And when conditions become uncomfortable, they're experts at 'getting the heck out of Dodge'.
However, current rapidly changing temperature and precipitation patterns present serious new challenges for insects. These changes, accompanied by decades of climate stressors such as diminished and degraded landmass, are proving to be even more critical threats for insects.
Altering gene flow
If the phrase sounds ominous, that's because it is. Current climate changes are altering ecosystems at unprecedented speeds and on a much greater scale than ever before. This is a crucial time; however, the results of global environmental changes also offer new opportunities to study species' limitations.
The insect family tree represents almost half the animal species on the planet. It has recently been revised after genetic analysis revealed new relationships between four major groups of insects.1
Contrary to previous assumptions, scientists have found that flies and moths are most closely related to beetles and more distantly related to bees and wasps. About half of all animal species belong to just four groups of insects.
These insects represent the four major orders of holometabolous insects: beetles (Coleoptera), moths/butterflies (Lepidoptera), flies (Diptera), and wasps/bees (Hymenoptera). These four orders account for 45% of all animal species on the planet. Also included are one grasshopper (Locusta migratoria) and one pea aphid (Acyrthosiphon pisum).
Increases and fluctuations in temperature have the potential to alter gene flow between species by forcing them to behave in certain ways, interact differently, or move to new locations.
This is particularly true for insects. Their geographic ranges, behaviors, and traits are always dependent on climate, especially temperature. Climate change has the potential to influence gene flow and species boundaries between closely related insect species.
How temperature affects insects
Insects are cold-blooded creatures that can’t produce their own body heat. The temperature of their surroundings plays a primary role in their development and behavior.
Insects adapt to cooler temperatures by migrating to warmer locations, hibernating, or seeking shelter almost anywhere, from underground to inside homes.
During cool weather, many insects become sluggish. Following a cold night, grasshoppers are frequently too stiff to move until warmed by the sun. And some flying insects are unable to move their wings fast enough to fly once the temperature drops.
With the exception of tropical zones, insect reproduction usually increases during warm months. That's why you notice an increase of bugs as the temperature begins to rise.
When temperatures rise, so does the speed of insect metabolism. This means they need more food to survive. You may notice increased insect damage in your garden or more bugs invading your home.
Click this link to find your state insect: https://en.wikipedia.org/wiki/List_of_U.S._state_insects.
Threat to the food supply
For decades, scientists have been warning that climate change will impact the food we grow. From rising global temperatures to more frequent extreme weather, such as droughts and floods, climate change is expected to negatively affect our ability to produce enough food for the growing human population.
New research shows that climate change is expected to accelerate rates of crop loss due to the activity of hungry insects. Temperatures in crop-growing regions will rise. Researchers project this will boost worldwide losses of rice, corn, and wheat by 10-25% for each degree Celsius the surface temperature rises. Just a 2° rise in surface temperatures will push the total losses of these three crops alone to approximately 213 million tons each year.2
Food insecurity increasing
The United Nations has estimated that at least 815 million people worldwide currently lack enough food. Global warming impacts on pest infestations are aggravating this problem. Increasing environmental damage as a result of greater pesticide use and GMOs is skyrocketing.
Some positive news: agronomic practices such as crop rotation have been proven to help control losses from insects.
Too little too late?
Unfortunately, all of the current climate change scenarios show pest populations are winning, particularly in highly productive temperate regions. This will cause a rise in food prices and food-insecure populations will suffer.
In addition, hotter weather boosts insect reproduction. Temperate regions are currently cooler than most insects prefer. If temperatures rise there, insect populations will increase more quickly and require more to eat, resulting in increased crop damage and less food.
Even a small change has a huge impact
A 2° rise in global surface temperatures means that median losses in yield due to insect activity would be 31% for corn, 19% for rice, and 46% for wheat. Under those conditions, total annual crop losses would reach 62, 92, and 59 million tons, respectively.3
Much of the world’s rice crop is grown in the tropics. Temperatures there are currently at optimal conditions to maximize insect reproductive rates. Additional increases in temperature in the tropics would not boost insect activity to the same extent as in temperate regions such as the U.S. corn belt.
Farmers and governments sometimes attempt to lessen insect impacts by utilizing crop rotation or by attempting to engineer insect-resistant crops. However, the latter takes time and a significant amount of money. In addition, the highly-debated practice of genetic engineering opens yet another can of worms.
What can we do?
There is no easy answer or quick fix. The ongoing climate crisis has become an emergency that is currently being seen and felt via record-breaking heatwaves and relentless drought.
The real question is what it will take in order to speed up the depletion of heat-trapping gases that currently over-saturate our atmosphere. The answer is fourfold: awareness/demand by consumers, innovations by farmers, public policy changes, and public/private investment. Organizations such as The Rainforest Alliance now sell numerous local products like coffee online.
In order to provide sufficient funds to enough farmers and ranchers around the world to allow them to adopt regenerative practices, we must move beyond the false concept of carbon credits and instead adopt the use of true regenerative carbon offsets. Also necessary are substantial direct payments to farmers and ranchers for scientifically verifiable, sustainable, ongoing, and transparent Co2 sequestration practices.
There is hope, but time to act is running out.