MANAGING OF CATERPILLAR RESISTANCE TO BENZOYLPHENYLUREAS USING VEGETABLE SYNERGIST

Abstract

The fall armyworm, Spodoptera frugiperda (J. E. Smith, 1797) (Lepidoptera: Noctuidae), is a polyphagous species that feeds cultivated plants throughout in many areas of the American continente. In Brazil, the damage caused by this pest to maize crop ranges from 20 to 100%. The reliance on pesticides to control fall armyworm has led to the development of insecticide resistance in many world regions. The insecticides of the benzoylphenylurea group, lufenuron e triflumuron, have been successful in controlling the fall armyworm. However, the intensive use of this insecticide may reduce their efficiency owing to the evolution of resistance. Oil rich in dillapiole, obtained from Piper aduncum L. plants (OEPA), abundant in the Amazon, is an option to produce synergistic lignans.The objective of this work was to evaluate the synergistic effect agaist this pest to sublethal doses of the OEPA (0.24 e 0.12 x10^-4 µL mg insect^-1) in combinations with lufenurom and triflumuron, in topical and ingestion bioassay. In the topical application, there occurred significant synergism factors (FS) only for the insecticide lufenuron when combined with the sublethal doses of the OEPA (FS= 9.4 and 3.8; respectively). In ingestion bioassays  artificial diet containing triflumuron (1% e 0,001% v.v-1) and lufenuron (3% e 0.03% v.v-1), combined with the sublethal dose of the OEPA reduce the TL₅₀ of the larvae up to 22:18  and 29:36 hours respectively. The present study has demonstrated the high efficacy of synergism the OEPA for lufenuron and triflumuron insecticides.