Effects of host grains on the rice weevil Sitophilus oryzae (L.) Thakkar Bhumi, Parikh Pragna* Division of Entomology, Department of Zoology, Faculty of Science, The Maharaja Sayajirao University of Baroda, Vadodara, 390002 *Corresponding author Email: php59@yahoo.co.in
Online published on 5 February, 2019. Abstract The present study observed the effect of host grains on oviposition, emergence, body length, longevity and sex ratio of adults of Sitophilus oryzae (L.), an important storage pest of cereals. Grains of maize, rice, pearl millet and chickpea were evaluated in primary culture under laboratory conditions. The results revealed variations in the developmental period (from egg to adult)-the least was on maize (32.5 days) and maximum with pearl millet (43 days). The body length of the male and female also varied-females were longer than males in all the evaluated grains. Maximum fecundity and longevity were found in maize with 453 adults in the lifespan of 184 days. The female: male ratio was not affected in a significant manner with cereals (maize-2.36: 1, rice-2.35: 1 and millet-2.21: 1), but decreased to 1.98: 1 with chickpea. A linear relationship with a significant correlation between grain loss and adult emergence was observed. These results reveal that S. oryzae exhibits host preference as its fecundity and longevity are significantly affected with various host grains. Top Keywords Sitophilus oryzae, mass culture, maize, rice, pearl millet, chick pea, oviposition, developmental period, emergence, fecundity, longevity, adult length. Top |