Intraspecific competition among larvae of the indianmeal moth suggested a scramble-like competition. The number of female moth progeny was inversely proportional to the female moth introduced. When the moth occurred together with the rice weevil, significantly more female progenies were produced, suggesting that severity of the larval competition be reduced by the rice weevil. The impacts of the rice weevil on the moth population were discussed briefly in the context of interspecific competition between the adult rice weevil and young moth larvae.