Inert powders alone or in combination with neem oil for controlling Spodoptera eridania and Spodoptera frugiperda (Lepidoptera: Noctuidae) larvae

Abstract

Laboratory studies was carry out to evaluated the potential of inert powders: bentonite, kaolin and diatomaceous earth (DE) applied as dust and aqueous suspension alone and associated with neem oil to the control Spodoptera eridania and Spodoptera frugiperda second instar larvae. In dust applications, 100% mortality of S. eridania, at the concentrations of 1.5 and 2.0 grams of bentonite, and 93.3% of S. frugiperda, at the concentration of 2.0 g were observed. DE at the height concentration (2.0 g) caused 76.2% mortality of S. eridania and 46.6% of S. frugiperda. Kaolin, in all concentrations, was the only treatment that did not differed from the control for S. eridania but was different, in the high concentration, for S. frugiperda. When the plants were treated, larvae of S. eridania fed in the treatment DE, had an increase of two days in larval period. For the sex ratio, the percentage of males was greater in the treatments with kaolin, for both species. When powders was applied suspended in water separately or combined with neem oil, the best results were observed in combined of the bentonite (10%) + neem, with 100% mortality for both species, and kaolin (10%) + neem with 78.5% and 95.6% mortality for S. frugiperda and S. eridania, respectively. These treatments were classified as non-additive synergistic.