VARIATION OVER TIME OF BIOINSECTICIDES EFFECT ON Spodoptera frugiperda INCIDENCE IN CORN (Zea mays) IN DRY SEASON IN MOCACHE, LOS RÍOS, ECUADOR

Abstract

<p><strong>Background.</strong> Corn cultivation – one of the main crops in the world – is important in Ecuador for human and animal nutrition, but one of the main limitations in production is the damage caused by the insect pest <em>Spodoptera frugiperda</em> (J.E. Smith) (Lepidoptera: Noctuidae). <strong>Objective</strong>. Therefore, the objective of this research is to evaluate the effectiveness over time of three bio-insecticides on pest incidence in maize hybrid INIAP H601 in Mocache, Los Ríos, Ecuador in the dry season. <strong>Methodology</strong>. A completely randomized design was used with five treatments and four replicates: (1) Natural neem (<em>Azadirachta indica</em>) leaf extract in doses of 1.88 L; (2) Bassigeos (<em>Beauveria bassiana</em>) in doses of 5 L; (3) Neem + <em>B. bassiana</em> mix in doses of 7 L; (4) Chemical bait in doses of 80 kg.ha<sup>-1</sup>; and (5) Control group without application, processed by a linear model of repeated measures. <strong>Results</strong>. A significant variation was observed in the treatments due to the influence of time. <strong>Implications</strong>. Corn agricultural production has a long tradition and importance in Ecuador, especially in the Province of Los Ríos where productions are affected by <em>S. frugiperda </em>whose major control is by using polluting chemical products. <strong>Conclusions</strong>. Because the effect of the applied bio-insecticide treatments changes overtime, pest incidence is modified through a linear model of repeated measures. The lowest incidence percentages are achieved with the use of <em>B. bassiana </em>(Bb), <em>A. indica</em> (neem) and Bb + Neem mix after day 15, whereas the chemical control group achieves it throughout the evaluated time interval.</p>