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定量评价农药对天敌的影响是IPM研究的重要内容之一,由于对天敌的捕食量缺乏有效的定量测量方法,农药对天敌摄食功能影响仍处于定性水平的研究,误差基数较大。本文采用一种定量的测定方法——荧光物示踪法,以稀土元素铕作为荧光示踪物质,定量地测定了食虫沟瘤蛛在重复接受噻嗪酮喷施后,其存活个体在药后13天内摄食量的变化趋势,且把药后食虫沟瘤蛛的死亡率加以考虑,计算药后整个试验食虫沟瘤蛛群体的摄食量变化。结果表明:任何浓度任何一次施药后2天左右食虫沟瘤蛛存活个体的捕食量均急剧下降;药物浓度较低时,第1次施药对食虫沟瘤蛛的影响最大;药物浓度较高时,食虫沟瘤蛛存活个体药后摄食量恢复周期较长。药后一段时间内整个食虫沟瘤蛛种群的摄食率相当低下,高浓度农药处理的食虫沟瘤蛛组3次施药后13天内的平均种群摄食率只有正常状况下的1/4左右(24.44%),推荐浓度及低于推荐浓度的食虫沟瘤蛛种群摄食率也仅为对照组的1/3左右(38.69%,36.52%)。因此在对水稻虫害防治时,应当尽可能地避免使用化学农药,充分发挥天敌对害虫数量的调控作用;当害虫数量超过经济阈值而必须施药时,也应当掌握农药用药剂量和次数的尺度,以利于食虫沟瘤蛛等稻田天敌的生理恢复和群落重建。
Quantitative evaluation of the effect of pesticides on natural enemies is one of the important aspects of IPM research. Due to the lack of an effective quantitative measurement of the predation of natural enemies, the impact of pesticides on the feeding function of the natural enemies is still at a qualitative level, with a large error base. In this paper, a quantitative determination method - fluorescent tracer method, the use of rare earth element europium as a fluorescent tracer substance, quantitative determination of the carnivorous Botryosphaeria crassipes spray repeated after receiving buprofezin, the survival of individuals in medicine After 13 days, the changing trend of food intake was taken into account, and the mortality of the post-drug insectivorous gonorrhea spider was taken into account, and the change of food intake of the entire experimental insecticidal group was calculated. The results showed that the predation amount of surviving individuals of Botryospora crassa decreased sharply at any concentration of 2 days after any one application. When the drug concentration was low, the first application had the greatest impact on Botryospar; Higher, the insects gully survival spores food consumption recovery period longer. After feeding for a period of time, the feeding rate of T. gondii population was very low. The average feeding rate of population within three days after application of pesticide with high concentration of pesticides was only about 1/4 in normal condition (24.44%). The feeding rates of the herbivorous nematode population were only about 1/3 (38.69%, 36.52%) of the control group at the recommended concentration and below the recommended concentration. Therefore, in the prevention and control of rice pests, chemical pesticides should be avoided as much as possible to give full play to the control effect of natural enemies on the number of pests. When the number of pests exceeds the economic threshold and pesticides must be applied, the dosage and number of pesticides should also be grasped, In order to facilitate the ecological restoration and community reconstruction of predatory paddy fields such as insects and worms.