What have insects ever done for us?

 

Sexton beetle - © Richard Burkmar

The UK has over 20,000 species of insect, but their numbers are declining sharply. As we gear up to take ‘Action for Insects’, science communicator David Urry looks at why we should care.

The drastic decline of insects we have witnessed over the last 100 years affects us all. Some people may not like insects, others may barely even notice them, but we cannot afford to ignore them any longer.

The main reason we must take action for insects is purely selfish: it is taking action for ourselves and protecting our future.

If you need further convincing of the value of insects, here are some answers to the question: ‘What have insects ever done for us?’

Pollination

There are a number of ways that plant species go about the important business of pollination, an act essential for reproduction in most plants. They can use the wind, or direct contact with flowers, but perhaps the niftiest way is to use a willing insect courier, duly rewarded with a shot of sweet nectar.

Around 80% of UK plants are pollinated by insects, including a large number of our crops. It has been estimated that the value of insect-pollinated fruits and vegetables grown in the UK is about £220m a year.

It is clear that we need insect pollinators, but it is also clear that they need some help from us.

Early Bumblebee, Jon Hawkins - Surrey Hills Photography

Early Bumblebee, © Jon Hawkins - Surrey Hills Photography

Decomposers

Many insects love mess, or more specifically, getting stuck in and clearing it up. One of the important and unnoticed roles that insects play is to break down and decompose organic matter.

Insects that carry out this role are collectively referred to as saprophages (from the Greek words ‘sapros’ meaning rotten and ‘phagein’ meaning to eat). They feed on dead plant tissues, dead animals, and the excrement of other animals.

They may not have the most glamorous of roles, but our decomposers are unsung heroes of recycling, turning dead organic matter and waste back into usable forms. We perhaps owe more to these insects than any other group.

Their actions help give us healthy, fertile soil. From this we get flood protection, defence against climate change, the food we eat and other plant-based resources, and not to mention all the vegetation that forms the basis of the countryside we enjoy, rely upon, and call our home.

All of this we get for free, so long as we keep the soil alive of course. Not a bad deal really. 

Biological control

Life can be full of hurt as an invertebrate. All insects are susceptible to being eaten by either another insect or something bigger. It is an insect-eat-insect world out there, but this can be of real use to humans too. Biological control of pests is big business, estimated to be worth $4.5bn a year in the USA alone.

The conservation of natural enemies is probably the most important biological control practice available to growers and means that the use of damaging chemical pesticides can be avoided.

A total of around 16.9 thousand tons of toxins are released as pesticides onto the land throughout the UK each year, yet there is an alternative – insects!

Insect predators and parasitoids have perfected their merciless seek and destroy skills over millions of years - they just need a bit of support! This is also backed up by research, which suggests that biological control can be highly effective, and also likely to save farmers money.

Food for animals

We may not look at insects and instantly lick our lips, but for many animal species, insects constitute the majority of their diet. Insects are often at the bottom of the food chain, so if they were removed, this would cause ecosystems to collapse.

Numerous UK birds, mammals and fish are insectivorous, including all 17 of our native bat species. There is also great potential to use farmed insects as a sustainable source of feed for livestock, pets and in fish farms.

The decline of insects is essentially starving our countryside, slowly taking away the food sources which many animals have fed upon for millions of years. We are already witnessing this loss, with the declines in many of our bird populations, such as the disappearance of the red-backed shrike, and worrying declines in other species, such as spotted flycatchers, cuckoos and nightingales.

Pied wagtail collecting food for chicks

Pied wagtail collecting food for chicks , © Tom Hibbert

Food for humans

I don’t like crickets, I love them – especially with a sweet and sour dip. And I am not alone. Around two billion people eat insects as part of their regular diet, and 80% of countries around the world consider insects as a ‘normal’ source of food. And with good reason: they are packed full of protein, vitamins and minerals.

Insects can be sustainably farmed, and if you know what you are doing they can be absolutely delicious. Encouraging people to eat insects may seem at odds with a campaign to combat their decline, and we are certainly not suggesting the widespread harvesting of insects from the wild. Instead, insect farms can be a sustainable and efficient means of producing tasty protein. The idea is now less pie in the sky and more fly in a pie!

Environmental indicators

Many insect species are highly susceptible to changes in the environment. This sadly makes them vulnerable to habitat degradation and climate change, but it also makes them very useful as bio-indicators. By carefully monitoring changes in insect populations, ecologists can measure the impact of disturbance and take steps to mitigate changes that may not have been initially apparent within other species.

Butterflies are recognised as valuable environmental indicators, and representatives for the diversity and responses of other wildlife. Many aquatic invertebrates, such as caddisflies, are also important indicators of the quality of our waterways.

Key to insects continued value as environmental indicators is our continued monitoring, research and understanding of them. Insects have much to tell us about our impact on the planet, but if no one is paying attention, these clues will be missed.

Common blue

Common Blue , © Paul Thrush

What can you do for insects?

The facts are startling: insects are dying out up to eight times faster than larger animals and 41% of insect species now face extinction. 

But it's not too late to stop and reverse this loss of insect life.

From April, you can download your own guide to taking #ActionForInsects from The Wildlife Trusts. Make your pledge today. Backed by a major scientific report, the campaign maps out the road to insect recovery with practical actions that we can all take.

Share your actions on social media with #ActionForInsects and encourage your family and friends to get involved at home too!