Individual and Integrated Applications of Entomopathogenic fungi (EPFs) and Biopesticides against Leucinodes orbonalis (Lepidoptera: Crambidae): From Laboratory Insights to Field Evaluations

Abstract

Leucinodes orbonalis (Guenee) is a notorious pest of brinjal crop inflicting severe economic losses due to its cryptic feeding behavior and resistance development against chemical insecticides. The current study evaluated the individual efficacy of Beauveria bassiana Balsamo (Vuillemin) and Metarhizium anisopliae (Metschnikov) Sorokin against two larval instars (3rd and 5th) and pupal stage of L. orbonalis under laboratory conditions. Later, the pathogenicity of most virulent fungal species was also assessed in combination with two biopesticides under field settings. The results revealed that both the tested fungal species showed pathogenicity against different immature stages of L. orbonalis. However, more pronounced results were achieved in case of B. bassiana. Moreover, the early larval instar (3rd) showed more vulnerability against the tested fungal species as compared to later instars. The percent mycosis and sporulation rates in dead cadavers of insects were significantly higher at lower fungal concentration. The results pertaining to field experiment revealed the integrated applications of tested experimental treatments (B. bassiana + biopesticides) significantly performed better than their individual counterparts. The study outcome advocates the integration of EPFs and biopesticides as a viable option not only to manage L. orbonalis, but also to mitigate pesticide residues in brinjal crop.