Quinoa is an Andean grain that is increasingly gaining international attention. In recent years, the crop has also emerged in Peruvian regions at lower altitudes (including the Coast). This study investigated the insect diversity associated with quinoa by collecting insects with pitfall traps throughout the crop phenology in three altitudinal zones of Peru: San Lorenzo, in the traditional production region, Junín; and Majes and La Molina in the non-traditional regions Arequipa and Lima, respectively. Our data revealed that the alpha diversity (in terms of species evenness and species richness) was highest in the Andean zone, San Lorenzo, and lowest in Majes. As to the functional groups (herbivores and natural enemies), no differences between field sites in species evenness were found but San Lorenzo was significantly superior to the other zones in species richness of both functional guilds. The analysis of beta diversity revealed large differences among field sites in terms of entomofauna composition, with few species in common; the key pest of quinoa in South America, Eurysacca melanocampta, was found at the three localities. The results of this study can contribute to a more sustainable pest management system taking into account insect-mediated ecosystem services like biological control.