The relative resistance of rice varieties to Maliarpha separatella was studied during 1981 and 1982 long rain seasons. The observations covered the laying of egg masses, tiller infestation, incidence of “whiteheads” and, in some cases, the grain yield.
The results indicated that the varieties BG 34™8 and BG 90™2 received the highest egg masses per plot which apparently caused “whiteheads”. The remaining 10 varieties only indicated moderate response. The 1982 long rain season under no control and carbofuran 5G application regimes showed reduced tiller infestation only in BG 90™2 and Basmati 217. The five tested varieties did not show any marked difference in tiller infestation under the two regimes. Hence, BG 90™2 and Basmati 217 showed some susceptibility of M. separatella, while the rest of the varieties remained moderately resistant.
Moth population varied according to the growth stages of the rice crop in the field, with the peak occurring during the booting to maturation stages.
