The municipality of Salvatierra, in Guanajuato, Mexico, develops an agricultural activity of national and regional importance. However, despite this, there needs to be more information on ecologically and economically important faunal groups, such as insects. Therefore, the objective of this study was to have an approximation of the entomofauna in four crops: sorghum, alfalfa, maize, and beans, as well as their composition and the characterization of the functional groups of insects in a dry seasonal tropical environment of the municipality of Salvatierra. The entomofauna for the four crops is composed of nine orders: Coleoptera, Diptera, Dermaptera, Hemiptera, Hymenoptera, Lepidoptera, Mantodea, Neuroptera, and Orthoptera, and 53 families. The highest Simpson Wealth Index value was for alfalfa (0.91) and the lowest for beans (0.84). On the other hand, in terms of its structure and composition, the entomofauna is represented by eight functional groups: Herbivores = H, Predators = D, Parasitoids = PAR, Pollinators = POL, Vectors = V, Decomposers = DES, Xylophages = XIL, and Generalists = G. Phytophagous insects (pests), predators and parasitoids are the most common and abundant in crops. The present work generates new data on the entomofauna present in the agroecosystems of the community of Urireo in the municipality of Salvatierra, Guanajuato state, informing the development of specific studies of demography and ecological interactions between insect-plant and insect-insect.