Durum Wheat Cultivars Express Different Level of Resistance to Granary Weevil, Sitophilus granarius (Coleoptera; Curculionidae) Infestation

The granary weevil, Sitophilus granarius Linnaeus 1875, is a primary pest of stored grains worldwide. Feeding damage and progeny production of S. granarius was estimated to identify the levels of resistance of the insect on different durum wheat cultivars. Insect attack on four different durum wheat cultivars was investigated over a period of 20 weeks. Durum wheats were artificially infected with 20 individuals of S. granarius. Every two weeks the sample weight, hectoliter weight, moisture and the number of live weevils, including their number of progenies, were recorded. Overall findings revealed different levels of resistance of different durum wheat cultivars to S. granarius infestation. The Primadur cultivar had the highest resistance, followed by the Marco Aurelio and Cesare cultivars followed finally by the Tito Flavio cultivar which was highly susceptible to S. granarius. For all cultivars, apart from Primadur, S. granarius metabolism increased humidity and temperature, leading to grain degradation and resulting in the potential complete loss of market value if under field conditions. Evidently, durum wheat characteristics affect the life cycle of S. granarius, primarily their progeny, and thus the damage they undertake to the wheat itself. These findings are important because they enable the strategic selection of wheat cultivars that can be stored for a longer time period, while more sensitive wheat cultivars can be selected for shorter storage time and thus faster delivery to market.