Life history and life table parameters of the rice weevil, Sitophilus oryzae L. (Coleoptera: Curculionidae) fed on 10 rice cultivars and lines in Iran

The rice weevil, Sitophilus oryzae L. (Coleoptera: Curculionidae), is one of the most destructive pests of stored cereal grains globally. We evaluated the resistance of different rice cultivars (Anam, Gilar, Hashemi, Keshvari, Rash, and Tisa) and lines (8608, MN-7, TH-1, and TH-2) using life history and life table parameters of S. oryzae at 28 ± 1 °C, 70 ± 5% relative humidity, and complete darkness. The immature survival of S. oryzae ranged from 37% on Rash to 82% on Hashemi. The developmental times on tested rice cultivars and lines were significantly shortest on Hashemi (35.39 days) and longest on Rash (45.20 days). The fecundity (number of eggs laid per reproductive day) of S. oryzae reared on Hashemi (318.16 eggs) was about 2.5-fold higher than that on Rash (127.40 eggs). The highest intrinsic rate of increase (rm) was in S. oryzae reared on Hashemi (0.076 day−1), and the lowest was on Rash (0.043 day−1). The grain weight loss varied from 11.31% on Rash to 40.54% on Hashemi. Significant negative correlations were recorded between the starch, protein, and total phenolics content of tested grains and fecundity, rm, net reproductive rate (R0), and finite rate of increase (λ) of S. oryzae. Owing to slow development, poor fecundity, low grain weight loss, and low rm value of S. oryzae on cultivar Rash, it was more unsuitable diet than the other cultivars and lines for population growth of this weevil. Resistant rice cultivar(s) could be used in a manner consistent with other controlling methods for integrated management of S. oryzae.