Wild ground-nesting bees might be exposed to lethal levels of neonics in soil

Date: August 26, 2019

Source: University of Guelph

In a first-ever study investigating the risk of neonicotinoid insecticides to ground-nesting bees, University of Guelph researchers have discovered at least one species is being exposed to lethal levels of the chemicals in the soil.

Examining the presence of these commonly used pesticides in soil is important given the majority of bee species in Canada make their nests in the ground.

This study focused on hoary squash bees, which feed almost exclusively on the nectar and pollen of squash, pumpkin and gourd flowers.

Researchers found that the likelihood that squash bees are being chronically exposed to lethal doses of a key neonicotinoid, clothianidin, in soil was 36 per cent or higher in squash fields.

That means 36 per cent of the population is probably encountering lethal doses, which is well above the acceptable threshold of 5 per cent, in which 95 per cent of the bees would survive exposure.

"These findings are applicable to many other wild bee species in Canada that nest on or near farms," said U of G School of Environmental Sciences professor, Nigel Raine, who holds the Rebanks Family Chair in Pollinator Conservation and worked on the study with PhD student and lead author Susan Chan.

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Antarctic biodiversity hotspots exist wherever penguins and seals poop

Date:  May 9, 2019

Source:  Cell Press

Scientists have found that on the desolate Antarctic peninsula, nitrogen-rich poop from colonies of penguins and seals enriches the soil so well that it helps create biodiversity hotspots throughout the region. Their work, appearing May 9 in the journal Current Biology, finds that the influence of this excrement can extend more than 1,000 meters beyond the colony.

Researchers braved the wicked cold of the Antarctic and maneuvered through fields of animal waste and groups of clamoring elephant seals, gentoo, chinstrap, and Adélie penguins to examine the soils and plants surrounding these colonies. "What we see is that the poo produced by seals and penguins partly evaporates as ammonia," says Stef Bokhorst, a researcher in the Department of Ecological Sciences at Vrije Universiteit Amsterdam. "Then, the ammonia gets picked up by the wind and is blown inland, and this makes its way into the soil and provides the nitrogen that primary producers need in order to survive in this landscape."

In fact, this process allows ammonia to enrich an area up to 240 times the size of the colony. And the results of this enrichment: a thriving community of mosses and lichens, which in turn supports an incredible number of small invertebrates, like springtails and mites. "You can find millions of them per square meter here, but in grasslands in the US or Europe, there are only about 50,000 to 100,000 per square meter," says Bokhorst. "It took months and months of sitting in the lab counting and IDing them under a microscope," he says, and he notes that trekking through the bitter temperatures of the Antarctic was far preferable to that task.

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