What Is Bugging the Planet?
By Andrew Mentock
American biologist E. O. Wilson once said: “If all mankind were to disappear, the world would regenerate back to the rich state of equilibrium that existed 10,000 years ago. If insects were to vanish, the environment would collapse into chaos.”
As the global climate continues to warm due to human actions, Wilson’s words are proving prescient. But the impact of climate change on insects is wide-ranging. In some instances, warmer temperatures have decimated populations of creepy-crawlies. But that’s not the whole story. For weeks, authorities in New England, Pennsylvania and the Upper Midwest have been warning about invasions of lanternflies and tree-killing insects. Today’s Daily Dose shows you how, when it comes to insects and the warming of the planet, there will be both winners and losers — only, the victors often appear to be the bugs we’d rather eliminate.
PLANT DEATH BY PEST
The Migration of Tree-Killing Bugs
They’ve moved north. Tree-killing insects such as the emerald ash borer, the goldspotted oak borer and the mountain pine beetle are migrating to previously unscathed parts of North America. Why? Experts point to a longer life cycle resulting from earlier springs and warmer winters. At minus 20 degrees Fahrenheit, a temperature often seen in the Midwest, “you can expect about 50% of the emerald ash borer to die in the winter,” Rob Venette, a research biologist with the U.S. Forest Service and director of the Minnesota Invasive Terrestrial Plants and Pests Center, tells OZY. “But if it gets down to minus 30, and minus 30 used to be very common in the northern part of the state, you’d expect about 90% of emerald ash borers to die.” Venette fears warmer winters will push this northern invasion further.
Accelerating Climate Change Effects
Healthy trees are carbon dioxide-soaking life forces. But with beetles killing off millions each year, the dead trees pose a climate threat. Research suggests that rotting trees contribute to the devastating effects of climate change. “What happens when trees die is they decompose, and a large fraction of that dead carbon will ultimately be released into the atmosphere,” Andrew Liebhold of the U.S. Forest Service tells OZY. “These insects and disease invasions appear to be aggravating the atmospheric carbon dioxide problem because they’re accelerating rates of tree mortality.”
Rice, corn and wheat are the three most consumed crops. As temperatures rise, research suggests the earth will experience a devastating loss of all three to insects, which already eat a significant portion of each crop. With each degree Celsius rise, expect pesky insects to gobble up an additional 10% to 25% of these staple crops, exacerbating global food insecurity. “We expect to see increasing crop losses due to insect activity for two basic reasons,” says Curtis Deutsch, a University of Washington associate professor of oceanography. “First, warmer temperatures increase insect metabolic rates exponentially. Second, with the exception of the tropics, warmer temperatures will increase the reproductive rates of insects. You have more insects, and they’re eating more.”
HEIGHTENED THREATS TO HUMAN HEALTH
Future Zika Outbreaks
Five years ago, Zika was considered a global health emergency. Its symptoms were usually mild, but some who caught the virus suffered paralysis. What’s more, it was found to cause serious birth defects for 1 out of 10 pregnant, infected U.S. women. The virus has primarily been found in Aedes species mosquitoes prevalent in the climates of tropical Africa, Southeast Asia and the Pacific Islands. “In cooler temperatures, the virus may take too long to replicate, with the mosquito dying before it becomes infectious,” says Dr. Marcus Blagrove, a virologist at the University of Liverpool. But in 2020, Blagrove and his colleagues mapped the future risk of Zika. If temperatures continue to rise quickly, mosquitoes carrying the Zika virus could migrate to the northern U.S., China, Eastern Europe and Japan by 2080.
Deadly Last Kiss
The kissing bug, a six-legged insect with two sets of wings and an exoskeleton slightly larger than a penny, has a disgusting way of making you sick. Like mosquitoes, they survive on animal blood, and their flirty name comes from their propensity for landing on your face while you sleep. In exchange for blood, it leaves behind the parasite T. cruzi, which can lead to infections of the potentially fatal Chagas disease. The bug’s bite alone can cause anaphylactic shock. Traditionally, kissing bugs were found in Latin America and the southern United States, but researchers have long predicted they would travel north with rising temperatures. Recently, a kissing bug bite was discovered in Delaware. Luckily, well-built U.S. homes typically do a good job of keeping the pests out.
