Essential oil (EO) nanoemulsion is a new approach to formulate and convey insecticides and to minimize some of the common shortcomings associated with the conventional formulations of synthetic insecticides and also of essential oils. The aim of the present was to develop an oil-in-water (O/W) nanoemulsion of the essential oils of chamomile (Matricaria chamomilla L.) and cumin (Cuminum cyminum L.), and assess their lethal and sublethal toxicity to the red flour beetle Tribolium castaneum (Hersbt).  The nanoemulsions of EO were characterized by droplet sizes of 341.4 and 387.1 nm for the chamomile and cumin, respectively. The polydispersivity (PDI), viscosity (cP), zeta potential (mV) and conductivity (mS/cm) of the nanoemulsions were also characterized. The cumin nanoemulsion exhibited higher lethal toxicity to the flour beetle, besides of compromising the insect weight gain while impairing their food consumption and conversion rate in sublethal exposure. Cumin EO nanoemulstion also sparked anti-feeding activity, reduced progeny production and prevented grain weight loss by the red flour beetle indicating its potential for stored product protection.