It is recorded the occurrence of Pyemotes tritici (Lagréze-Fossat & Montagné) on Cathartus quadricollis (Guérin-Méneville) and Callosobruchus maculatus (Fabricius), reducing insect s populations in laboratory conditions. This mite was observed feeding on larvae and pupae of C. quadricollis, and adults of C. maculatus. The mite toxin quickly paralyzed larvae and adults attacked. The mite P. tritici is a lethal problem for mass rearing of insects and its effective eradication ultimately depends on the periodic monitoring of the insect colonies. As result, the mite P. tritici can be a new alternative for the biological control of C. quadricollis and C. maculatus in stored products. However, this possibility must be better understood before it could be recommended, because Pyemotes sp. could also cause dermatitis in the humans.