A groundbreaking genetic study has finally unraveled the mystery of the worm found inside mezcal bottles. While speculation had ranged from butterflies to weevils, DNA analysis has revealed that all sampled larvae originate from a single moth species, Comadia redtenbacheri. This insect is not only a traditional delicacy in Mexico but is also believed to offer health and even aphrodisiac benefits.
The Mystery of Mezcal’s Worm
A recent study published in PeerJ Life & Environment aimed to determine the exact species of larva that ends up in bottles of mezcal. Mezcal, a distilled spirit made from agave, is often accompanied by orange slices and worm salt—a seasoning blend of chili peppers, salt, and crushed larvae from a moth species known as Hypopta agavis.
For decades, there has been considerable debate over the true identity of the so-called “mezcal worm.” Are drinkers consuming the larva of the skipper butterfly Aegiale hesperiaris, or the moth Comadia redtenbacheri, a species thought to have declined in recent years? Could the worm actually be a type of weevil, or perhaps an insect that has not yet been identified? To address these questions, scientists analyzed the DNA of larvae found in 21 different brands of mezcal sold commercially.
Collecting the Specimens
The larvae were collected from mezcal bottles purchased between 2018 and 2022. At first glance, they all appeared nearly identical, featuring a defined head capsule and prolegs typical of caterpillars. Some were pale white, while others exhibited a pinkish-red tint. Out of the 21 samples, DNA was successfully extracted and sequenced from 18.
DNA Evidence Revealed
The findings took researchers by surprise. Mexico has a long tradition of consuming insect larvae, with more than 60 species commonly eaten, including the Tequila giant skipper (A. hesperiaris), whose name suggests it might also appear in tequila and mezcal.
Instead, the genetic analysis confirmed that every larva tested belonged to a single moth species, Comadia redtenbacheri. This discovery underscores the significance of C. redtenbacheri not only as an iconic part of mezcal culture but also as one of the most widely consumed edible insects in Mexico.
The practice of adding larvae to Mexican beverages and foods—such as salts, garnishes, and powders—is driven by perceived health benefits and beliefs in their aphrodisiac properties. This trend is increasing demand, which is putting pressure on local larval populations.
Implications and Future Directions
In response to the declining numbers of mezcal larvae, researchers have started developing methods to cultivate these larvae in captivity. This move could help sustain the cultural and economic practices surrounding mezcal while protecting the natural population of Comadia redtenbacheri.
For more on this research, see “Scientists Discover the Unexpected True Identity of ‘Tequila’ Worms.”
Reference: “Mezcal worm in a bottle: DNA evidence suggests a single moth species” by Akito Y. Kawahara, Jose I. Martinez, David Plotkin, Amanda Markee, Violet Butterwort, Christian D. Couch, and Emmanuel F.A. Toussaint, 8 March 2023, PeerJ. DOI: 10.7717/peerj.14948
A version of this article was initially published in March 2023. Never miss a breakthrough: Join the SciTechDaily newsletter.
