The insecticidal potential of Metarhizium rileyi could be affected by thermal and hydric stress. In this study, 21 thermo-inductors were added to a fermentation medium to obtain thermotolerant conidia of M. rileyi Nm017. The first screening by a thermotolerance test concluded that using linoleic acid, NaCl, and menadione, conidia reached relative germinations higher than the treatment without inductors. Conidia produced with linoleic acid at 20 and 40 ml kg−1 showed relative germinations of 23.5% and 21.1% after the thermotolerance test, and their germination after a drying process was not affected compared to the control (80.2%). Manufactured costs using linoleic acid, NaCl, and menadione were estimated.