Resumen
- Guava weevil, Conotrachelus psidii Marshall (Coleoptera: Curculionidae) is one of the major pests affecting guava cultivation in Santander-Colombia, resulting in severe fruit loss in terms of quality and quantity. In this study, efficacy of the entomopathogenic nematodes; Heterorhabditis indica SL0708 and Steinernema sp. JCL024, applied to greater wax moth cadavers and used to treat the 4th instar larvae of the guava weevil under greenhouse and field experiments was evaluated. Under greenhouse conditions, mortality rate ranged between 37 and 71% with H. indica SL0708 compared to Steinernema sp. JCL024, respectively. Field evaluation of H. indica SL0708 showed larval mortality rate between 84 - 91% after 21 days of treatment with insect cadaver concentrations of 4 or 6 individuals. Obtained data demonstrated that the highest rate of infection occurred during the 2-6 weeks of cadaver application. Although fruit damage is caused by early larval stage, the control by application of the nematode-infected cadaver was a plausible practice. This technique could be easily implemented by small growers at crop areas of 1 to 10 ha to reduce the guava weevil population in the region.