Lyme Disease on the Rise
In 28 years, the incidence of Lyme disease cases per 100,000 Americans almost doubled, according to the Environmental Protection Agency. The vector-borne disease, commonly associated with the tick, leads to fever, skin rash, flu-like symptoms and weakness. The EPA reports that the most significant Lyme disease increases have occurred in northeastern states such as Maine, Vermont and New Hampshire. Ticks are historically found in that part of New England, and their lifespan is growing as we see longer periods where the ground temperature stays above 45 degrees.
The populations of a significant portion of the earth’s pollinators are declining, with climate change a key contributor. Depending upon the climate, the percentage of flowering plants that count on pollinators to assist in the fertilization process is anywhere between 78% and 94%, with plants in tropical areas needing them most. There is a wide range of creatures that are pollinators, from hummingbirds to bats to thousands of insect species. If they can’t do their job to aid the plant’s growing process, foods we know and love — chocolate, coffee beans, apples and zucchini, to name a few — could dwindle.
Beauty Faces Extinction
Considered one of the most beautiful and majestic of insects, the butterfly is also an accomplished pollinator. Unfortunately, a recent study looking at more than 450 butterfly species saw a steep decline, especially in the case of the western monarch, commonly found on the Pacific coasts of California and Mexico, whose numbers have waned by 99.9% over the last 40 years. Because the declines have occurred in areas underdeveloped by humans, a recent study deduced that climate change may be the most prevalent cause. “Our impacts of carbon usage have now changed the environment so much that those areas are now drier and hotter into the fall,” Kathleen Prudic, a co-author of the study and an assistant professor at the University of Arizona, tells OZY. She explains that it’s becoming less hospitable for most living organisms, especially insects. In addition to their roles as pollinators, butterflies, as well as caterpillars, are a major source of food for a variety of animals, including dwindling bird populations.
What About the Bees?
The honeybee is not at risk of extinction. On the contrary, managed honeybee colonies are on the rise. But there are actually more than 20,000 known bee species, and many are in decline for a variety of reasons, from loss of habitat to new parasites and diseases spread by globalization. To a lesser degree, erratic weather brought on by climate change is also problematic. “That makes it very, very difficult for insects that are dependent on floral sources for their nutrition to be in sync with the plants,” Kirsten Traynor, the director of the Institute of Bee Research in Germany, tells OZY. For instance, if the life cycle of a particular plant changes due to warmer temperatures, such as the time of year when it blooms, this can cause some native bees to miss their short pollination window.
Adjusting to the Heat
Some insects are more resilient than others and instead of simply migrating toward cooler temperatures, they’ll actually be able to stand the heat. Researchers have discovered that ants living in microclimates known as “heat islands” that exist in some U.S. cities are doing just as well as their neighbors living in cooler, rural areas nearby. “What we’re finding is the potential for ants — and other animals, perhaps — to evolve in response to anthropogenic [human-caused] climate change,” says Sarah Diamond, the lead researcher of a report titled “Ants, Acorns and Climate Change.” This, however, doesn’t take into account the potentially devastating effect the accelerating loss of certain plant species globally could also have on ants. As for the pesky cockroach, studies have shown it can handle much higher levels of radiation than humans. So it should come as no surprise that this adaptable bug has a better chance of surviving the horrors of climate change than most other insects.
Want to Get Involved?
You can do your part. Scientists rely on everyday citizens to help count insect populations, either by watching for native species or by alerting the scientific community to invasive pests. This allows scientists to use the “manpower of citizens on the ground to try and survey widely to see what is still being found,” Traynor says. “With very little knowledge, you can really contribute to science.” The research can assist policymakers in making more informed decisions when it comes to the conversation now and for the next 100 years.
There’s an App for That
One popular tool used by citizen scientists around the globe is iNaturalist, an online social network for sharing biodiversity information, including information on insects. The data collected from hobbyists is then shared with the Global Biodiversity Information Facility in Denmark, a “warehouse” that scientists rely on for biodiversity research. Another digital tool for aspiring and experienced citizen scientists is the website eButterfly, which compiles information on — you guessed it — butterflies. A handful of U.S. states, such as Georgia, also track insects, which runs a pollinator census. Similarly, the New York State Department of Environmental Conservation recently asked residents to photograph and report sightings of the invasive lanternfly, which is deadly to many North American plants.
- Andrew Mentock, OZY Author Contact Andrew Mentock