Global Decline of Insects

A recent analysis of 74 reports from around the globe shows that the biodiversity of insects is being seriously threatened. The studies come from multiple countries with the majority being in Western Europe and the United States. China, Australia, Brazil, and South Africa also contributed.

The report indicates that 40% of the insect population is currently declining with 1/3 of the population already endangered. This could lead to the extinction of 40% of the insect population in a few decades. At this rate, insects are declining 8 times faster than mammals, birds, and reptiles. While insects may not seem like a major cause of concern, they are in fact, essential for all ecosystems to function correctly. Insects are at the center of food webs, pollinate countless plants, keep soil healthy, in addition to controlling other pests.

Declining bug populations isn’t limited to insects that are specialized to a region, but in fact affects common insects, as well. For instance, one species of bugs currently in decline is beetles. There are over 350,000 species of beetles with many of them shrinking in population, particularly the dung beetle. Another example would be the honey bee. There were 6 million honey bee colonies in 1947, however, 3.5 million have been lost since then. Furthermore, a study in 2013 showed that the honey bee population in Oklahoma declined 50% compared to 1949.

Interestingly, it was discovered that a small number of insect species are actually increasing. These insects were determined to be adaptable species, who are simply taking the place of the dwindling species. Unfortunately, this increase is not enough to make up for the decline.

The rapid loss of insects can be linked to four major factors. One factor is pollution from chemicals, such as pesticides and fertilizers. Another factor is biological influences such as pathogens or introduced species. Finally, there is habitat loss due to urbanization and agriculture. This is, in fact, the main cause of insect decline. It’s necessary to remove tree and shrubs for both farming and construction, but both result in fewer habitats for pests. In the case of agriculture, it often leaves behind bare fields with sterilized soil.

Given these factors, researchers do outline ways for us to allow declining populations to recover. For instance, since agricultural methods are thought to be the major factor, it is suggested that we alter these practices. One way to do this would be to increase the amount of organic farming versus conventional farming. A larger amount of organic farming would reduce the number of chemicals and presumably allow more bugs to survive.

Another option to mitigate insect decline is to reduce the effects of climate change. The effect of climate change on pests is particularly evident in the tropics. In these areas, where there isn’t a large presence of industrial agriculture, the decline is contributed to rising temperatures. The pest species are adapted to the current temperatures and do not have the ability to adapt to hotter conditions.

Unfortunately, there isn’t one simple solution to reverse the decline of insects. However, now that we are aware of the issue, there are factors to consider changing relating to climate change and agricultural practices. If no changes are made, the insect population appears to be at great risk.

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Carrington, Damian. “Plummeting Insect Numbers 'Threaten Collapse of Nature'.” The Guardian, Guardian News and Media, 10 Feb. 2019,
Sanchez-Bayo, Francisco, and Kris A.G. Wyckhuys. “Worldwide Decline of the Entomofauna: A Review of Its Drivers.” Biological Conservation, Elsevier, 31 Jan. 2019,