Diatomaceous earth and oil enhance effectiveness of Metarhizium anisopliae against Triatoma infestans

► DE delayed but did not reduce in vitro germination of M. anisopliae conidia. ► DE did not hamper the survival of T. infestans nymphs. ► The settling behavior of nymphs depended on the concentration of DE and light level. ► Conidia formulated with DE and oil quickly killed all treated insects, even at 75% RH.