草原蝗虫防治指标的研究

作者测定了4种蝗虫从孵化至成虫期的食量,把草原蝗虫划分为以红翅皱膝蝗、邱氏异爪蝗和狭翅雏蝗为代表的大、中、小三种食量类型,混合种群虫口密度(x)与其对牧草取食量(y)的模型为y=16.4732x。通过野外混合种群不同密度下对牧草产量损失的测定,回归式为(ŷ)=-20.8070+14.4143x±15.56(r=0.9993,F>F_0.01),两种方法计算的防治指标分别为21.7、26.2头/m²,其经济允许损失均为8.8%。大、中、小三种食料类型的防治指标分别为5.2、17.6和32.3头/m²。

STUDY ON THE ACTION THRESHOLD OF THE GRASSLAND GRASSHOPPERS

Based on the individual grass consumption test of four grasshopper species from hatching to adult stage, the feeding types of grassland grasshoppers were classified as more-, medium-and less-consumption represented by Angaraeris rhodopa, Euchorthip-pus cheui and Chorthippus dubius respectively. The proportion of compound population density per square meter to grass consumption (kg) was determined as 1:16.4732, and the regression equation reflecting the relationship between that density (x) and yield loss rate of grass was derived as ŷ=-20.8070+14.4143x±15.56(r=0.9993, F>F_0.01) According to the two results mentioned above, the action thresholds were obtained as 21.7 and 26.2 grasshopper no./square meter respectively, and both the economic tolerant yield loss rates were 8.8%. The action thresholds of single species belonged to the three consumption types were 5.2 (more consumption),17.6 (medium consumption) and 32.3 (less consumption) grasshopper no./square meter.