Does the sight of a bullfrog make your mouth water? Does the thought of a swamp rat make your stomach growl? The odds are probably low, but you may want to reconsider.
In the U.S., approximately 50,000 non-native species have been introduced to its lands and waters, according to the U.S. Fish and Wildlife Service. Of those, nearly 10 percent are considered invasive — meaning they likely cause harm to the environment, human health or the economy as they spread. These invaders, which often lack natural predators to keep them in check, cause an estimated $120 billion in economic costs each year, and it’s likely to get worse from here. Regions everywhere are becoming warmer and more hospitable to invasive species, and a 2009 study found that the rise in trade and transport that accompanies globalization will only lead to more introductions in the future.
But this daunting eco-challenge has sparked culinary action in some circles: putting non-native plants and animals on our menus. The response could make a dent in invasive populations while inventing some fun, new meals too. Plenty of restaurants and food suppliers have already heeded the call. Here are a few suggestions to get you started.
Kudzu (Pueraria montana) hails from Asia but was introduced to the U.S. at the 1876 Centennial Exposition in Philadelphia. For the better part of the next century, farmers cultivated the leafy vine en masse to feed livestock and reduce soil erosion. In fact, government agencies funded much of the effort and provided over 85 million seedlings. But a secret danger lurked in its aggressive growth.
Kudzu competes with native plant species, even entire trees, by smothering them from sunlight. And it didn’t take long for the killer vine to outgrow the farmland where it was first cultivated. Currently, it’s estimated that kudzu blankets more than 7 million acres throughout the Southeast and grows at a staggering rate of 1 foot per day — rightfully earning the moniker “the vine that ate the South.”
Luckily, so long as it has not come into contact with herbicides, kudzu is edible. Certain regions of Eastern and Southeastern Asia have utilized its roots, which make up 40 percent of the total plant, as a staple food and herbal medicine (called “longevity powder” or “Asian ginseng”) for thousands of years. But nearly all of kudzu, with the exception of its seeds and seed pods, are safe to eat. Toss the leaves into a soup or salad; pickle the grape-scented purple flowers or transform them into jellies and syrups; or use the starchy roots as a gluten-free alternative to wheat flour in your favorite soup.
Lionfish (Pterois volitans and P. miles) are considered the first invasive marine fish in the western Atlantic Ocean. From Brazil to New York, without any natural predators or parasites, they reach numbers approximately five to 15 times greater than in their natural habitats and can obliterate communities of native fish in coral reefs by up to 95 percent, according to a study published in Reviews in Fisheries Science. There are rumors that the invasion began when Hurricane Andrew broke an aquarium tank in 1992, but DNA analyses of the striking fish suggest that they were actually introduced no later than 1985 at a site along Dania Beach, Florida.
In 2010, the Florida Keys National Marine Sanctuary began giving out licenses to kill the invasive species inside their property. The Reef Environmental Education Foundation hosts “Lionfish Derbies,” awarding prizes to those who catch the largest, smallest and greatest number of lionfish while diving and snorkeling. And ever since the Monterey Bay Aquarium rated the fish “Green” in early 2016, grocery stores like Whole Foods have offered tasty lionfish filets to their customers in an effort to make a dent in the population.
Lionfish has a mild, buttery flavor and can be prepared just like any other fish — once a fishmonger has removed its venomous fin spines. (The venom remains active for up to an hour after the fish is killed, so handle with caution!) Grill it, stew it, bake it in breadcrumbs or roll it into a roulade.
3. Wild boar
Wild boars (Sus scrofa) are native to Eurasia but can now be found on every continent except Antarctica. According to the U.S. Department of Agriculture, the boar was introduced to the U.S. in the early 1900s for the purpose of private hunting. Today, feral swine in the states — with numbers estimated at over 6 million and rapidly expanding — are typically hybrids of these Eurasian wild boars and domestic pigs that have escaped captivity.
But keep in mind that wild boars aren’t your typical pig. According to one report, the pernicious porkers are responsible for over $1.5 billion in annual damage to grassland and forest ecosystems and crops, and are the reason for a national program to mitigate this damage. They can also host a huge variety of viruses, bacteria and parasites; wild boars were linked to a 2007 outbreak of E. coli in California spinach that sickened more than 200 people nationwide.
If you aren’t in the mood to go hog hunting yourself, there are plenty of brick-and-mortar and online purveyors of wild boar meat. Said to be more delicious than domestic pork, thanks to its leaner body, try a bite of rustic wild boar ragout or a barbecue wild boar slider.
4. Green iguana
The green iguana (Iguana iguana), is native to Central and South America and parts of the Caribbean. But the pet trade is to blame for their invasion of Florida, Texas, Hawaii, Puerto Rico and the U.S. Virgin Islands toward the turn of the century. Young green iguanas are commonly purchased as pets due to their small size, price tag and low cost of maintenance. But the cute critters don’t stay small forever — they can grow up to 6 feet in length and quickly outgrow the homes that once wanted them.
