Composition and Functional Groups of Insects in Grain Crops from South-Ern Guanajuato

Abstract

Eight samplings were carried out in three-grain crops; corn, wheat, and barley, in El Capulín, Salvatierra, Gto., collecting 6,596 specimens of insects, from August to November 2018 and from February to May 2019. The entomofauna is made up of 11 orders and 59 families, of which, 53 are in corn, 25 in wheat, and 24 in barley. The entomofaunal community is grouped into two functional groups according to their ecological role, and their diet: 1) EFG ́s (ecological functional groups), it includes herbivores, predators, parasitoids, pollinators, vectors, decomposers, and generalists; 2) TFG ́s (trophic functional guilds) comprise phytophagous, insectivores, decomposers, polyphages, Necrophagist, hematophagous, carnivores, nectarivorous, and mycophagy. The principal component analysis for the EFG ́s indicated a close relationship and dominance of herbivores and predators in corn, unlike wheat and barley, while for the phytophagic and insectivorous TFG ́s presented the same relationship. As far as it can be said that in maize cultivation, both functional and trophic relationships are established by antagonistic groups of plant hosts and predators, the other groups in wheat and barley being non-specific and generalist groups. This shows dominance of insects adapted to the development, growth, and phenology cycles in the corn crop, in which the abundance values denote a relationship with demographic factors typical of phytophages, and a smaller number of families of the other groups. The agronomic management and other ecological interactions in the agroecosystems are factors that contribute to the composition of functional groups for entomofauna in the grain crops studied.