A mezcal worm is an insect larva found in some types of mezcal produced in Oaxaca, Mexico. The larva is usually either a gusano rojo ("red worm") or a chinicuil ("maguey worm"), the caterpillar of the Hypopta agavis moth.
The other variety of "worm" in mezcal is the larva of a weevil known as picudo del agave, Scyphophorus acupunctatus, the agave snout weevil, that infests the yucca plant and certain species of maguey. They are not related to edible maguey worms of central Mexico.
The weevil is a pest that can severely damage maguey and agave plants, although more by infecting the plant with harmful bacteria than damage done by the weevil or its larvae. In some cases, up to 40% of a maguey harvest has been lost to weevil infestations. Infection-resistant varieties of the plant are being developed.
Picudo larvae may be roasted and eaten; they are a seasonal specialty of markets in southeastern Mexico.
Although the custom is relatively recent, larvae are used frequently by several brands of mezcal to give flavor to the drink. A whole larva is deposited in the bottle, normally after having previously been cured in pure alcohol. Nacional Vinicola (NAVISA) was the first company to add a worm to its Gusano Rojo mezcal. Andres Paniagua and Jacobo Lozano, creators of Gusano Rojo and Dos Gusanos, first introduced the practice of adding larva to mezcal. Today there are several brands doing this.