Reactions of resistant and Susceptible rice varieties to infestation by the yellow borer, Tryporyza incertulas (Walker) (Lepidoptera; Pyralidae)

Abstract

Six rice varieties previously recorded as being moderately to highly resistant to the yellow borer, Tryporyza incertulas (Walker), together with a susceptible check, were utilized in studies to determine the development of’dead hearts’, the effect of host plants on survival and development of larvae, and the effect of infestation on tillering ability. Symptoms of damage appeared earlier in susceptible than in resistant varieties and the age of the plants at the time of infestation appeared to significantly influence their susceptibility to the yellow borer. The larvae reared on resistant varieties had lower survival and weighed less than those reared on the susceptible variety. Both resistant and susceptible varieties produced additional tillers under heavy infestation. The tillering ability was independent of the degree of susceptibility of a variety.