Insects are the most common of all animals on the planet, totally around 1.5 million types of insects – that’s three times more than any other animal population combined!
They are especially important to all ecosystems because they serve two functions: to pollinate and to clean. Many of the foods we rely on are pollinated by insects, and insects also provide an efficient service in cleaning up decaying matter and decomposing animals.
Insects are also eaten by many species, including reptiles, amphibians, other insects, mammals and, of course, birds, so they are a substantial foundation in the food web that most species simply could not do without.
Since the 1950s, however, insect populations have been declining, and conservationists are particularly concerned about the falling numbers of bees, moths, and butterflies. The Bumblebee Conservation Trust suggests that this decline in bee populations is due to a combination of factors but mostly we look to the loss of wildflowers in the countryside and new agricultural techniques. They estimate that we have lost around 97% of flower-grassland since the 1930s, resulting in the extinction in the UK of two species of bees – so far. They also suggest that:
Through the pollination of many commercial crops such as tomatoes, peas, apples and strawberries, insects are estimated to contribute over £400 million per annum to the UK economy and €14.2 billion per annum to the EU economy.
A very important insect, then. But it’s not just bees that contribute to the UK economy; ladybirds, for example, eat aphids, which feed on farmers’ crops.
But those are the cute, fluffy, colourful bugs – what about the ugly bugs? Cockroaches are probably universally despised, yet the 5,000+ known species that do not inhabit urban areas provide a significant ecological service in forests by cleaning up indigestible leaf matter, and by being a food source to desert lizards and some endangered mammals. Mosquitoes, too, despite being potentially deadly to humans, are a vital food source to birds and mammals.
There are some excellent resources on the internet to learn about the valuable role of insects in all ecosystems: