Evaluation of indoxacarb and rynaxypyr against the corn earworm, Heliothis (Helicoverpa) zea, on fresh ears

Jaime E. Araya^1*, Francisco Zuazúa², Elizabeth Biscarra²

ABSTRACT

A field trial was conducted in order to evaluate the insecticides indoxacarb and rynaxypyr and compare their effects to a standard treatment of lambdacyhalothrin against corn earworm, Heliothis (Helicoverpa) zea (Boddie), a severe pest on fresh corn. These products did not cause repellence or inhibition in egg laying of Heliothis zea in all evaluation dates, that is, they neither influenced the number of eggs per ear nor the percentage of plants with eggs. The standard insecticide lambdacyhalothrin was the most effective treatment, as it obtained the least percentage of damage by Heliothis zea in the grains, and the least penetration percentage of larvae to the ears. The scale of damage used herein did not allow to differentiate statistically the results of larval damage between treatments. The application of indoxacarb or rynaxypyr obtained average levels of control of H. zea larvae on fresh corn. The plots treated with lambdacyhalothrin presented high mortality of the egg predator Orius insidiosus Say, and it should not be recommended in integrated pest management, differently from indoxacarb and rynaxypyr, which caused lower mortality, similar to those observed in the untreated control.

Key words: Heliothis zea, indoxacarb, Orius insidiosus, rynaxypyr.

¹ Departamento de Sanidad Vegetal, Facultad de Ciencias Agrarias, Universidad de Chile, Casilla 1004, Santiago, Chile.

² Escuela de Agronomía, Universidad Mayor, Casilla …, Santiago, Chile.

* Corresponding author E-mail: jaimearaya@yahoo.com