Question: Why is there a decline in the number of bees in the world? Does this differ between continents? Thank you.

John Paterson answered on 17 Jun 2019:

Good question! As Emma said, we are currently experiencing a huge decline of all types of insects worldwide and bees are certainly one of the types of insects that are declining. We have a good idea of exactly how this decline is happening across Europe and the USA, which is where the 40% decline figure comes from, but we don’t have a good idea for lots of other continents so there is still a lot of research to be done.

There are lots of reasons for decline, but we can pick out three main ones. First is the loss of habitat as more and more of the natural world gets converted either to farmland or to towns and cities. This means that bees lose both places to live and places where flowers would have grown. So they lose both homes and food. This isn’t true of all bees – some bee species actually have more places to live in cities, like mason bees – but for most bee species cities and farms are a bad thing. You might think farms might be good for bees but generally they’re bad because of the next two reasons – insecticides and farming methods. Insecticides are used in most kinds of farming to protect crops and increase the amount of food grown. Generally, insecticides aren’t meant to hurt helpful insects like bees but they still do. Research has shown that even tiny amount of insecticides can make bees sick and confuse them, meaning they collect less food and sometimes can’t get back to their hive. The insecticide also builds up in the honey and pollen they collect to feed to their young back at the nest, so it harms the growth of new bees. Farming methods have also changed in modern times. Because of the pressure put on farmers to grow lots of food and the fact that they often don’t get much money for it, farmers need to be very efficient with their farming. The best way to do this is to create fields called monocultures – fields where only one type of plant is grown. This is bad for bees because if only one type of plant is grown it flowers only once or twice a year, but bees need lots of different flowers coming out at different times of year. It also means that there is less variety in the landscape of the fields, which means fewer places where bees can live.

There are lots of other reasons why bees and insects are declining but those are the three big ones. People often focus a lot on honey bees when we talk about bees declining, but it is worth pointing out that honey bees are actually a farmed species of bee and not a wild species. They are the bee equivalent of sheep or cows. Honey bees are important pollinators as well but it is the wild species like bumblebees that are at greatest risk.

The good news is there are lots of ways people can help, particularly if you have a garden. You can put up insect hotels for solitary bees and you can plant flowers like lavender, cat mint and cotoneaster so the bees have lots of food. Even letting the grass in your lawn grow a bit longer (10-15cm) can allow flowers like clover or self-heal to grow, which bees love. A recent bit of research identified gardens as one of the best and fastest-growing new habitats for bees and insect life, so if we can make good use of them we can really help the bees.