Aphrodisiac larvae in Mexican mezcal all come from the same species of moth

GAINESVILLE, Fla. — Aphrodisiac larvae added to bottles of Mexican mezcal for flavor all come from the same species of moth, a new study suggests. Researchers seeking to discover which species of worm-looking larvae are the most common in bottles of mezcal — an alcoholic drink similar to tequila made from agave plants — are revealing some surprising findings about the DNA of 18 larvae floating in these bottles.

The scientists unexpectedly found that all the larvae hailed from the same species of moth which feeds on agave plants — Comadia redtenbacheri.

Their presence as the official worm of mezcal cements the insects’ status as an essential part of the mezcal industry, which is worth an estimated $386.4 million and is predicted to more than triple in size in the next 10 years.

mezcal agave plant
Mezcal is made from the boiled and distilled sap of various agave species. CREDIT: Charles Lemaire

Why is mezcal different from tequila?

Mezcal describes any kind of distilled alcoholic beverage coming from any type of agave plant. Meanwhile, tequila comes from one specific type of agave plant. Typical mezcal drinks range in strength from 40 percent abv (alcohol by volume) to a lethal 55 percent. Its name comes from the ancient Aztec language Nahuatl, meaning “oven-cooked agave.”

One of the most globally famous mezcal drinks is tequila, made from the blue agave plant, with many people typically drinking it with salt and lime or as part of a margarita cocktail. More than 70 percent of the mezcal in the world is made in the southern Mexican state of Oaxaca, and many bottles contain insect larvae which flavors the drink.

The same worms are also an ingredient in some Mexican foods. Some believe they have health benefits and aphrodisiac properties. It is tradition, for example, for the maid of honor at a Mexican bachelorette party to eat the worm in a symbolic gesture of the bride passing the torch to her closest loved one, much like throwing the bouquet at a British or American wedding.

However, a group of scientists recently wondered what different species the larvae found in different bottles of mezcal belonged to. So, in a study published in the journal PeerJ Life & Environment, they set out to identify the differing species of larvae.

bottles of mezcal alcohol
Different kinds of mezcals tested for the identity of “mezcal worms.”.
Worms have been removed from bottles in the image. Photo by Akito Y. Kawahara.

Could these worms actually go extinct?

The researchers ran DNA tests on larvae in 21 different, commercially-available bottles of mezcal purchased between 2018 and 2022, in order to determine their identity. The study team found that all the larvae appeared superficially similar, though some were white and others were a pinkish-red. Despite these differences, the results were shocking.

Out of the 21 larvae tested, only 18 had DNA suitable for analysis. Out of these 18, all the larvae belonged to the same species of moth. Despite there being more than 60 species of larvae which are commonly consumed throughout Mexico, all 18 mezcal worms were found to be larvae of the comadia redtenbacheri moth.

“It’s relatively easy to broadly determine the kind of larva based on the shape of the head, but their identity has never been confirmed,” says Akito Kawahara, curator at the Florida Museum’s McGuire Center for Lepidoptera and Biodiversity, in a media release. “This is probably because most biologists are not looking inside mezcal bottles.”

“Our finding that all larvae are a single moth species affirms the importance of C. redtenbacheri for the mezcal industry,” study authors write in their study. “Larvae of C. redtenbacheri are one of the most popular edible insects in Mexico, and adding them to mezcal bottles brings about the unique color and flavor of the liquor.”

However, due to their popularity and medicinal qualities, Dr. Kawahara adds the larvae of these moths are in greater demand than ever, which is applying pressure to their populations. In order to halt the declining number of larvae — but not their inclusion in alcoholic drinks — researchers in Mexico have begun developing methods of cultivating these larvae in captivity.

South West News Service writer James Gamble contributed to this report.

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