Survival and Feed Non-Preference of Helicoverpa Armigera larvae in Varietyes of Landrace Maize

Abstract

Helicoverpa armigera is a major agricultural pest with a significant global impact, particularly in crops such as soybean and maize. Its ability to adapt to various plants and develop resistance to chemical insecticides and Bt proteins in transgenic plants makes its control a challenge. Integrated strategies, such as the use of resistant varieties of landrace maize, can offer sustainable solutions and reduce pesticide use. This study aimed to evaluate the survival and food consumption of H. armigera larvae in different genotypes of native corn and a commercial cultivar with Bt expression, focusing on resistance mechanisms such as antibiosis and antixenosis. Experiments were conducted in the laboratory using five corn genotypes (transgenic, Andean purple, red, Xavante, and purple straw). Resistance tests were developed in the laboratory, for the survival analysis, sections of corn leaves were offered ad libitum, and the death day of each individual was recorded, and the  data was analyzed by Weibull distribution to estimate the mean survival time. For the food consumption test, 2 cm² disks were offered from the basal part of the genotypes with a completely randomized experimental design with 5 replications with one larva per plot. The results of the survival analysis showed that the native genotypes approached the transgenic maize, suggesting moderate to high resistance. These findings indicate that genetic diversity in native corn genotypes significantly influences the survival and feeding behavior of H. armigera.