Avaliação do potencial de extratos de plantas da caatinga no controle do ácaro-vermelho do pinhão manso

Abstract

Biodiesel production has received enough encouragement and among the crops with potential applicability to this highlights the physic nut (Jatropha curcas L. ) , which has been identified as one of the most promising crops for biodiesel and inclusion in family production chain , which has opened up broad prospects for growth in the areas of planting this crop in semi-arid northeast . Several factors limit the productivity of Jatropha, with emphasis on the attack by pests such as spider mite Tetranychus bastosi Tuttle , Baker & Sales (Acari : Tetranychidae) . Among the methods currently used for alternative pest control is gaining prominence employment of plant extracts due to the presence of secondary metabolites present in some plants and their low toxicity to the environment and to humans . In the present work we evaluated the potential of plant extracts Myracrodruon urundeuva All Br ( Anacardiaceae ) , Croton blanchetianus Baill (Euphorbiaceae) and Ziziphus joazeiro Mart . (Rhamnaceae ) on the mite T. bastosi associated with the culture of Jatropha. We evaluated the effect of the extract of M. urundeuva at different doses (0 , 5 % , 10 % , 15 % , 20 % and 25 % ) on the biology and fertility life table T. bastosi . It was observed that the extract of M. urundeuva prolonged cycle of development of the mite and with increasing dosages, prolonged the longevity of T. bastosi . With respect to the life and fertility table, it was found that there was no effect of the extract for the parameters, except for the survival and viability of eggs, where there was a lower progeny survival at a dose of 10% and a lower egg viability in strengths of 15 % and 20 %. Toxicity and repellency of the extracts of M. urundeuva , C. blanchetianus and Z. joazeiro was also evaluated . Generally extracts showed toxic effect on adults of T. bastosi the concentrations tested. The extract of Z. joazeiro showed the highest mortality rates (90 %) mean mortality of individuals. With regard to the repellency of these extracts, all treatments were shown repellents for females of Tetranychus bastosi classified as repellent treatment, except for the 5% dose of extract of M. unrundeuva .