短额负蝗为害烟草的经济损失与防治指标研究

采用大田笼罩接虫法研究短额负蝗为害烟草经济损失结果表明，烟株上虫量越大，中上等烟叶下降比率和经济损失越大。单株虫量１、２、４头造成的中上等烟叶下降比例分别是６．０７％、２６．２９％、３９．７２％，经济损失率分别为１４．１７％、３１．８５％、４８．０１％；底叶、下二棚叶、腰叶、上二棚叶、顶叶受害指数分别是１．３９、１３．５４、１８．０６、２５．００、１４．８２。计算出了经济阈值，确定短额负蝗防治指标为６头／１００株

Economic Loss and Action Threshold of Atractomorpha sinensis in Tobacco.

The economic loss of tobacco damaged by Atractomorpha sinensis Bolivar with method of inoculation pest test in cage condition was studied in Fuxian of Shaanxi Province in 1994. The results showed that the percentage of good grade leaves of tobacco plants decreased significantly. The damaged indexes were 1.39, 13.54, 18.06, 25.00 and 14.82 on the lst 3rd, 4th-7th, 8th-10th, 11th-14th and 15th-19th leaves from the bottom up to the terminal of tobacco plants, respectively. The percentage decreasing in rate of middle and superior leaves were 6.07%, 26.29% and 39.72% and were 14.17% , 31.85% and 48.01% in economic loss due to the damage of 1, 2 and 4 pests in one plant, respectively. The economic threshold was proposed and the action threshold was six pests per 100 plants in the tobacco field.