Abstract

Helicoverpa armigera caterpillar causes serious economic crop losses in Brazil, mainly in the corn, cotton and soybean farming. The aim of this study was to compare the efficiency of bioinsecticide Spinosad in the form of suspension capsules and emulsifiable concentrate in the dosage of 48 g i.a. ha^-1 for control of H. armigera. The experiment was conducted in three different groups treated separately with emulsifiable concentrate (EC) with 48% of spinosad; suspension capsules (SC) with 48% of spinosad; and control group treatment with deionized water. Caterpillars were used in the early stage (1 and 2 days old larvae), and maintained under laboratory conditions (24 ± 1°C, 65 ± 5% RH and a 12:12 h light: dark photoperiod). The mortality was recorded and the affected behavior of treated larvae was checked every 30 min for a period of 8 h. The results show the efficacy of spinosad for control of H. armigera in the emulsifiable concentrate group treatment at 92.6 and 88.9%, and in the suspension capsule group treatment at 88.9 and 87.0%, respectively, in the first and second bioassay. It was concluded that the spinosad 48 g i.a. ha^-1 is efficient in the control of H. armigera in micro encapsulated formulations, promoting less environmental damage by reducing the level of pesticides in the environment by the smaller concentration of the active ingredient through capsule suspension formulation and revealed economic viability and promotion of extended release of active ingredients.

Key words: Industrial biotechnology, biological control, biopesticide, caterpillar control, microcapsules, emulsifiable concentrate.