Running rampant in Florida’s suburbs, the green iguana devours landscaping and digs burrows that undermine the integrity of sidewalks, canals and seawalls. (Not to mention they unload their bowels at any water source, including backyard swimming pools.) Although primarily herbivores, the iguana also threatens endangered species of tree snails and the endangered Miami Blue butterfly. And in Puerto Rico, the uncontrolled population is known to take to sunny airport runways and cause flight delays — or in worse circumstances, aircraft collisions.
Eating iguana is nothing new. In fact, some South and Central American countries have eaten the native “chicken of the trees” for so long, it is now endangered there. If you’re hankering for your own taste, skin the iguana or dip it in hot water to scrape off its scales, then boil in salt water for half an hour before roasting or stewing to your heart’s desire.
5. Garden snail
The brown garden snail (Cornu aspersum) is found natively around the Mediterranean and in Western Europe. Now, however, the mollusk is one of the most widely spread land snails in the world and is considered invasive in parts of the U.S. and Canada. In many cases, the species was deliberately imported from Europe for food and farming purposes (and for the occasional hobbyist’s snail collection), but it was also accidentally introduced through the crop trade. French immigrants, for example, introduced the snail to California during the 1850s for use as food. Escargot, anyone?
Just a half century later, Californians largely considered the brown garden snail a pest in their citrus orchards. In addition to citrus, the snail is a major threat to other sectors of the agricultural industry: vineyards, vegetables, garden flowers and grain. To combat them, farmers turn to pruning, poison and even the predatory decollate snail — although there is always the risk of introducing further harm to an ecosystem.
If you live in the Southeastern U.S. or anywhere along the West or East coasts, you can join the fight by following the lead of the French; grab a cloth bag and take an evening or early morning stroll through your yard. Snails gathered in the fall are thought to be the tastiest, but they’re also abundant in the spring. And the mollusks are considered fish by the Catholic Church, so there’s no need to be wary of chowing down on meatless days during Lent.
6. Prickly pear
The prickly pear (Opuntia ficus-indica) is native to Mexico and considered the most widespread invasive cactus. Nowadays, it's found in more than 22 different countries, including the U.S., Australia, South Africa and China. A large part of its success has to do with its ability to tolerate drought and regenerate from seeds, stems or roots — but humans had a helping hand as well.
The prickly pear has a long history of domestication. The species originally spread through the Aztec Empire as vital for creating cochineal dye, which later became one of Mexico’s most valued exports. After 1492, sailors using the species’ edible pads to prevent scurvy became responsible for introducing it to the rest of the world. And by the 20th century, cattle ranchers in the Southwest U.S. used the prickly pear plants as animal fodder during drought and as natural, impenetrable boundaries.
Despite its many uses, the prickly pear is considered an “ecosystem engineer” because it quickly takes over the habitats of native plants and the animals that depend on them. Do your part to stop it in its tracks by picking up some of its red fruit from the grocery store. They can be eaten raw or cooked, and the seeds can even be ground into flour. Its pads, assuming you desire a little extra protection from scurvy yourself, can also be eaten raw or cooked. Just remember to remove the thorns.
7. Asian shore crab
Asian shore crabs (Hemigrapsus sanguineus) originated in the temperate and subtropical regions of the western Pacific. Along the intertidal coastline of the U.S., from North Carolina to Maine, the species is considered invasive. It was first observed there near Delaware Bay in 1988, but it’s likely that the crab was introduced via the ballast water of a cargo ship years before. Over the next 15 years, the Asian shore crab population exploded until it became the dominant crab in that region’s rocky intertidal habitats.
This species is responsible for displacing a variety of native ones, including mud crabs and the previously invasive green crab. Its success is attributed to its impressive spawning season (it breeds for twice as long as many native crabs) and its ability to outcompete other species for space and food. This is not a picky eater — there isn’t much that the opportunistic glutton won’t consume if it’s physically capable of doing so, including mollusks and other crustaceans.
To curb their population, you may consider taking a page out of their book. The Asian shore crab, less than 2 inches wide, can be found in clusters under rocks and in tide pools at low tide. But if you aren’t in the mood to forage, chef Bun Lai's sushi dishes in New Haven, Conn., have featured the invasive Asian shore crab since 2001.
The nutria, or coypu (Myocastor coypus), is a semi-aquatic rodent native to South America. Smaller than a beaver but larger than a muskrat, the critters (less-than-affectionately nicknamed "swamp rats") were introduced to Europe, Asia, Africa and North America for fur farming during the late 19th and 20th centuries. Their inevitable invasion is largely attributed to releases by fur farmers — one of whom was none other than E. A. McIlhenny, a Tabasco brand pepper sauce tycoon who released all of the nutria on his farm in order to establish a fur industry in Louisiana — as well as escapes during hurricanes and floods.
