Delta Research and Extension Center, Mississippi State University, Stoneville, MS.
Department of Biochemistry, Molecular Biology, Entomology, and Plant Pathology, Mississippi State University, Mississippi State, MS.
J Econ Entomol. 2020 Oct 16;113(5):2235-2240. doi: 10.1093/jee/toaa158.
An experiment was conducted at the Delta Research and Extension Center in Stoneville, MS during 2017 and 2018 to determine whether removal of the flood is an economical method of control for rice water weevil, Lissorhoptrus oryzophilus Kuschel. This experiment compared a continuous flood production system to draining a rice field completely and reestablishing a flood for the remainder of the growing season. In addition, two insecticide seed treatments, thiamethoxam and chlorantraniliprole, were compared with an untreated control within each system. Rice water weevil densities were measured prior to draining at 3 wk after flood and again after the flood was reestablished in drained plots. Rice water weevil densities were greater in 2017 than 2018. Chlorantraniliprole at the predrainage and postdrainage sample timing reduced larval numbers compared with the untreated control. The plots where water was removed until soil cracking then re-flooded had significantly lower weevil populations than plots that were continuously flooded during 2018 only. Draining of plots resulted in lower yields in 2018, but not in 2017. Additionally, both of the insecticide seed treatments resulted in greater yields and economic returns than the untreated control. Draining of flooded rice when rice water weevil larvae were present did not provide a consistent benefit, and may result in yield and economic penalties. Insecticide seed treatments consistently provided greater yield benefits in flooded rice. Based on these results, draining of flooded rice is not recommended to manage rice water weevil and insecticide seed treatments should be used to minimize economic losses.
2017 年和 2018 年，在密西西比州斯通维尔的三角洲研究与推广中心进行了一项实验，以确定是否排干洪水是控制稻水象甲（Lissorhoptrus oryzophilus Kuschel）的经济方法。该实验比较了连续淹水生产系统与完全排干稻田并在生长季剩余时间重新建立洪水的方法。此外，在每个系统中，将两种杀虫剂种子处理（噻虫嗪和氯虫苯甲酰胺）与未处理的对照进行了比较。在排干前、淹水后 3 周和排干后重新建立洪水时，测量了稻水象甲的密度。2017 年的稻水象甲密度高于 2018 年。在预排和后排样本时间，氯虫苯甲酰胺处理与未处理对照相比，降低了幼虫数量。在土壤干裂后放水然后再重新淹没的地块中，2018 年的稻水象甲种群明显低于连续淹没的地块。排干地块导致 2018 年的产量降低，但在 2017 年没有降低。此外，两种杀虫剂种子处理的产量和经济效益均高于未处理对照。在稻水象甲幼虫存在的情况下排干水淹稻田并没有带来持续的好处，反而可能导致产量和经济损失。杀虫剂种子处理在水淹稻田中始终提供更大的产量收益。基于这些结果，不建议排干水淹稻田来防治稻水象甲，应使用杀虫剂种子处理来最大程度地减少经济损失。
