Edible use and nutritional composition of Corydalus larvae (Megaloptera) in Oaxaca, Mexico

Abstract Entomophagy is increasingly recognized both as a culinary tradition and as a sustainable alternative protein source. In Mexico, most research efforts have focused on terrestrial edible insects, while aquatic insects, such as Megaloptera, remain largely understudied. Through interviews and morphological identification, we documented the edible use of Corydalus larvae by an ethnic group in Oaxaca, Mexico. In addition, to assess the water quality in the river where the larvae develop, we determined its physical and chemical parameters through in situ measurements and standardized colorimetric tests. The proximate composition of the larvae was evaluated to determine their protein, fat, fibre, and carbohydrate content. We provide the first record of edible use of Corydalus larvae in a Zapotec community in the Sierra Norte of Oaxaca. Water quality analyses indicated that physicochemical parameters including pH, dissolved solids, conductivity, and inorganic compounds were within the safe ranges for freshwater bodies in tropical climates, complying with Mexican regulatory limits. The proximate composition of Corydalus larvae showed a protein content greater than 35% on a dry basis, with lipids and carbohydrates representing above 13% each and a moderate amount of fibre content (approx. 12%), demonstrating a balanced nutritional profile. The estimated energy content (382 kcal/100 g DM) confirms its potential as a food source. These results position Corydalus larvae as a sustainable protein alternative with high nutritional value compared to conventional foods of animal origin.