Entomofauna asociada a cinco variedades de alfalfa (Medicago sativa) bajo riego y secano en una zona altoandina de Perú

The objective of the study was to determine the diversity and abundance of the entomofauna associated with five varieties of alfalfa (Medicago sativa) under normal irrigation and deficit irrigation conditions. The varieties studied were Cuf 101, Alfamaster, Moapa 69, Hortus 1001 and California. The insects were collected using the sweeping technique, in seven-day intervals, from emergence to the first cut of the crop. A total of 4375 specimens were collected. They were distributed in eight taxonomic orders, eleven families and fourteen genera. The order Coleoptera was represented by two families and four genera; Hemiptera, by four families and five genera; and the orders Diptera, Orthoptera, Lepidoptera, Hymenoptera and Neuroptera, by one genus each. In each phenological phase the highest abundance was recorded in the flowering and maturation stage. Five phytophagous genera (Acyrthosiphon, Aphis, Schistocerca, Polites and Conoderus) and eight beneficial genera (Toxomerus, Coccinella, Harmonia, Cycloneda, Coranus, Zelus, Polistes and Chrysoperla) were found. The Cuf 101 and California varieties with normal irrigation harbored the greatest entomological richness. The most representative order was Diptera and the most abundand family was Syrphidae (Hemiptera predators).