EFFECT OF DIFFERENT FORMULATIONS OF METARRHIZIUM ANISOPLIAE-BASED INSECTICIDE ON ITS EFFECTIVENESS AGAINST SPODOPTERA FRUGIPERDAON CORN

The fall armyworm (FAW) (Spodoptera frugiperda (J.E. Smith) (Lepidoptera: Noctuidae) is one of the most catastrophic pests of corn, the third most important food crop worldwide. In 2019, the pest was first recorded in Indonesia. Currently, the pest has been reported causing damaged to corn crops in most provinces of the country. Farmers depend primarily on insecticide use to manage the new invasive pest. To avoid the potential negative impacts of insecticide use, alternative control measures should be developed, including biological control. Fungal entomopathogen, Metarrhozium anisopliae, has been used as an effective mycoinsecticide against the pest in other countries. Formulation is very important to be considered in developing a new bioinsecticide because it affects the effectiveness, sporulation rate, and conidial viability of the entomopathogen. Thus, the study objectives were to determine larval mortality of S. frugiperda applied with different formulations of M. anisopliae. In addition, conidial density and viability of M. anisopliae in different formulations and incubated at different temperatures were also evaluated. The results showed that Metarrhizium anisopliae, prepared in powder formulation had better qualities in comparison to those cultured in pellet and pasta formulations. The fungus cultured on rice powder had higher pathogenicity against S. frugiperda larvae. Ten days after powder formulation was applied, 76% of the treated insects died, which was significantly higher than the percentages of dead insects in pellet and pasta formulations (56 and 52%, respectively). Similarly, conidial density was significantly higher for powder (5.21 x 106 conidia/ml) than pellet (2.79 x 106 conidia/ml) and pasta (0.85 x 106 conidia/ml) formulations. The percentages of the treated larvae becoming pupa were 11, 21, and 22% for powder, pellet, and pasta, respectively. Therefore, the powder formulation should be used in proliferation of the fungus in mycoinsecticide production.