Bees are dropping dead in Brazil and sending a message to humans

Image of tractor spraying pesticides.

(Bloomberg) Around half a billion bees died in four of Brazil’s southern states in the year’s first months. The die-off highlights questions about the ocean of pesticides used in the country’s agriculture and whether chemicals are washing through the human food supply — even as the government considers permitting more. Most dead bees showed traces of Fipronil, a insecticide proscribed in the European Union and classified as a possible human carcinogen by the U.S. Environmental Protection Agency.

Pesticide widely used in US particularly harmful to bees, study finds

Image of honey bees.

(The Guardian) Agriculture in the United States has become 48 times more toxic to insects over the last 25 years, largely due to neonicotinoid pesticides, according to the study. “We have not learned our lessons… There’s this fundamental recklessness and foolishness to introducing [neonics] and continuing down this path,” says Kendra Klein, an author of the study and a senior scientist at not-for-profit Friends of the Earth. The study can be found here.

Adjuvants amplify the toxicity of pesticides on honey bees

Image of researcher among yellow flowers.

(EurekAlert/Society of Environmental Toxicology and Chemistry) When applied alone, adjuvants – chemicals commonly added to pesticides to help them spread, adhere to targets, disperse appropriately, prevent drift and so on – caused no significant, immediate toxicity to honeybees. However, when the pesticide acetamiprid was mixed with adjuvants and applied to honeybees in the laboratory, the toxicity was quite significant and immediate: the mortality was significantly higher than for control groups. Additionally, flight intensity, colony intensity and pupae development continued to deteriorate long after the application comparative to the control groups.

Research reveals how bee-friendly limonoids are made

Image of leaf cluster.

(John Innes Centre) The best known limonoid, azadirachtin, is famous for being bee-friendly yet having a strong anti-insect effect. Due to the complex chemical structure of limonoids, it is difficult to chemically synthesize these natural products. As a result, their use is currently limited to what can be extracted from plant materials. “If this engineering could be achieved, then crops could be developed with an inherent resistance to insects, which could reduce reliance on chemical application for crop protection.”

Plant probe could help estimate bee exposure to neonicotinoid insecticides

Diagram of new probe process.

(EurekAlert/American Chemical Society) Neonicotinoid pesticides continue to be investigated because of their suspected role as a contributing factor in declining bee populations. However, limitations in sampling and analytical techniques have prevented a full understanding of the connection. Now researchers have developed a new type of probe that helps to quantify neonicotinoids in plants and study their movement and distribution throughout the plants over time.