Host Suitability and Susceptibility of Major Stored Cereals to Rice Weevil Sitophilus Oryzae Linnaeus

Rice weevil (Sitophilus oryzae Linnaeus) is known to be the primary pest in stored rice, however various studies reveal that it also infests other major cereals in storage. To assess host suitability, a laboratory investigation constituting certain moderately tolerant varieties (to stored grain pests) of eight different stored cereals such as rice, wheat, sorghum, barley, oats, maize, pearl millet, and finger millet were evaluated in a completely randomised design during the year 2023–24, based on distinct biological growth parameters of the pest and the classification of resistance in the cereals to the rice weevil. Maize proved to be the most desirable host with the maximum oviposition duration (6.01 days), maximum fecundity (261 eggs/ female), maximum orientation index (10.78), weight loss (38.73%), adult emergence (65.09%), and growth index (1.66), recording the maximum susceptibility index (13.10). Rice was also highly susceptible (12.39). Comparatively, oats had the lowest oviposition (2.95 days), least fecundity (124.6 eggs/ female), lowered orientation (2.85), least weight loss (9.53%), lower emergence (39.05%), smallest growth index (0.56), and lowest susceptibility index (5.66), making it highly resistant. These findings categorically confirm maize and rice serve to be the most suitable hosts for S. oryzae, whereas oats exhibited highest resistance even among the moderately tolerant varieties of the tested cereals.