Tobacco plants could help save the thinning bumblebee population

Given the health risks tobacco presents to humans, it’s not the first plant you’d consider when trying to lead a healthier lifestyle – yet, according to researchers tobacco could help save the declining population of the bumblebee.

It’s all down to the naturally occurring chemicals found in the flowers of the tobacco plant that can reduce infection levels of a common parasite that infects bees by up to 80 per cent.

The chemical is called anabasine, an alkaloid commonly found in tree tobacco. Insects fed a diet of anabasine were more likely to parasite free after one week.

Researchers at the University of Massachusetts-Amherst in the US said: “One possibility suggested by our results is that bees could self-medicate by consuming plant secondary metabolites when they are infected with parasites,” hypothesising that some nectar compounds could reduce parasite infections in bees.

These findings suggest that growing plants rich in the naturally occurring anabasine around farm fields could create a natural ‘medicine cabinet’, improving the chances that a population of diseased bees will survive and live to pollinate more crops.

The researchers inoculated bees with intestinal parasites, testing the effects of eight naturally occurring nectar chemicals on parasite population growth. The results found that ingesting these chemicals can significantly reduce infection rates by over 80%, reducing the decline of the bee population and prevent the spread of these parasites between and within bee colonies.

Senior Author and Dartmouth Professor Rebecca Irwin said: “Our study was lab-based and so our results need to be interpreted in that light. Nonetheless, we are extending our results from the lab into the field with planned research to assess how planting plants in pollinator strips around agricultural crops will affect bee disease and pollination services to crops.”

Changing agricultural practices have impacted the bumblebee population significantly through removing flowers from the landscape and leaving them with little to feed on. Two species of bee have become extinct in the UK since 1940, with each of the other species showing a steady decline.

The Bumblebee Conservation Trust’s Dr. Richard Comont said: “The honeybee is known to seek out plant secondary metabolites with antifungal properties when exposed to fungus, for example, but this is the first instance in bumblebees as far as I know. It’s a lab study, so hasn’t demonstrated that bumblebees actually seek out the beneficial compounds, but certainly planting the relevant plants more widely would increase bees’ exposure to them.

“Two of the three compounds tested are found in plant species widely grown across Britain, such as nightshades, potatoes and tomatoes, so bees may already be able to self-medicate if desired.”