on the ability of bees to feed themselves. Pesticides also reduce the survival and development of larvae.
As neonicotinoid pesticides become more and more regulated, scientists are testing them against a new class of pesticides that they believe could be seen as an alternative.
Diamides affect muscle function in insect pests. A 2019 study in Nature found that this class of pesticides impacted bees’ ability to move around and, depending on where it was applied to the bee’s body, resulted in death.
“If we find that diamides have less impact, it would make sense to continue phasing out neonicotinoids and perhaps use diamide more frequently, assuming there are no other negative impacts. on other species, ”Liczner explains.
“But if we find that it has more impact than neonicotinoids – and they are internationally known to be bad – then we shouldn’t continue to use diamides. We shouldn’t allow them to be sprayed more often.” , she says.
“So this has important implications for how we will continue to manage our agricultural system and how it might or might not impact our pollinators.”
Radio tracking will determine the impact of the two pesticides on bee movements, and Liczner will look for anything unusual.
The team attaches the trackers with superglue. They first put the bees in a freezer to slow them down. While the bees are still sleepy, the tracker is attached. Trackers were attached to 75 bees for the study of pesticides.
“Once we put the tracker on and the bee wakes up, it’s first unhappy with the tracker,” Liczner explains.
“She tries to get out of it, but then they get to a point where they’re like, ‘OK’ and then they fly away with it.
“It was quite surprising how quickly they just accepted the tracker as a new gem or whatever.”
Bee trackers “slash” the radio towers of the Rare Charitable Research Reserve in Cambridge.
Bumblebees are important pollinators. They are used commercially for greenhouse pollination because of their ability to live in nest boxes inside confined spaces, unlike other bee species.
Bumblebees can perform a unique type of pollination called buzz pollination or sonication. To do this, bumblebees buzz loudly with their wings, and vibrate a flower to dislodge pollen. Plants that produce little or no nectar benefit from this activity, including roses, tomatoes, and cranberries.
Where do bumblebee queens spend their winters?
That’s another question Amanda Liczner, a postdoctoral fellow at the University of Guelph, tries to answer by attaching little radio trackers to bees.
These days, she spends seven or eight hours searching for queens of wild bumblebees in the Cambridge Rare Charity Research Reserve.
Queens in general, but especially new queens, are very important because they are the start of the next generation, Liczner explains. “If all the queens die, then there will be no nests that will start next year.”
The bumblebee’s life cycle begins with a queen awakening from hibernation in the spring and starting a new colony.
“We know a lot about foraging because it is quite easy to find bumblebees on flowers. You just went to a field of flowers and you can find bumblebees. But their hibernation sites and nesting sites are much more cryptic, and we know nothing about them.
“Knowing the overwintering nesting habitat is important because we know habitat loss is a major driver of bumblebee decline,” Liczner explains.
We could be missing important bumblebee habitat needs, she said.
“A lot of people say ‘plant flowers, plant flowers, plant flowers’, but if flowers aren’t the problem and it’s more about wintering and nesting, we’d be wasting money. for conservation, ”Liczner explains. She stresses that flowers are an important part of conservation and that efforts must be stepped up to meet all habitat needs of the species.
So far, Liczner’s team have found 17 queens of wild bumblebees. They aim to find and track 50 in total.