Biological aspects of Tetranychus ludeni Zacher, 1913 (Acari: Tetranychidae) fed on sweet potato leaves sprayed with 2,4-D

Abstract

Sweet potato [Ipomoea batatas (L.) Lam.] presents great versatility of uses in Brazil. With the expansion of crop areas, this species is subject to contamination by herbicides. Eventually, non-target organisms can be exposed to residues . The aim of this study was to evaluate biological aspects of the mite Tetranychus ludeni fed on sweet potato leaves sprayed with different doses of the herbicide 2,4-D. The experiment was conducted at the Biological Control Laboratory of Universidade Federal dos Vales do Jequitinhonha e Mucuri (UFVJM), Diamantina, Minas Gerais, Brazil. Altogether, 175 females of T. ludeni and six doses of 2,4-D, in g.ha-1 (8.06, 20.15, 40.30, 80.60, 201.50, and 806,00) were used, plus the control done with distilled water. It was adopted a completely randomized design with seven treatments and five replications with five females each. Early mortality of T. ludeni (24 h), the number of eggs, nymphs and longevity of females were evaluated. Data were subjected to analysis of variance, being the significant mean analyzed by Duncan test. It was observed that high doses of the herbicide may increase the mortality and decrease longevity of females of T. ludeni.