We often view insects as pests, invading our picnics or homes and sometimes even stinging us. But their ecological importance, although often overlooked, is vast.
Insects are the most common animal on the planet, with 1.5 million species identified. They are the reason that humanity is sustained as we know it – they pollinate many of the flowers, fruits and vegetables that we eat. As well as this, they form the bottom part of the food chain. This means they are the sole food source for many animals.
Let’s start with the basics.
What is insect pollination?
Insect pollination is the act of pollen being transferred from one flower to another by an insect. The pollen sticks to the insect’s body, and when it moves between flowers the pollen transfers from the male parts of the flower to the female parts. This fertilises the plant, allowing it to develop fruit and seeds that will grow into a new plant. Insects are responsible for the pollination of about 80% of trees and bushes globally.
It’s not just the eye-catching insects that are doing all the work…
Bees already get the credit for being pollinators that are fundamental to life as we know it. But, honeybees aren’t the only insects working hard – in the UK alone, at least 1,500 insect species are pollinators. So what other insects are doing incredible work?
Hoverflies are known to visit at least 72% of global food crops. They pollinate a wide variety of fruit crops, such as apples, pears, apricots and strawberries. Hoverflies have the ability to travel hundreds of kilometres a day, carrying pollen over great distances including over open water. This means they are able to fertilise plants in climates that are unsuitable for bees. As a result, hoverflies can reach more isolated areas than bees.
Beetles are prehistoric pollinators and have been visiting flowering plants since before dinosaurs evolved! They’ve been pollinators for at least 50 million years longer than bees. Because beetles were around earlier than bees, they’re important pollinators of ancient plants such as magnolias and water lilies.
Around 1,000 species of beetles in the UK pollinate plants; the flower, longhorn, soldier, sap and scarab beetles to name a few. They are attracted to fragrant plants, as well as clusters of flowers such as sunflowers.They primarily visit open, bowl-shaped flowers that they can easily access.
Moths can be incredibly irritating, especially on summer nights when we leave windows open and they flutter around light bulbs. However, they deserve recognition for being excellent pollinators, specifically working during the night. Similarly to hoverflies, moths travel over long distances. This allows for more mixing between plant populations than bees are capable of.
In a recent study, pollen grains from agricultural crops such as peas, soybean and oil-seed rape were found on moths. In total, pollen from 33 species of plants were detected on moths.
Midges are a type of very small fly. They are the primary pollinators of the intricate flowers on cocoa trees, allowing the trees to produce fruit. Due to the small size of the flowers, midges are seemingly the only creature that can pollinate them. They have a bad reputation due to their ability to sting, but without them there would be no chocolate!
Insects as natural predators
What’s more, insects aren’t just pollinators, they are also a useful natural alternative to pesticides – a huge win for organic farming. The use of pesticides to remove crop-eating insects kills all insects that come into contact with the chemicals, rather than just the target species.
A natural and organic alternative is using predatory insects as pest controllers. This would help to prevent pest outbreaks and reduce the use of pesticides. It would also stop non-target species of insects being removed from plants.
What insects can be used as pest controllers?
Aphid’s are small insects that suck nutrients from plants and can be devastating for food production. Hoverflies are a great natural pest controller – about 40% of them produce larvae that prey on these small crop-eating insects. Wasps also hunt many of the insects that feed on crops, and their larvae eat aphids and other pests. Ladybirds lay hundreds of eggs that eat up to 5,000 aphids once they hatch.
Insects are in trouble
Many insects are facing extinction, which would be devastating for life on Earth. The main issues threatening insects are habitat loss and pesticide use. As a result, it’s suggested that 41% of insects are facing extinction within the UK. Without insects, ecosystems would collapse. Our crops would not be pollinated, and both humans and livestock would face catastrophic food shortages.
Restoring wildflower meadows lost to land-use changes in recent decades would support native pollinating insects, providing them with a habitat to thrive in. Another solution is reducing our reliance on pesticides. Putting away the spray and shifting to organic farming would stop the decline of thousands of insects.
- Support Buglife’s work on social media and sign up to their newsletter. If you can, become a member for as little as £3 a month.
- Download the Wildlife Trusts free guide on how you can help insects recover where you live.
- Read these two reports by the Wildlife Trusts: Insect Declines and Why They Matter, and Reversing the Decline of Insects.
- Read more about insects and pollinators in these articles from the Curious archives: