In the summer of 1875, it took a swarm of about 10 billion locusts close to a week to pass through Plattsmouth, Nebraska. Some 30 years later, the species went extinct, leaving the ecosystem damaged, since they provided food for a significant number of insectivores.
Some more recent insect population statistics are even scarier. Namely, 40% of all insect species are in decline or on the verge of extinction.
Everyone knows that bees are dying in high numbers and that we’d be left with minimal food sources if they disappeared completely. But should we worry about the ladybugs and butterflies in the same way we worry about bees?
Keep reading if you want to find out why insects are important and how their disappearance would affect the world.
The Top 10 Statistics on the Decline in Insect Populations
- There are several million species of insects in the world.
- One-third of all insect species are endangered.
- Only 84 species of insects in the US are listed as endangered or threatened.
- America’s soil is 48 times more toxic to insects than 25 years ago.
- Global warming has killed 98% of insects in Puerto Rico’s Luquillo rainforest.
- The use of herbicide is the second-greatest cause for the decline in insect populations, according to insect population statistics.
- In 2018, less than 200,000 monarch butterflies were overwintering on the coast of California.
- More than 20 butterfly and moth species in the US are listed as endangered.
- 36% of the 39 dragonfly species are in decline.
- Asian hornets are spreading at the pace of 62 miles a year.
Keep reading to discover more about why insect populations are declining.
How Many Species of Insects Are There in the World?
Insects are the most diverse group of animals, with the highest number of species. But how many of them are there?
1. There are several million species of insects.
Contrary to popular belief, insects are the dominant form of animal life on Earth.
Compared to 5,416 species of mammals, almost a million insect species have been described so far. And according to the insect population data, there could be up to 30 million species of insects.
2. A third of all insect species are endangered.
The world’s insect species are moving towards extinction at worrying rates.
According to the research, the rate of their extinction is eight times faster than those of mammals, reptiles, and birds. At this rate, insects could disappear within 100 years.
3. A study from 2017 shows that 76% of flying insects in Germany had disappeared.
Following several high-profile papers on this topic, a group of European researchers discovered that this staggering decline happened over just 27 years within 63 protected areas of Germany.
4. Arthropod biomass in the Luquillo rainforest in Puerto Rico has declined between 10 and 60 times.
Rainforests are known for being the most biologically diverse regions in the world, and insect biomass has always been one of the most significant parts of that diversity.
The temperature of the rainforest has been rising since the 1970s, causing its food chain to collapse. From this, it’s clear that global warming affects all species on the planet.
5. Only 84 species of insects in the US are listed as endangered or threatened.
(ENTSOC, Scientific American)
However, scientists believe that the number is higher.
There are several reasons behind this underrepresentation, like habitat specificity or dependence on a host plant or animal that is itself rare.
But is the insect apocalypse debunked with the data? The answer is complicated.
The data clearly shows that some insect species are declining dramatically, but these statistics might be location-specific and not a global trend. In some cases, they don’t even indicate a local problem.
Even though we might not see an insect apocalypse, many insect species are still dying out at alarming rates, and there are numerous reasons behind this trend.
Why Are Insects Dying?
One of the most apparent reasons for the decline in insect population is the use of pesticides.
The loss of habitat can also endanger the existence of a species. Furthermore, habitat degradation and the decline and disappearance of plants and animals that insects depend on for food and shelter.
Moreover, water pollution also has devastating effects on the environment and contributes to the problem of insect extinction.
6. America’s agriculture is 48 times more toxic to insects than 25 years ago.
(PLOS One, National Geographic)
The agricultural landscape is toxic because of the widespread use of neonicotinoid pesticides, which can remain toxic in the environment for up to 1,000 days.
The pesticides are responsible for 92% of increased toxicity. This is because plants absorb these chemicals into all of their tissues — stems, leaves, pollen, nectar, and sap.
According to the study on insect population decline that was conducted in 2019, these chemicals are incredibly toxic to pollinators like bees and butterflies, while birds aren’t spared either.
7. A study conducted in Sweden in 2018 revealed that, at the time of the study, there were 62% less nocturnal pollutions due to light pollution.
The study showed that artificial lights disturb nocturnal pollinators, which leads to a severe decline of seed sets.
Artificial lights also impair the effectiveness of illumination methods that some flowers use to attract pollinators, as the study on insect population decline from 2018 found.
8. Global warming has killed 98% of insects in Puerto Rico’s Luquillo rainforest.
Climate change is significantly affecting all living beings on the planet, but the Luquillo rainforest is suffering the most.
Over the last 30 years, the temperature in this rainforest has increased by two degrees Celsius (35.6°F), which eradicated almost the entirety of the rainforest’s insect population.
9. The use of herbicides is the second-greatest cause for the decline in the insect population, as insect population statistics show.
In the 1980s, insects occurred at a rate of 100 kilograms per hectare in North America alone. This makes their biomass 15 times greater than that of all people, birds, and non-human mammals from the same area combined.
Fields were filled with a diversity of wild plants — the main food for insects.
In the UK, the use of herbicides has increased so much that there’s only sandy soil and crop left, leaving insects without their main food source.
Insect Population Decline
This rapid decline in the population of insects is a sign that the sixth mass extinction of insects has already begun.
Globally, the most affected species are bees, butterflies, moths, dragonflies, and damselflies, but other species are in great danger, too.
10. In 2018, less than 200,000 monarch butterflies were overwintering on the California coast.
Around twenty years ago, more than 1.2 million monarch butterflies were recorded on a smaller number of coastal sites in California, as the insect population statistics show.
However, there were approximately 300,000 monarchs in 2017, and the number dropped even more in 2018.
Furthermore, the population estimates at individual sites also suggest that the western monarch population is declining.
11. The population of ladybugs in the US and Canada has declined 14% from 1987 to 2006.
Flying insects are almost a thing of the past, and ladybugs are no exception.
Scientists agree that the probable causes for this phenomenon are the widespread use of insecticides and pesticides, light pollution, and climate change.
People have also been encouraged to conduct the un-scientific “windshield test” (the number of insects squashed on car windshields).
The test could reveal that the ladybug population is decreasing, but the test itself is not quite reliable because it doesn’t include a control group.
Furthermore, modern cars are more aerodynamic, allowing insects to avoid an impact.
12. More than 20 butterfly and moth species in the US are listed as endangered.
(Save Our Monarchs)
The loss of habitat is the main reason these species are endangered.
Additionally, pesticides, herbicides, and poor land management practices also led to the loss of the butterfly’s host plant, which is their primary source of food.
13. The overall number of moths in the UK has declined by 28% since 1968.
Insect decline is the most severe in southern Britain, where the moth population has declined by 40%, and some moth species that were previously common have now become rare.
Furthermore, more than 60 moth species had disappeared entirely over the course of the 20th century.
14. 36% of the 39 dragonfly species are in decline.
Scientists in the UK have collected data that shows that habitat destruction (fewer ponds where dragonflies spend 95% of their lives) and global warming are endangering the survival of one-third of the dragonfly species in Britain.
Insect Population Growth
With humanity’s growing ecological footprint, there has been a rise in the numbers of some insect species.
Unfortunately, the change in the environmental conditions has led to the population growth of insects that are harmful to trees, crops, people, etc.
15. There are more than 110 trillion mosquitoes in the world.
Mosquitoes are notorious for the spreading of numerous diseases, such as the Zika virus, West Nile virus, malaria, and dengue. And their number is increasing due to climate change.
Traditionally, mosquitoes follow people wherever they go. So with the rise in the global temperature, people are moving further north, which in turn increases the bug population.
16. Asian hornets are spreading at the pace of 62 miles a year.
Warmer weather has enabled these killer wasps to travel away from China and “invade” Europe and the US.
Besides being dangerous to people, they’re also deadly to honeybees. Less than 30 hornets can wipe out a 30,000-honeybee colony in hours.
17. Are insect populations declining?
Not all insect populations are declining.
Unfortunately, pollinators like butterflies and bees are currently dying out, while the insect species that are considered pests — like beetles and stink bugs — are increasing in numbers.
18. Are the insects dying?
Sadly, yes. And at this rate, they could all disappear in just one century.
19. How many insects are dying?
So far, 40% of the overall insect species have seen a decline in numbers. Moreover, It’s estimated that 40% of the 30 million insect species on Earth are in danger of becoming extinct.
20. What happened to all the insects?
Climate change is responsible for the majority of insect species dying out or being on the verge of extinction.
21. Why are bugs dying?
Bugs have been disappearing due to intensive agriculture, the widespread use of dangerous chemicals, and loss of habitat.
22. How fast are insects dying?
Insects are dying eight times faster than mammals, reptiles, and birds.
23. What happens if all the insects died?
Without insects, the world would collapse due to starvation. Even though they seem as annoying little creatures, 80% of them provide the world with food.
24. What would happen if the population of insects decreased?
The population of insects has already reduced, which has caused a significant decline in other species, as well, since many animals feed on insects.
25. Is the world population declining?
The global population of insects is declining, making a third of them endangered.
26. Why are pollinators dying?
Pollinators are dying out mainly due to the pesticides and insecticides that plants absorb. They feed on the toxic plants, which causes them to die.
Other reasons include air and water pollution, as well as climate change, habitat destruction, and competition between native and invasive or introduced insect species.
27. What is the current human-to-bug ratio?
It’s estimated that there are 200 million insects for every human on the planet. This also means that there are approximately 300 pounds of insects for every pound of humans.
The Bottom Line
The proof is in the insect population statistics — these little creatures keep the world turning. From providing food to being food, they’re one of the main parts of the global ecosystem.
This list of statistics shows just how essential insects are and how people are destroying the world with deforestation, pollution, invasive agriculture, and other harmful activities.
By saving insects, we’re saving other living beings, too, including ourselves.