Insects are of great importance to many ecosystems and to the human food chain. However, for many reasons, many parts of the world can be insect-free, scientists warn.
The PNAS figure is slightly higher than previous research from many universities and institutes of biology. For example, in 2019, the German Center for Integrated Biodiversity Research analyzed more than 1,700 sites on Earth, showing that the number of insects has declined by almost 27% in just 30 years.
In some places the ratio is even more dire. Insects, for example, have fallen 75% in Germany, 98% in Puerto Rico… in just 27 years. In the Midwestern region of the United States, the number of insects is expected to decline by 4% per year.
This is the rate of severe decline as insects are the most diverse and abundant class in the animal kingdom. It is estimated that every year, species such as grasshoppers, ants, butterflies decrease by more than 0.9% and this rate shows signs of increasing over time.
Most insects play an important role in ecosystems and human production. They help plants pollinate, which is a food source for many other animals in the ecosystem, and help recycle many types of natural waste.
According to Science Alert, around 10 million insect species share the same threats of deforestation, loss of farmland, pesticide abuse, climate change and even light pollution.
Dr David Wagner – an entomologist at the University of Connecticut (USA) who participated in the study – said the insects would die from having too many “wounds” at one time.
Dr Matthew Forister – entomologist at the University of Nevada (USA) – said that although the situation is quite complicated, but not too late. The number of insects is expected to improve further if corrective action is taken promptly.
Recently, many countries have started to take strong action: Germany is pledging nearly $ 120 million for insect conservation, monitoring and research; Costa Rica – a country renowned for its biodiversity – has also received $ 100 million from international organizations to inspect and decode genetic fragments of domestic animals, with priority given to insects.
While the above activities are positive, Wagner and Forister believe there is a need for more new policies as well as close cooperation between countries to address issues such as pesticide abuse and pollution.
Research team member Dr Akito Y. Kawahara – University of Florida, USA – said making things as natural as possible would benefit insects. For example, insect habitats in the United States could increase by more than 4 million acres if homes, schools and parks allow 10% of lawns to grow naturally with native plants and limit light pollution.
