Alternative synergistic for acetylcholinesterase inhibitors insecticide.
The importance of the use of synergists is related to the minimization of the amount of chemical insecticide necessary for the control of insects, and can contribute to the reduction of environmental contamination and the preservation of beneficial insects. Thus, the objective of this work was to evaluate the synergistic and homogeneous response effect of Spodoptera frugiperda caterpillars (JE Smith, 1797) to sublethal doses of the essential oil of Piper aduncum L. (OEPA) in combinations with organophosphorus formulations And carbamate, compared to those with piperonyl butoxide (PBO). Synergism factors (FS) were obtained to compare the treatments with each other. By residual contact, the insecticides Profenofos (FS=5.4-7.7), Phenitrothione (FS=3.9-29.2) and Chlorpyrifos (FS=3.4-7.8) were significantly potentiated. On the other hand, there was a significant increase in insecticides: Profenofós +1/4 of the LD50 of the OEPA (FS=5.4), Fenitrothione +1/4 of the LD50 of the OEPA (FS=33.8) and Chlorpyrofos +1/2 of the OPA (FS=2.5). Methomyl was not synergized by OEPA in the two contamination pathways and did not present increased selection pressure for resistance in the evaluated population of S. frugiperda caterpillars. It was not possible to conclude on the homogeneity of response and the selection pressure with respect to the organophosphate insecticides for S. frugiperda. The results indicate that Piper aduncum essential oil has synergistic potential for Fenitrothione, Profenofos and Chlorpyrifos and may be an alternative to piperonyl butoxide.