水稻-褐飞虱-拟水狼蛛食物链的定量研究

应用荧光物质稀土元素铕示踪法对水稻褐飞虱拟水狼蛛食物链进行了定量分析研究。所施荧光物质的三种浓度20 mg/L、50 mg/L和100 mg/L 均为有效浓度，对水稻生长无可见的影响，孕穗期、抽穗期、乳熟期和黄熟期四个生育期水稻、褐飞虱和拟水狼蛛的荧光物含量均随所施荧光物质浓度的增高而增高。褐飞虱对不同生育期水稻的取食量依次为抽穗期>孕穗期>乳熟期>黄熟期，分别为每克褐飞虱生物量在24 h内摄食水稻17.5910 g, 17.4510 g, 13.8290 g和8.7070 g。拟水狼蛛对褐飞虱的捕食量为乳熟期>孕穗期>抽穗期>黄熟期，分别为每克拟水狼蛛生物量24 h捕食褐飞虱3.6380 g, 3.0830 g, 3.0770和2.8000 g。根据田间调查数据换算为每头拟水狼蛛捕食褐飞虱在孕穗期、抽穗期、乳熟期和黄熟期分别为11头、11头、13头和10头。

A quantitative study on the food chain of late-season rice-Nilaparvata lugens Stal-Pirata subpiraticus (Bosenberg et Strand)

Using fluorescent element Eu⁺³ tracing method, the food chain of late season rice Nilaparvata lugens Stal Pirata subpiraticus (Bosenberg et Strand) was studied quantitatively. Three concentrations of Eu₂O₃, 20 mg/L, 50 mg/L and 100 mg/L, with no obvious negative effect on growth of rice plant, were applied in substrate of potted rice, respectively. During rice booting, tasseling, milking and maturing stages, the content of u⁺³ in rice, N. lugens and P. subpiraticus markedly increased with the rise of concentrations of Eu₂O₃ applied. Ingestion of rice by N. lugens during the tasseling stage was the highest (17.5910 g/g biomass day), while the lowest (8.7070 g/g biomass day) occurred during the maturing stage. Between them, ingestion of rice by the planthopper was higher during the booting stage (17.4510 g/g biomass day) than during the milking stage (13.8290 g/g biomass day). Predation of N. lugens by P. subpiraticus was almost the same, about 3.6380 g/g biomass per day during the milking stage, higher than during the booting stage (3.0830 g/g biomass day) and the tasseling stage (3.0770 g/g biomass day) while the smallest predation (28000 g/g biomass day) occurred during the maturing stage. Based on the investigation in rice fields, the number of N. lugens consumed by P. subpiraticus during these four growth stages of the rice plant was estimated to be 11, 11, 13 and 10 respectively.