RELATIVE SUSCEPTIBILITY OF HIGH-YIELDING RICE VARIETIES TO THE THRIPS, STENCHAETOTHRIPS-BIFORMIS (BAGNALL) (THYSANOPTERA, THRIPIDAE)

Of 18 high-yielding varieties screened, one variety was resistant to the thrips Stenchaetothrips biformis (Bagnall). Thrips-susceptible high-yielding varieties had high populations and high plant-damage ratings. Susceptible varieties were preferred for oviposition, adults lived longer and fecundity was higher than on resistant varieties. Population increase was nine times greater on susceptible than on resistant varieties. Inherent susceptibility of modern high-yielding varieties is believed to have contributed to increased severity of S. biformis in commercial rice fields. © 1990.