Acaricidal Efficacy of Diatomaceous Earths on Different Life Stages of Acarus siro L. and Tyrophagus putrescentiae (Schrank)

<i>Acarus siro</i> L. and <i>Tyrophagus putrescentiae</i> (Schrank) (Sarcoptiformes: Acaridae) are cosmopolitan mite species in food storage and processing environments, infesting a wide variety of commodities. In the current study, the diatomaceous earths (DEs) InsectoSec and Fossil Shield were evaluated for wheat protection against adults, larvae, and nymphs of <i>A. siro</i> and <i>T. putrescentiae</i>. Both DEs were examined at 200 and 500 ppm at 1, 2, and 5 days post-exposure. The efficacy of both formulations against <i>A. siro</i> and <i>T. putrescentiae</i> life stages depended on dose and exposure. Mortality of <i>A. siro</i> reached 100% in larvae, 99.3% in nymphs, and 95.6% in adults by day 5 at 500 ppm of InsectoSec. Similarly, Fossil Shield achieved almost complete larval mortality (99.3%) of <i>A. siro</i> at 500 ppm. For <i>T. putrescentiae</i>, 100% mortality was observed for larvae at both doses of InsectoSec and for adults or nymphs at 500 ppm by the fifth day. Fossil Shield caused a similar mortality to larvae, reaching 97.0% and 100%, at 200 and 500 ppm, respectively, after 5 days. Our findings indicate that InsectoSec and Fossil Shield can be used as sustainable management tools against <i>A. siro</i> and <i>T. putrescentiae</i>.