Efecto in vitro del extracto de Clinopodium tomentosum para el control de Eotetranychus lewisi y Oligonychus coffeaee (Acari: Tetranychidae)

Abstract

The Tetranychidae family contains more than 1,300 species, including more than 100 economically important species due to the economic losses. Oligonychus coffeae and Eotetranychus lewisi were recently registered in Ecuador associated with forest species and different agricultural crops, respectively. Given the importance of the Tetranychidae species in the present study, the in vitro effect of the Clinopodium tomentosum extract was evaluated for the control of Eotetranychus lewisi and Oligonychus coffeae (Acari: Tetranychidae). The effect of different concentrations (0, 1, 2, 4, 8 and 16%) of the ethanolic extract of C. tomentosum on the mortality, oviposition rate and longevity of the females of these mite species was evaluated using the residual contact technique. in rearing units. Mortality evaluations were made 24, 48 and 72 h after application, while oviposition and longevity were determined until female death by sublethal effect. An increase in the mortality rate in females of O. coffeae and E. lewisi was observed as the concentration of the extract of C. tomentosum increased. In O. coffeae, the highest mortality in was reached with concentrations of 8 and 16%, with which 50% mortality was reached, while in E. lewisi, the mortality rate reached 60%. Both in O. coffeae and E. lewisi females, the oviposition rate decreased as the extract concentration increased, mainly from the 4% concentration, which caused a 38.6% decrease in relation to the treatment. control, while with the doses of 8 and 16%, oviposition was reduced by up to 55.6 and 65.8%, respectively. Likewise, a negative relationship between longevity and dose was observed, that is, as the dose of the extract increased, a decrease in longevity was shown in both species of mites, being more noticeable with higher doses (4- 16%) for the case of O. coffeae, while with E. lewisi the reduction was observed with concentrations greater than 2%. Based on the results obtained, the use of the ethanolic extract of C. tomentosum could be included in population management programs for Oligonychus coffeae and Eotetrany