Antifeedant of Barnyard Grass Against the Brown Planthopper , u Niloparvata lugens ( STAL ) ( Homoptera : Delphacidae )

Barnyard grass (var. onyzicela) showed no apparent damage in paddy fields where hopperburn occurred by a large number of NL lugens. The causes of barnyard grass resistance to this inscct and thc insect-host interrelations of threc species of planthoppers (N. Iugens, L. striatellus and S. farctfera) between rice plant and barnyard grass were studicd. Nymphs of IV. Iugens could not grow by feeding barnyard grass without regard to its leafstage and died within a few days, whereas those grew well by feeding riee plant. On the contrary, nymphs of the other two specics of p]anthoppers grew up normally to the adult stage even en barnyard grass as well as on rice plant. Extract of bamyard grass showcd an antifocdant efllect