贵州稻水象甲危害损失和防治指标研究

Studies on the harm loss and economic threshold of Lissorhoptrus oryzophilus Kuschel in Guizhou

【目的】为了摸清贵州稻水象甲Lissorhoptrus oryzophilus Kuschel危害与水稻产量损失的关系,明确贵州稻水象甲的防治指标。【方法】采用田间笼罩接虫法系统的研究了不同密度的稻水象甲成虫与水稻被害叶率、幼虫密度、水稻分蘖数、穗数、穗粒数、千粒重、产量损失等的关系。【结果】稻水象甲成虫密度与水稻被害叶率和幼虫密度呈正相关关系;稻水象甲的危害明显减少水稻分蘖数和穗数,但对穗粒数和千粒重的影响不大。建立了产量损失率与被害叶率、成虫密度、幼虫密度的回归方程,计算获得了插秧后的第5天、第10天、第15天、第20天的叶片被害率的防治指标为59.65%、52.97%、50.96%、48.52%,成虫的防治指标为20头/m^2(1头/丛),幼虫的防治指标为130头/m^2(6.5头/丛)。【结论】该结果对贵州省稻水象甲的预测预报及防治具有重要的指导意义。

[Objectives] In order to control the Lissorhoptrus oryzophilus, efficaciously. [Methods] The tests on the damage and economic threshold of rice, was carried out by envelop modifying the density of L. oryzophilus. [Results] Infected rate of rice [eaves, larval density, tillering number and single yield difference was significant, spike number, grains per spike and 1000-grain weight had not significant difference, regression equations among the loss rate of yield and infected rate of leaves were established, after rice transplanting 5 days, 10 days, 15 days, 20 days, the economic threshold for infected rate of rice leaves were 59.65%, 52.97%, 50.96%, 48.52%. Regression equations among the loss rate of yield and the adult density and among the loss rate of yield and the larval density were established, the economic threshold for the adult were 20 adult per square meter, the economic threshold for the larval were 130 larval per square meter. [Conclusion] This results has important guiding meaning to prediction and prevention of Guizhou.