Due to its negative impact on native diversity and infrastructure, however, nutrias quickly gained a reputation as pests. The herbivorous rodents weaken irrigation structures with their burrowing habits, play host to myriad diseases and, surprisingly, destroy the eggs of some waterbirds by using floating nests as personal resting sites. Unfortunately, by the time the international fur market collapsed in the 1980s, there were tens of millions of nutria in the state of Louisiana alone.
And they likely aren’t going anywhere soon, as warmer and wetter weather brought about by climate change will only allow the growing population to extend further north — so it may be time to pick up a fork.
9. American bullfrog
Did someone say frog legs? The American bullfrog (Lithobates catesbeianus) is found natively in the lakes, ponds and wetlands of eastern North America. Elsewhere in North America, as well as in parts of Central and South America, Western Europe and Asia, the species is considered invasive. There, the bullfrog ambushes and eats anything that will fit in its mouth: insects, crustaceans, fishes, birds, reptiles and even other amphibians.
Frog legs were commonly eaten in Southern China as early as the first century A.D. and even on the other side of the world, the Aztecs partook as well. In Europe, the first mention of the food comes from the Catholic church in 12th-century France, when hungry monks ordered to abstain from meat successfully categorized the amphibian as a fish.
Nowadays, its invasion into more than 50 countries can be attributed to the international frog trade and the practice of frog farming. The American bullfrog was introduced into Uruguay, for example, for farming in 1987. Now, despite most of its farms being shut down, experts warn that the species is becoming invasive. Brazil is one of the leading countries for American bullfrog farming, producing nearly 500 tons annually.
But the frog is also a vector for the chytrid fungus (Batrachochytrium dendrobatidis), implicated in the extinction of nearly 100 frog species. American bullfrogs pick up the disease at frog farms, where they are raised in crowded containers and shared water, and then pass it to native frog species when they are exported live. For that reason, if you’re seeking a leg to nibble on, experts recommend against purchasing farmed or native frog. Instead, head to a stream or swamp where the bullfrog is considered invasive — in the U.S., that’s west of the Rockies.
Step aside, flower crowns. There's a new use for dandelions (Taraxacum officinale), a perennial herb native to Europe and considered aggressively invasive in gardens, lawns and meadows worldwide. In North America, the dandelion was introduced during European settlement — both intentionally and accidentally.
Europeans used the plant to make wine and medications for fever, boils, diarrhea, fluid retention, liver congestion, heartburn and various skin ailments. In China, India and Russia, dandelions were used to treat breast problems, liver diseases, appendicitis and digestive problems. Now, despite its low ecological impact on native ecosystems, it’s considered nothing more than a nuisance. The plant’s seeds are designed to spread up to 100 miles via the wind; and once it has rooted, good luck removing its 10 to 15 feet of roots without spreading more seeds.
The next time a dandelion crops up in your lawn, try transferring it to your kitchen instead. According to the Cleveland Clinic, the herb is packed with vitamins, folate, calcium, potassium and antioxidants. Toss its arugula-like leaves into a salad or boil and sauté them. Use its bright yellow blossoms to make a dandelion tea or wine, or try infusing them in oil. Even the roots are edible and can be transformed into a tasty drink similar to coffee.
Honorable mention: Asian giant hornet
The Asian giant hornet (Vespa mandarinia), also known as the “murder hornet,” is the world’s largest hornet. It originates from Asia and parts of the Russian Far East but has just been detected in North America for the first time; the first sighting occurred in Washington state in 2019, followed by additional sightings in western British Columbia in 2020 and most recently again in Washington.
No one knows how they were introduced, but it’s all hands on decks to prevent the insects from spreading further. The U.S. Department of Agriculture alone has allocated more than $944,000 toward Asian giant hornet research and eradication efforts for fiscal year 2021. And for good reason. A group of 30 Asian giant hornets can eradicate a colony of honey bees 30,000-strong in less than four hours. One study, published in Pest Management Science, predicts that the invasive species could threaten as many as 100,000 honey bee colonies and cost the U.S. an estimated $11.9 million and $101.8 million in hive derived products and bee-pollinated crops production.
But in some regions of Japan, the murder hornet is considered a delicacy. Along with other wasp species, its larvae are often jarred, pan-fried or steamed with rice. The adults, coming in at around 2-inches long, are fried on skewers. But for some real pep in your step, there's a liquor made from Asian giant hornet venom — live hornets release the venom as they are drowned in a distilled drink, called "shochu." Whether Americans will take to dunking the insects in their whiskey remains to be seen.