“There are agricultural pesticides everywhere,” she said. “They accumulate in the wax of bee hives, so bees in particular are exposed. And their habit of foraging very broadly across a staggering diversity of plant species also tends to expose them to many different types of habitats, which may also have different types of chemical residues.”
Other chemicals are applied directly to the hives, she said. For the past 20 years, beekeepers have used acaricides – chemicals designed to kill mites but not bees – in the hive.
While evidence so far does not support the idea that exposure to synthetic pesticides is a cause or significant contributor to colony collapse disorder, the massive die-off of honey bees first reported in late 2006, “it’s abundantly clear that pesticides aren’t really very good for any insect,” Berenbaum said. “So we figured it was about time somebody knew something about how pollinators process toxins.”
The researchers focused on cytochrome P450s, enzymes that are well-known agents of detoxification “in most air-breathing organisms,” Berenbaum said. Other studies had shown that cytochrome P450s in honey bees play a key role in their tolerance of pyrethroid pesticides, such as tau-fluvalinate, which is used to kill mites in the hive. But no previous study had identified specific cytochrome P450s in bees or in other pollinating insects that contribute to pyrethroid tolerance, Berenbaum said.
In a series of experiments, the team identified three cytochrome P450s in the honey bee midgut that metabolize tau-fluvalinate. They discovered that these enzymes also detoxify coumaphos, a structurally different organophosphate pesticide that also is used to kill mites in bee hives.
The evidence also suggests that honey bees were “pre-adapted” to detoxify pyrethroid pesticides, Berenbaum said. Pyrethroids are similar in structure to naturally occurring defensive compounds, called pyrethrins, produced by some flowering plants. Honey bees have likely had a long history of contact with pyrethrins, which are found even in some flowers in the daisy family. It appears that the same enzymes that helped the honey bees detoxify the pyrethrins in nature may also help them tolerate this relatively new pesticide exposure.
The new findings should enhance efforts to develop mite control methods that are even less toxic to bees, Berenbaum said.
Also on the study team were U. of I. cell and developmental biology professor Mary Schuler and postdoctoral researcher Wenfu Mao.Editor’s notes: To reach May Berenbaum,
Diana Yates | University of Illinois
How much drought can a forest take?
20.01.2017 | University of California - Davis
Plasma-zapping process could yield trans fat-free soybean oil product
02.12.2016 | Purdue University
For the first time ever, a cloud of ultra-cold atoms has been successfully created in space on board of a sounding rocket. The MAIUS mission demonstrates that quantum optical sensors can be operated even in harsh environments like space – a prerequi-site for finding answers to the most challenging questions of fundamental physics and an important innovation driver for everyday applications.
According to Albert Einstein's Equivalence Principle, all bodies are accelerated at the same rate by the Earth's gravity, regardless of their properties. This...
An important step towards a completely new experimental access to quantum physics has been made at University of Konstanz. The team of scientists headed by...
Yersiniae cause severe intestinal infections. Studies using Yersinia pseudotuberculosis as a model organism aim to elucidate the infection mechanisms of these...
Researchers from the University of Hamburg in Germany, in collaboration with colleagues from the University of Aarhus in Denmark, have synthesized a new superconducting material by growing a few layers of an antiferromagnetic transition-metal chalcogenide on a bismuth-based topological insulator, both being non-superconducting materials.
While superconductivity and magnetism are generally believed to be mutually exclusive, surprisingly, in this new material, superconducting correlations...
Laser-driving of semimetals allows creating novel quasiparticle states within condensed matter systems and switching between different states on ultrafast time scales
Studying properties of fundamental particles in condensed matter systems is a promising approach to quantum field theory. Quasiparticles offer the opportunity...
19.01.2017 | Event News
10.01.2017 | Event News
09.01.2017 | Event News
23.01.2017 | Health and Medicine
23.01.2017 | Physics and Astronomy
23.01.2017 | Process Engineering