Biology of helicoverpa armigera (Hübner) (Lepidoptera: Noctuidae) rearing on artificial or natural diet in laboratory

Abstract

Background and Objective: Rearing insects in the laboratory is fundamental to solving problems related to basic and applied entomology. Helicoverpa armigera (Hübner) (Lepidoptera: Noctuidae) is considered as one of the most economically important pests for worldwide agriculture. Maintaining colonies of this insect in the laboratory allows advances in integrated pest management studies. The aim of this study was to evaluate different diets for H. armigera growth and successfully establish the growth of this lepidoptera-pest in laboratory conditions. Materials and Methods: The larvae of H. armigera were rearing in three diets. The egg and larva stages were kept in a heated room with a temperature of 28±2°C, UR of 60±10% and 14 h of photophase. Twenty-five couples per diet were individualized in cylindrical cages made of PVC pipe kept at 25±2°C, UR of 60±10% and 14 h of photophase. The data from larval stage were submitted to Kruskal-Wallis non-parametric analysis and the means were compared by Dunn method. Biological parameters of adults were submitted to one-way analysis of variance (ANOVA) followed by Tukey’s test. The viability of the different development stages were compared by Fisher’s exact test. The sex rate was submitted to the x2. Results: The artificial diets presented a higher viability in the stages egg, larva, pre-pupa and pupa and lower development period in regard to the natural diet. The shortest larval period was recorded on the chickpea-based diet. The pre-pupal period was similar in the diets evaluated. The moths that developed on the natural diet showed a longevity that was significantly less than on the other two diets. The pre-oviposition, oviposition and incubation of eggs periods did not present a statistical difference. The population would increase daily by 6, 5 and 3% on the chickpea, bean and green bean diet. Conclusion: The present study indicated that the artificial diets were more adequate for H. armigera and the chickpea-based diet resulted in a shorter generation time of H. armigera.