Estimating the Susceptibility of Four Wheat Cultivars to the Saw-Toothed Grain Beetle Oryzaephilus surinamensis (L.) (Coleoptera: Silvanidae)

The quality and quantity of wheat are severely affected by insect infestation during storage. Excessive use of chemical pesticides has resulted in several environmental issues, in addition to the emergence of pesticide-resistant strains. Extensive research has been conducted to determine sustainable alternatives, such as the selection and cultivation of insect-resistant crop varieties. The aim of this study was to determine the degree of susceptibility of four wheat cultivars, namely, Albelad, Aldwasair, Australia, and Najran (NJ), to Oryzaephilus surinamensis (L.) using four parameters: F1 progeny, length of developmental period, Dobie's index of susceptibility (DI), and percentage weight loss (PWL). Albelad was highly susceptible (DI =17.44) to O. surinamensis, followed by Najran (DI =8.42) and Australia (DI =6.18) (susceptible and moderately susceptible, respectively), whereas Aldwasair was moderately resistant (DI =4.67). Furthermore, there were significant positive correlations between DI and the mean number of F1 progeny (R(2) = 0.98) and between DI and grain weight loss (R(2) = 0.95). However, a significantly negative correlation (R(2) = −0.86) was observed between DI and beetle developmental period. These findings will aid the development of breeding programs to maintain the quality and quantity of wheat grains during storage.