Consider American biologist Edward Osborn Wilson’s words, “If we were to wipe out insects alone on this planet, the rest of life and humanity with it would mostly disappear from the land,” in light of the following fact:
The rapidity of the decline is estimated at a 2.5% per year and this rate of extinction is eight times faster than that of mammals, reptiles and birds. This suggests that insects could vanish from the planet within a century. And all forms of life, as warned by Wilson, will follow suit.
The Windshield Phenomenon
Insects, particularly their numbers, haven’t received the kind of academic focus they deserve. So common and abundant were they that we often took them for granted. No wonder then, they became conspicuous only by their absence. People began to notice hordes go missing from parks, canals or even from under the streetlights.
Since their decline was more anecdotal than documented, scientists developed shorthand for it, calling it the windshield phenomenon. The term refers to people’s perception of fewer insects smashed across their car’s windscreens than they used to see even a decade ago.
It’s strange that bugs, the wildlife we come in contact with on a regular basis – ants in the garden, spiders behind the curtain or little weevils in the rice bag – are the ones we have paid the least attention to. The lack of data from the past has become a major hurdle for entomologists to assess the disappearance of insect species and this serves as reminder of how little we understand of the world we inhabit.
Reasons for the Decline
Several reports, carried out mainly in Western Europe and the US, have attributed the plummeting numbers to intensive industrial farming, untamed use of pesticides and chemical fertilizers, and urbanization. In the UK, where insects are most studied in the world, 23 bee and wasp species were wiped out just in the last century. This corresponds with the doubling of pesticide application in the last 25 years.
New classes of insecticides such as neonicotinoids and fipronil — which were introduced in the last 20 years — have further sterilized the soil and killed grubs. The damage caused by these insecticides persists in the environment and effects have been recorded in nature reserves — 75% of insect loss, in Germany for example, occurred in protected areas.
The onslaught of climate change, continuous habitat loss and deforestation are making it increasingly difficult for insects, the most varied and abundant animals on the planet (they outweigh humans by 17 times!), to survive.
One of the strongest impacts of insect loss is felt by those for whom they are a vital food source – birds, reptiles, amphibians and fish. Butterflies and moths, the study states, are the worst hit. The number of butterfly species shrunk by 58% on farms in England between 2000 and 2009.
These cascading effects have acutely hit honeybees as well. In the US, honeybee colonies have dropped from 6 million in 1947 to a mere 2.5 million in 2014. What’s even more shocking is that between October 2018 and April 2019, US lost 40% of its honeybee colonies.
A similar story has panned out in the UK, where a third of 353 wild bee and hoverfly species experienced declines between 1980 and 2013.
This has profound consequences for agriculture. Three out of four fruit or seed-producing crops, across the globe, are dependent, at least in part, on pollinators. Pollinators affect 35% of global agricultural land thereby supporting the production of 87 main food crops in the world. Furthermore, natural pollination supports crop production. Without these vital pollinators, which form the base of food webs, our food would suffer in both quality and prices.
What Can You Do
Conservationist have argued that the decrease in insect biomass can be countered by setting firm targets to reduce pesticide use and rewilding public parks and gardens. The report sees potential for insect-friendly habitats in urban spaces.
This idea trickles into the domestic sphere as well and we can all act as “first responders”. Some of these measures can be undertaken by all of us:
- Diversify your garden. Different nectar and pollen will attract a variety of insects thereby creating a healthy ecosystem that will in turn benefit the birds, mammals and amphibians.
- Allow your garden to flower and mow it less frequently.
- Grow plants that attract pollinators such as lavender, catmint or buddleia. Even weeds, such as dandelions, attract bees and can be allowed to grow in the yard. Further, you can grow specific plants for insects or pollinators that you know are under threat in your region. For example, paw paw trees are the only host plant for zebra swallowtail butterflies.
- Invest in a bee hotel or just leave a log or brush pile in your garden for insects such as woodlice (which recycle nutrients and are food for birds and small mammals).
- Plant in vertical layers and plant native species, as they are most effective at attracting pollinators.
- Border your plants is a great way to improve pollination and support bees when plants stop blooming. It further attracts and supports other pollinators such as wasps and hoverflies and these, in turn, control pests.
- Act as informed citizens and urge local authorities to plant native trees that flower in public parks and wildflowers in road medians.
- Encourage local authorities to not use pesticides.