Yellow Pan Water Trap for Sampling the Small Brown Planthopper, Laodelphax striatellus (FALLEN), a Vector of the Rice Stripe Virus
1968 年 3 巻 1 号 p. 37-48
詳細
1968 年 3 巻 1 号 p. 37-48
For sampling the small brown planthopper, Laodelphax striatellus (FALLEN), a vector of the rice stripe virus, pan water traps of various colors were tested.Yellow pans which were set at the crop level attracted three times as many planthoppers as green or white pans, and black pans attracted about one tenth of those by yellow pans. Catching efficiency per area of pan decreased with increase of size of pan and pan of 60 cm in diameter seemed to be highest in efficiency and also convenient for handling. Yellow pans set at 1.5m height above the ground caught one tenth to one fourth as few planthoppers as pans set at the crop level.Sampling by yellow pan water trap was compared with those by insect net sweeping and counting by eyes. At the beginning of the immigration season of the first generation or soon after the transplantation of rice plant, yellow pans showed higher efficiency than the other methods. Catching curves by yellow pan preceded those by counting. It was considered that yellow pan sampled planthoppers which were actively flying at the crop level and counting estimated the density of planthoppers settled down on rice plants. Level of catching by a yellow pan corresponded to that of 5 hills by counting as a general trend.Sampling by sweeping much depended on the growth stage of rice plant, not necessarily with the density of planthopper. Catching by yellow pans showed the diurnal periodicity, bimodal curve of high catching from 5.00 to 11.00 in the morning and 15.00 to 19.00 in the evening. In 1963 and 1965 high catches were obtained in the season of the first generation but much less catches in 1964.Catch curves were composed of several minor peaks, synchronized among several plots. Coincidence of attractive stage of rice plant, 10 days to 2 weeks after transplantation, with the peak of immigration of planthopper induced high catches, consequently the severe infection of the rice stripe virus.
