Evaluation of Efficacy, Residual and Knock Down Effects of Pretransplant Applications of Nicotinoid and Nicotinoid-Pyrethroid Insecticide Mixtures for the Control of Myzus persicae nicotianae (Hemiptera: Aphididae) on tobacco

Eduardo Fuentes-Contreras1*, Esteban Basoalto1, Claudio Sandoval1, Patricia Pavez1, Claudia Leal1, Raúl Burgos1 y Cristián Muñoz1

Pretransplant applications of imidacloprid, acetamiprid and thiamethoxam, and a mixture of imidacloprid and cyfluthrin were evaluated on tobacco (Nicotiana tabacum L.) seedbeds for the control of the aphid Myzus persicae nicotianae Blackman. Corrected mortality at 48 h after aphid release on plants in a seedbed was over 80% almost permanently up to 75 days after application (DAA) with a dose of 14 g a.i. m-2 seedbed of imidacloprid. In another experiment, the same level of corrected mortality was maintained by doses of 5.6 g a.i. m-2 seedbed of acetamiprid and 7 g a.i. m-2 seedbed of thiamethoxam up to 50 and 30 DAA, respectively. After 30 DAA for all the insecticides evaluated in both experiments, corrected mortality at 24 h was lower than at 48 h after aphid release on treated plants, which shows a limited knock down effect of these treatments. Finally, in another experiment a mixture of 10.5 and 0.21 g a.i. m-2 seedbed of imidacloprid and cyfluthrin, respectively, showed a good knock down effect, with corrected mortality higher than 80% up to 70 DAA at 48 h and without significant differences with corrected mortality at 24 h after aphid release on plants.

Key words: imidacloprid, thiamethoxam, acetamiprid, cyfluthrin.

1 Universidad de Talca, Facultad de Ciencias Agrarias, casilla 747, Talca, Chile. E-mail: efuentes@utalca.cl *Corresponding author

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