Bumblebees are adapting to climate change, but remain in serious danger

26 august 2020,

Bumblebees can help plants flower more quickly. However, pesticides, parasites and climate change are putting this key species in serious danger.

Bumblebees are funny little animals. They look chubby, almost soft. We’re less afraid of them than bees because we know they rarely sting us. Bumblebees, part of the Bombus genus, are pollinating insects that perform a vital function, and essential crops we human beings feed on – from tomatoes and potatoes to strawberries and blueberries – depend on these insects’ activity.

Bumblebees’ secret to collecting more pollen

A team of entomologists, i.e. scientists who study insects, from France and Switzerland have discovered an interesting fact. When pollen is scarce, bumblebees nibble plant leaves to accelerate the production of flowers. This trick is especially useful now that climate change has changed seasonal patterns, making life very difficult for these insects. Sometimes, early thawing causes plants to flower while bumblebees are still hibernating. By the time the soil heats up, which signals to the insects that it’s time to come out of hibernation, there are very few flowers left. Conversely, sometimes bumblebees emerge from hibernation before plants have begun to flower and are therefore at risk of starvation.

Why are bumblebees endangered?

These problems are among the factors threatening these precious insects with extinction in Western countries. In addition to global warming, bumblebees are threatened by habitat loss due to the expansion of cultivated areas, the use of pesticides and the increasingly widespread presence of pathogens. These are the finding of a study conducted at the University of Wyoming in the United States, whose results were published in the scientific journal Ecosphere. Researchers spent the last three years exploring the causes of this species’ decline. Lusha Tronstad, a zoologist at the Wyoming Natural Diversity Database, states that the likelihood of encountering a bumblebee in the United States decreased by 93 per cent between 1998 and 2018.

The researchers’ goal is to convince the government to increase protections for bumblebees in accordance with the Endangered Species Act. Furthermore, according to Tronstad, there’s a lot that people with land can do too. For example, it’s important to choose plants and flowers that bloom in the summer and produce pollen; additionally, a water source has to be secured for the animals, as well as a nesting and overwintering habitat in the ground, where they usually nest. It’s also important to make sure not to work these areas until bumblebees come out of hibernation.

The EU should do more to protect pollinating insects

Greater commitment is also required on the part of the European Union according to the Court of Auditors, whose report finds evidence that Brussels hasn’t provided adequate protection to pollinating insects. Member states have been allowed to keep using dangerous pesticides and, in some cases, extraordinary licences have been granted for the use of the notorious neonicotinoid pesticides, banned in 2018. However, almost 80 per cent of European crops depend on these insects, whose annual contribution to agriculture in the EU is estimated to be worth 15 billion euros.

We can all help bees and bumblebees too by brightening our gardens and balconies with many colourful and, most importantly, pollen-producing flowers.

Translated by Patrick Bracelli