Brown marmorated stink bugs have started showing up on the outside of my house, right on cue. Around the autumnal equinox every year (Sept. 20 this year), these Asian invaders start looking for places to spend the winter.
Also coinciding with the bugs’ arrival have been interesting, if scary, articles about how global warming affects the impact of insects on crops. A team of researchers at the University of Washington (UW) recently published in Science magazine the results of a model they developed to try to determine this impact. While insects now consume 5 to 20 percent of our crops, the model indicates that, as global warming ramps up, so does the metabolism and reproduction of some important insect populations, and their consumption of the world’s crops.
Not all insects are likely to benefit from global warming. Unless they can disperse, some species in the tropics that are already working at the limit of their heat tolerance may start disappearing. Meanwhile, the metabolism and reproduction of insects at higher latitudes, which have been working at the edge of their cold tolerance, may rev up.
It is in those cooler latitudes that some of the crops we humans depend on the most are grown. Wheat, rice and corn, for example, may be especially hard hit, with losses increasing by 10 to 25 percent for each degree Celsius (1.8 degrees Fahrenheit) of temperature rise. At the current rate, the average global temperature is expected to rise 2 C by the end of the century. While consumption of some crops is expected to level off, the hit to other crops will likely continue going up in tandem with temperature rises.
According to other articles in Science about the UW study, the researchers acknowledge that many factors that could ameliorate the situation were not considered in their model. These include the response by natural predators of insects to warming, the possibility of insects changing their diets as temperatures rise, and changes in farming that develop to meet the challenge. But if the model does hold true, we won’t be able to poison our way out of the situation predicted without endangering ourselves and other species on the planet.
There is one way to beat the crop-consuming bugs: eat them. Most are excellent sources of protein and other nutrients. Humans in 113 countries traditionally insects, according to Wageningen University & Research, a Dutch organization that collects data on edible insects (and spiders). It lists 2,111 species around the world that are known to be edible. Considering how little we know about insects, the number could be higher. According to a Smithsonian article, an estimated 10 quintillion (10,000,000,000,000,000,000) individual insects, organized into 900,000 species, are known to inhabit our planet. They represent “approximately 80 percent” of the world’s animal species and the largest biomass among terrestrial animals.
Globally, according to WUR, the most frequently consumed insect species are beetles, caterpillars, bees, wasps and ants, followed by grasshoppers, locusts and crickets, cicadas, leafhoppers and bugs, termites, dragonflies, flies and other species. (For the list of countries and species, visit their website.)
I already have a recipe for cicadas I received from a local entomologist, which he sent to me in conjunction with my writing about the emergence of Brood II of our 17-year periodical cicadas in 2013. I’m sure it can be applied to our annual cicadas as well. The Smithsonian Channel series “Bug Bites” offers more suggestions, as does author David George Gordon in “The Eat-a-Bug Cookbook.” The Atlantic magazine podcast “Crazy/Genius” also has an episode coming up on “Meatless Meat,” in which Mark Post, inventor of the first lab-grown burger, and Andrew Brentano, of the cricket-harvesting start-up Tiny Farms, discuss how embryonic meat and insect-based foods could save billions of other animals.
I recently found a beautiful pair of camel crickets in my dog’s dish when I left it outside overnight. Looking at their zaftig physiques, I thought they’d make some predator a lovely meal rich in fat and protein. Like many orthopterans, they’re known for their ferocious and diverse appetites, pretty much eating anything organic but are otherwise harmless to humans. Camel crickets (in the insect family Rhaphidophoridae) are named for their dromedary-like shape but are also known as cave crickets because they prefer cave-like conditions: cool and damp. Rather than singing, these crickets find mates by accidentally bumping into them during their daily roaming.
So, in the future, will the old saw “eat an apple a day” be replaced by “eat a cricket a day” as the planet continues to heat up? Only time and rising temperatures will tell.
© 2018 Pam Owen
Fall nature events
National Public Lands Day (Saturday, Sept. 22-29): Celebrate the 25th annual National Public Lands Day (this year on Sept. 22) with free parking, special programs and volunteer events all week at all 37 Virginia state parks. The national theme for this year is “resilience and restoration, and many state park projects involve invasive species removal, trash pickup, river and shoreline cleanup, trail maintenance, habitat restoration, and environmental education programs and activities.” Nearby Sky Meadows, in Delaplane, invites volunteers to visit and help refresh nests in bluebird boxes. For more information about the events, go to vasp.fun/NPLD25years. On Sept. 29, Virginia state parks also celebrate Bike Your Park Day by inviting cyclists to “bring your bike and enjoy your parks.”
Saturday Bird Walk (Saturday, Sept. 22, 7-10 a.m.): Novice and experienced birders are invited to this free, guided 1- to 2-mile hike to look for the many species of birds at The Clifton Institute. Led by local birder David Larsen, explore successional fields, meadows, lake edges and forest during the fall bird migration. Binoculars and cameras are recommended; outdoor clothing, including waterproof footwear and hats are suggested. At 6712 Blantyre Road, Warrenton. Register on the institute’s website; contact director Bert Harris (email@example.com) for more information.
VNPS Fall Plant Walk (Sunday, Sept. 23): Take an easy walk through autumn fields at Clifton Institute. Join Jocelyn Sladen, a director at The Clifton Institute, and Sally Anderson, former president of the Virginia Native Plant Society, to learn to identify grasses, native trees and shrubs, and late wildflowers. Dress for the weather, wear sturdy shoes and a hat, and bring sunscreen, insect repellent and drinking water. At 6712 Blantyre Road, Warrenton. For more information for this free event, email firstname.lastname@example.org.
Community Clean Water Workshop (Wednesday, Sept. 26, 6:00-8:00 p.m.): Attend this information session hosted by PEC and the Virginia Conservation Network to learn how to protect the water in your backyard and advocate for clean water at the state and federal level. Issues addressed are best management practices, citizen water quality monitoring and other ways to get engaged in local water issues. Free and open to the public, but preregistration is required due to limited space and to provide refreshments. Contact Claire Catlett at email@example.com with any questions. At the PEC Warrenton office, 45 Horner St.
Conservation Discovery Day (Oct. 6, 9 a.m.-4 p.m.): What used to be the Smithsonian’s Conservation Biology Institute’s Fall Festival has morphed into Conservation Discovery Day is designed for high school and undergraduate students interested in the conservation field. The day will include hands-on activities, research demonstrations, and career panel discussions with conservation biologists, field ecologists, research scientists, veterinarians and animal keepers. According to a spokesperson, “It’s the one day of the year this facility is open to the public, so don’t miss your chance to learn how you can join the conservation ranks and make a difference for wildlife and habitats worldwide!” At SCBI, Front Royal; to learn more about the event and to purchase tickets, go to SCBI’s website.