Evaluation of the Effect of Different Concentrations of Spirotetramat on the Diaspine Scale Parlatoria ziziphi in Citrus Orchards

Abstract

The control of Parlatoria ziziphi (Lucas, 1853) was studied in citrus orchards at Mechraa Belksiri in the Gharb area of Morocco. Three concentrations of spirotetramat T0 = 0 L/Ha as a control experiment, T1 = 0.625 L/Ha, T2 = 0.755 L/Ha, and T3 = 1 L/Ha, were applied on 4 ha of Valencia late orchard (each dose for 1 ha of Valencia late). The effect of spirotetramat was evaluated on the mortalities and survival rates of P. ziziphin during the stages of larvae (first instar and second instar) and females (F1, F2, and F3). Results showed that the spirotetramat was effective on larvae and females of P. ziziphi. Among the 11,229 females recorded, 93% were inhibited, while only 7% were intact after the treatment period. Finally, our study highlights that all concentrations tested were effective on the P. ziziphi population; besides, all three concentrations of this product tested were equally effective on larvae and females of P. ziziphi. Thus, during the spread period, spraying a low concentration of this product (0.625 L/Ha) will better control this pest and reduce the environmental impact.