LAUSR

The commercial use of entomopathogenic nematodes after mass production requires the development of formulation techniques that extend nematode survival and prevent virulence loss during storage. In this study, the room temperature viability of Steinernema yirgalemense , in diatomaceous earth (DE), was investigated. The shelf life was maintained above 70% mean survival rate by week 4. To avoid microbial contamination, the direct effect of antifungal agents, peroxyacetic acid (PAA), trans-cinnamic acid (TCA) and nipagin on the efficacy of the infective juveniles (IJs) was preliminarily investigated. Short-term exposure of PAA lowered the efficacy of IJs, yet low concentrations of TCA and nipagin had no effect . Finally, the combined effect of DE and nipagin on IJ efficacy was assessed. High concentrations of nipagin in DE killed all the IJs in the first week of storage. Lower concentrations of nipagin in DE have potential to be incorporated in EPN products.