Response of four stored products insects to a structural heat treatment in a flour mill

Heat treatment is an ecologically sustainable technique that can be used as an alternative to chemical pesticides. The objective of this trial was the evaluation of efficacy of a commercial structural heat treatment, performed by means of electric heaters in a flour mill. Maximum temperatures, time above 50°C and to reach 50°C were different for each floor of the treated mill. Susceptibility to elevated temperature of different life stages of Tribolium confusum, Gnatocerus cornutus, Sitophilus oryzae, and Rhyzopertha dominica are reported. The mortality at 12, 24 and 36h after the beginning of the heat exposure was evaluated. Eggs of T.confusum were the most sensitive stage to heat treatment. For total effectiveness of the treatment, a time between 24 and 36h was necessary. The use of electric heaters could represent a viable alternative to other methods used for pest control in the milling sector.