Once a common pollinator across much of the US, the rusty patched bumblebee is in serious decline. So much so that it is listed as critically endangered by the IUCN, and now the US Fish and Wildlife Service are proposing endangered species protection, which would make it the first bee species in history to receive US federal protection. Yet this little bee is not the only one that is experiencing heavy declines.
Across much of the western world, there has been a worrying decline of bees. While the honeybee gets a lot of the media’s attention, largely down to its high-profile status and the tasty honey it produces, it is just one species of around 4,000 that can be found in North America alone. Most of these, for obvious reasons, have not been studied, but it is highly likely that those factors impacting the few that have been, like the rusty patched bumblebee, will also be having a similar effect on the others.
The causes behind the decline in bees, and insect pollinators as a whole, are multiple. A large factor has been the shift towards more industrial agriculture. The countryside used to be a much more varied landscape, a mix of agricultural crops, fallow land, and natural wildflower meadows. This provided a veritable buffet for pollinating insects, giving them a large variety of flowers and plants to feed on for longer periods of the year.
Now, as farming has become more industrialized, including the advances in fertilizers and machinery, the need for leaving patches fallow is no longer necessary as a way to increase soil nutrients. It is thought that in the UK, since the 1930s alone the country has lost over 97 percent of its wildflower meadows. While crop production may have gone up, it has been at a cost to the pollinators.
But farms are not only spraying their crops with fertilizers, they are also covering them in pesticides. This is probably the most obvious, but also highly contentious reason for the bees' decline. Much attention has focused on one particular class of pesticide, known as neonicotinoids. While the manufacturers of neonics, as they are known, maintain that they are at best a negligible harm to bees (though there is now evidence that the companies involved have been covering up their own negative research), the scientific evidence has been building for years that show they have a strong deleterious effect on the insects.
One 18-year study looking at 62 species of bee found that the insects foraging on crops sprayed with the pesticides undergo long-term population declines. This is backed up by other studies that have found those exposed to levels experienced on farms lose direction while out searching for food, confusing the insects so much that they can’t find their way back to the hive. These results led to the European Union putting a moratorium on the use of the chemicals, which they have since extended.
Reversing the worrying trend is going to take multiple measures, including encouraging farmers to leave patches for wildlife, as well as limiting the use of harmful pesticides. Let’s just hope we can do it in time, before we lose more species like the rusty patched bumblebee.