Insect decline – Over a quarter of insects lost in last 30 years

Earth has lost over a quarter of its insect population in 30 years with insects disappearing at a rate of 9% per decade researchers say. A study of global insect decline published in the journal, Science, says there is much variation from place to place but lead author Roel van Klink of the German Centre for Integrative Biology describes the findings as “awfully alarming”.

Worst affected areas are North America, in particular the Midwestern United States and parts of Europe. Data appeared to show the decline leveling off with the Midwestern belt losing a shocking 4% of its insects a year. Mr. Van Klink said the most severe losses seem to be around urban, suburban and cropland areas where insects are losing their food and habitat year on year. The study found a 27% decline in insect numbers in the last 30 years.

Ladybirds facing catastrophic decline in numbers
Ladybirds facing catastrophic decline in numbers

The study compiled data from 166 long-term surveys across 1676 sites distributed across the world. In a sliver of good news, they found that freshwater insect populations had increased by 11% per decade, perhaps owing to better clean water technology and climate change. Local scale factors were very much a driving force behind changes in population trends worldwide. However, it is worth noting that freshwater insects comprise a tiny percentage of the insect numbers in the world.

Previous research has indicated that insect decline is driven by a loss of habitat due to increased urbanisation as well as farming practices that remove weeds and flowers that many of the insects thrive on.

A study in February 2019 concluded that Earth faced losing 40% of its insects over the next few decades – it estimated that in 50 years there would only be half the number of insects and in 100 years – possibly none.

Earlier this month, a group of 30 scientists highlighted the issue of falling insect numbers. In articles published in the journal Biological Conservation, Dr. Matt Hill a lecturer at the University of Huddersfield, argued that common insects like beetles, dragonflies, mayflies and snails, among others, are in longterm decline even in the UK.

These insects provide food for other animals and their declining numbers impacts the food chain. They also play an important role in freshwater ecosystems and are a critical component in the diversity of life.

Dr. Hill said that these insects also play a hugely important role in pollination meaning crops are essentially depending on insects to survive. This role cannot be replaced by technology. The loss of habitat, pollution and agricultural practices have all contributed to insect population declines and species extinctions.

Bees cannot be replaced as pollinators
Bees cannot be replaced as pollinators

Dr. Hill and the team behind the research, spanning countries like the UK, Germany, Finland, South Africa and Columbia drew up a nine point plan that could be put in place by people across the globe;

  1. Mow the lawn less frequently. This will allow nature to grow and feed the insects.
  2. Plant native plants rather than exotic plants.
  3. Avoid pesticides, go organic.
  4. Leave old trees and stumps alone. Also old leaves – these are a natural home to many insect species.
  5. Build ‘insect hotels’ with small horizontal holes that can become their nests.
  6. Reduce your carbon footprint – good for the environment and insect numbers.
  7. Support and/or volunteer in conservation organisations.
  8. Do not import or release animals into the wild that are not naturally found there.
  9. Look on the small side of life! Be aware of tiny creatures.

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