Insect Decline: The Effects on Nature

Insect Decline: The Effects on Nature

Insects are everywhere – and with more than 1.5 million species, they are the most common living creature on Earth. Despite many people thinking they’re nothing but a pest, they have evolved in their millions for a very good reason.

Insects play a crucial role in our ecosystem – so the news that their population is dwindling dramatically has sparked fears that our entire ecosystem is set to change. The widespread loss of insects would have serious repercussions, as agriculture would suffer and other species would disappear.

According to new research, around 40% of insect species are now in decline. While many people might feel this isn’t important, on the contrary, it will have lasting effects on our planet’s future. Entire ecosystems would collapse without insects and this, in turn, would have detrimental effects on the human race.

Butterfly

© Cathleen Howland / Adobe Stock

 

Latest research

A leading researcher has warned that if the decline of many species of insects isn’t stopped, it will have major repercussions. Francisco Sánchez-Bayo led a study at the University of Sydney in Australia, which was published in the Biological Conservation journal.

The report sent shockwaves through the scientific community when it revealed 40% of our insect species are disappearing. Sánchez-Bayo has warned that if we don’t stop the trend, many of our ecosystems will collapse.

Previous studies have focused on specific areas, but the research carried out in Sydney is the first to tackle the problem on a global level. According to a study by European researchers in 2017, the number of insects in 63 protected areas in Germany has declined by more than 75% since 1990.

Further studies carried out in 2018 by researchers at the National Academy of Sciences revealed that insects and arthropods, such as spiders, had declined by up to 60% in the rainforests of Puerto Rico since the 1970s.

 

Why is this happening?

One of the main causes is habitat change, caused by human activities. These include the conversion of natural habitats into farmland, the draining of wetlands and swamps and increasing deforestation.

Across Europe and North America, small family farms used to play an important role in supporting insects. Their open pastures, hedgerows and places where wildflowers grew were important to the insect population. Now, the agricultural sector increasingly uses chemicals, including pesticides, herbicides and fungicides. Unfortunately, they can kill even the insect species that aren’t being targeted. For example, the insecticide, neonicotinoid, has been blamed in particular for killing bees.

Conservationists say there are between 80 million and 100 million domesticated bee hives worldwide, each containing 10,000 to 60,000 bees, but numbers are dwindling significantly. In August 2018, it was reported one-third of the UK’s bee population had disappeared since 2008.

Research showed 24% of bees across Europe were threatened with extinction. In the United States, the situation is even more serious, with claims that some beekeepers have lost 50% of their hives. This was said to be due to a phenomenon known as Colony Collapse Disorder – most of the worker bees have disappeared, leaving the queen behind.

The scientific community has been unable to pinpoint the cause. A number of reasons have been suggested, such as the presence of Varroa mites, various disease-causing pathogens, loss of habitat and the presence of neonicotinoids.

Bees pollinate around one-third of food crops and 90% of wild plants, providing food for livestock, so the implications of their loss are extremely serious. The effects on biodiversity, the food chain and ultimately the food that reaches our table could be disastrous.

Climate change also plays a role in insect decline, particularly weather extremes that are causing droughts. Other causes include parasites and invasive species.

 

Insects most at risk

As well as bees, some insects are being affected more than others. These include butterflies, moths and other pollinators and insects such as dung beetles, which carry out the crucial task of decomposing waste matter, such as faeces.

Around half of the species of moths and butterflies are in decline and one-third are threatened with extinction. When it comes to beetles and ants, 50% of the species are dwindling

The caddisfly is one insect that’s seriously at risk, with 63% of its species in danger. Researchers say they are particularly vulnerable to pollution, as they lay their eggs in water.

A total of 58 species of insect have been declared extinct in recent years, according to a report compiled by the International Union for the Conservation of Nature in July 2016. These included the Saint Helena earwig, two species of mayfly, Ridley’s stick insect and species of locust and grasshopper. The report also suggested a further 46 insect species were “probably extinct”.

 

Importance of insects

Insects are crucial to the survival of our planet. They are at the bottom of the food chain and are eaten by birds, small mammals and fish. If their numbers decline, there will be no food supply for other creatures, whose numbers will decrease too. This will continue up the food chain and will lead to food shortages for people in the future.

If insects that take care of waste disposal (such as dung beetles) disappear, animal and plant waste won’t be broken down naturally, leading to “unpleasant results”, scientists warn. Without insects, we would also no longer have some of the products they provide, such as honey, beeswax and silk.

Scientists say more research is needed on a global scale into the disappearance of insects, warning that species can vanish very quickly, so we must take action to prevent this before it’s too late.

 

How can people help?

We can protect insects in our own garden by following a number of simple steps. Most importantly, never use chemical insecticides and pesticides, which can have a devastating effect even on the insects you don’t wish to target.

Have a diverse selection of plants in your garden to attract bees and other pollinators, turning it into a mini-meadow. Flowers rich in nectar, such as red clover, bird’s foot trefoil and greater knapweed, are ideal for attracting bees, wasps, moths and butterflies.

For more advice, join a group that promotes environmentally-friendly gardening such as UK charity, Garden Organic. Also, sign up for Buglife’s Get Britain Buzzing campaign, that offers useful advice on wildlife gardening and how to protect our insects.

Check with local retailers on whether their plants are chemically-treated, ask for organic pesticides and always check the labels on products for garden use. By starting small in our own gardens, people’s combined efforts could help reverse the trend and save our insects.

If you enjoy beautiful ornamental gardens, filled with a diverse selection of trees and more than 6,000 plant species, visit Pinetum Gardens.  Follow the Insect Explorer Trail, and marvel the open parkland and tranquil gardens in our 30-acre estate – it’s a wonderful day out for all the family, including the dogs!