Pathogenicity of <i>Heterorhabditis bacteriophora</i> in Ultraviolet Light–Irradiated Agar Suspension on <i>Spodoptera frugiperda</i> (Lepidoptera: Noctuidae) Larvae1

Spodoptera frugiperda (J.E. Smith) (Lepidoptera: Noctuidae) is an economically important pest of variety crops, including maize (Zea mays L.), rice (Oryza sativa and cotton (Gossypium spp.). Conventional chemical insecticides are usually used for management this pest; however, a viable alternative the use microbial agents or their biological products, such as entomopathogenic nematodes. Their efficacy, affected by abiotic conditions ultraviolet (UV) light desiccation. It therefore necessary to develop formulations that preserve extend viability agent product while facilitating ease application. This laboratory study was conducted determine pathogenicity nematode Heterorhabditis bacteriophora (Poinar) against S. third-instar larvae. Infective juveniles (IJs) were tested at concentration 350 IJs/ml in two substrates (water 0.1% [w/v] agar suspension) with four periods exposure (0, 5, 10 15 min) UV radiation 253.7 nm. Each eight treatments included 40 larvae, each treatment replicated three times completely randomized design (two factors type medium time). We determined (w/v) suspension, compared water substrate, protected IJs from harmful thus improved survival frugiperda.