Universidade Federal Rural do Semi-árido, Revista Caatinga, 2(32), p. 354-363, 2019
DOI: 10.1590/1983-21252019v32n208rc
Full text: Download
ABSTRACT The present study aimed to assess the effects of the essential oil of Croton pulegiodorus Baill on eight populations of Sitophilus zeamais Motschulsky with different patterns of susceptibility to synthetic insecticides. Populations of S. zeamais were obtained from Sete Lagoas-MG, Jacarezinho-PR, Bom Conselho-PE, Garanhuns-PE, Jupi-PE, Lajedo-PE, São João-PE and Serra Talhada-PE. To estimate the lethal concentrations (LC50 and LC90) of oil for each population, fumigation tests were performed. The susceptibility of S. zeamais to the essential oil varied among populations. Garanhuns and Bom Conselho was considered the susceptibility patterns, presenting the lowest LC50 (3.40 μL L-1 of air) and LC90 (9.60 μL L-1 of air) for the essential oil, respectively. The population from Jupi exhibited the highest LC50 (14.49 μL L-1 of air) and LC90 (19.60 μL L-1 of air) for C. pulegiodorus. The resistance ratio ranged from 1.84 for the São João to 4.26 for the Jupi population. Thus, the essential oil of C. pulegiodorus showed fumigant activity, causing mortality in all S. zeamais populations used.