They’re one of earth’s smallest species, but they’re at the center of one of this century’s biggest environmental crises: insects. These little creepy-crawlies are dying out rapidly. Even more concerning? Not many people care. Recently, people have started thinking about the bees and what their disappearance means for our agricultural systems, but what about other bugs?
I’ve endured my fair share of itchy bites and can safely say that I don’t like insects at all — but after reading up on the scale and environmental impact of declining insect populations, I now know that we need to save the bugs. All of them.
How big is this decline?
In 2017, a European study of 63 protected reserves in Germany found that flying insect biomass had decreased by more than 75% over 27 years (1989–2016). Scientists were alarmed. Not only did this quiet vanishing act take place on a massive scale, the decline had occurred within nature reserves — where wildlife species are meant to thrive. A study published the following year found that such decline was, of course, not limited to Germany: The pristine El Yunque Rainforest in Puerto Rico saw its insect populations fall 10 to 60 times between 1976 and 2012.
Insects vastly outnumber humans. Won’t they just bounce back?
Yes, the biomass of insects is about 17 times greater than the biomass of humans, and bugs are incredibly resilient creatures. But “bouncing back” isn’t such a simple endeavor. Insects do not exist in a vacuum, and humans can be quite deadly when it comes to supporting our rapidly-expanding population. A study in a 2019 volume of Biological Conservation identified four primary causes of the insect decline, all having to do in some part with humans:
- Habitat loss due mostly to agriculture and urbanization
- Pollution by fertilizers and pesticides
- Introduction of invasive species
- Climate change
The absence of insects is affecting animals around the world. Because they comprise the base of the food chain (just above vegetation), insects decide the fate of the creatures that rely on them as a source of food, and the creatures that eat those creatures, and so on. For example, some species of anole lizards, which are insectivores, vanished from El Yunque Rainforest entirely, and anoles’ total biomass declined by more than 30%. Insect-eating birds showed about a 50% decrease in population, while birds that ate fruits and seeds demonstrated no change in population.
Furthermore, insects do much more than serve as food — they are earth’s silent workers. From crop pollination to waste and nutrient recycling to keeping pests in check (e.g. spiders that eat flies), insects are responsible for saving us billions of dollars.
What can we do to save the insects?
If we look back at the four major causes of insect declines, we can chart a course correction:
- Prevent habitat loss by slowing the conversion of land to human uses
- Eliminate pesticide use to reduce the intentional killing of insects
- Refrain from introducing invasive species
- Reduce greenhouse gas emissions to slow climate change
Numbers 1, 2, and 4 would be much easier to tackle with a human population that is no longer growing. Let’s see if we can get the biomass of insects to be even more than 17x the biomass of humans—the more the merrier, as long as they’re not biting me!