Food Preference of Pecky Rice Bugs Is Influenced by Experience

Abstract

This study investigated whether prior experience influences the plant food preference of Trigonotylus caelestialium and Stenotus rubrovittatus which cause pecky rice grain, by using rice plants and 2 poaceous weeds. In a choice experiment between Digitaria ciliaris and the rice plants, both T. caelestialium and S. rubrovittatus adults that were reared on D. ciliaris plants showed significant initial preference for D. ciliaris over rice. In a choice experiment between Echinochloa crus-galli var. aristata and rice plants, T. caelestialium adults reared on E. crus-galli var. aristata strongly preferred E. crus-galli var. aristata over rice throughout the experiment. However, at and after 24 h, T. caelestialium adults reared on rice showed no food preference, although T. caelestialium initially preferred E. crus-galli var. aristata. In contrast, S. rubrovittatus adults reared on rice showed no preference between E. crus-galli var. aristata and rice. However, S. rubrovittatus reared on E. crus-galli var. aristata initially preferred E. crus-galli var. aristata to rice, with this preference waning with time. The same results were obtained for both sexes. Although the effect of experience differed with food source and the species of mirid bug, prior experience initially had a noticeable effect, which disappeared with time (1 d).