The objective of this work was to evaluate the insecticidal effect or repellency of Cyperus rotundus, an important weed plant, through alternative methods of extraction, on Diabrotica speciosa, a pest that affects several plant species. The experimental design was completely casual, and consisted of five repetitions. The C. rotundus extracts were prepared using leaves and roots by alcoholic extraction, aqueous (hot water) extraction and aqueous (cold water) extraction and diluted to four different concentrations (0, 5, 10, and 15% of the volume of each extract). These dilutions were then tested and compared with a control. The higher mortality of D. speciosa adults as well as a smaller leaf consumption area were observed after treatments with increasing dosages of different C. rotundus extracts generated by alcoholic extraction (55% of mortality and 28% leaf consumption). Therefore, the alcoholic extract of the C. rotundus foliage is an option for the control of D. speciosa in agroecologic systems.
rootworm; nutgrass; Chrysomelidae; alternative control
