Neonicotinoids killing bees, new research

This 2015 video is called How Neonicotinoids Kill Bees.

Bee populations are declining, and neonicotinoid pesticides continue to be investigated — and in some cases banned — because of their suspected role as a contributing factor. However, limitations in sampling and analytical techniques have prevented a full understanding of the connection. Now, researchers describe in the ACS journal Environmental Science & Technology a new approach to sample neonicotinoids and other pesticides in plants, which could explain how bees are exposed to the substances: here.

From the University of Exeter in England, 17 July 2019:

More “intensive” beekeeping does not raise the risk of diseases that harm or kill the insects, new research suggests.

Intensive agriculture — where animals or plants are kept crowded together in very high densities — is thought to result in higher rates of disease spreading.

But researchers from the University of Exeter and the University of California, Berkeley found this is not the case for honeybees.

Their study modelled the spread of multiple honeybee diseases and found that crowding many colonies together was “unlikely to greatly increase disease prevalence.”

However, the research only applies to existing honeybee diseases — and the findings suggest intensive beekeeping could accelerate the spread of new diseases.

“Crowding of animals or crops — or people — into minimal space usually increases rates of disease spread,” said Lewis Bartlett, of the University of Exeter and Emory University.

“We carried out this study because beekeepers were worried about this — especially given the many threats currently causing the decline of bees.

“To our surprise, our results show it’s very unlikely that crowding of honeybees meaningfully aids the spread of diseases that significantly harm honeybees.

“Honeybees live in close proximity to each other naturally, and our models show that adding more bees does little to raise disease risk.

“So, beekeepers don’t need to worry about how many bees they keep together as long as there is enough food for them.

“The key is not whether they encounter a disease — it’s whether they are fit and healthy enough to fight it off.”

Although the paper says intensification of beekeeping does not boost diseases among honeybees, Bartlett points out that intensive agriculture — especially use of pesticides and destruction of habitats — harms bee species including honeybees.

The research was partly funded by the Biotechnology and Biological Sciences Research Council and the National Institutes of Health.

During the past 20 years, insecticides applied to U.S. agricultural landscapes have become significantly more toxic — over 120-fold in some midwestern states — to honey bees when ingested, according to a team of researchers, who identified rising neonicotinoid seed treatments in corn and soy as the primary driver of this change. The study is the first to characterize the geographic patterns of insecticide toxicity to bees and reveal specific areas of the country where mitigation and conservation efforts could be focused: here.

Alarming Long-Term Effects of Insecticides Weaken Ant Colonies. July 1, 2020 — Scientists have shown how even low doses of neonicotinoid insecticides, as they may realistically occur in contaminated soils, adversely affect the development of black garden ants (Lasius niger): here.