Mahmoud M A B, Sharp R E, Oliver M J, Finke D L, Bohn M, Ellersieck M R, Hibbard B E
Division of Plant Sciences and Interdisciplinary Plant Group, University of Missouri, Columbia, MO.
Department of Entomology, Faculty of Science, South Valley University, Qena, Egypt.
J Econ Entomol. 2018 Feb 9;111(1):193-208. doi: 10.1093/jee/tox309.
Anecdotal data in the past have suggested that the effect of the western corn rootworm, Diabrotica virgifera virgifera LeConte (Coleoptera: Chrysomelidae), on maize yield is greater under drought and the effect of drought is greater under rootworm infestations, but no field experiments have controlled both moisture and rootworm levels. Field studies were conducted in 2012, 2013, and 2014 with treatments in a factorial arrangement of western corn rootworm infestation levels, and maize hybrids (with and without tolerance to drought and rootworm feeding). The experiment was repeated under well-watered and drought conditions in adjacent plots. Leaf water potential and stomatal conductance data suggested significant plant stress was achieved in the drought plots toward the end of the season each year and maize hybrids only played a minor role. In particular, in 2012 and 2013 yield was dramatically lower for the drought experiment than for the well-watered experiment. However, the impacts of rootworm infestation level and maize hybrids on water potential, stomatal conductance, and yield were variable across years and between experiments. In fact, the only year that the main effect of rootworm infestation levels significantly impacted yield was in 2014, when an extremely high infestation level was added and this was only for the well-watered portion of the experiment. Overall, rootworm infestation level played a relatively minor role in maize productivity and it did not appear that soil moisture level influenced that to a large degree.
过去的轶事数据表明，西部玉米根萤叶甲（Diabrotica virgifera virgifera LeConte，鞘翅目：叶甲科）对玉米产量的影响在干旱条件下更大，而干旱的影响在根萤叶甲侵害情况下更大，但尚无田间试验同时控制湿度和根萤叶甲水平。2012年、2013年和2014年进行了田间研究，处理采用西部玉米根萤叶甲侵害水平与玉米杂交种（有和没有耐旱性及耐根萤叶甲取食性）的析因排列。该试验在相邻地块的充分灌溉和干旱条件下重复进行。叶片水势和气孔导度数据表明，每年季末干旱地块出现了显著的植物胁迫，玉米杂交种仅起次要作用。特别是，2012年和2013年干旱试验的产量比充分灌溉试验的产量大幅降低。然而，根萤叶甲侵害水平和玉米杂交种对水势、气孔导度和产量的影响在不同年份和不同试验之间存在差异。事实上，根萤叶甲侵害水平的主要效应显著影响产量的唯一一年是2014年，当时增加了极高的侵害水平，且这仅针对试验的充分灌溉部分。总体而言，根萤叶甲侵害水平对玉米生产力的作用相对较小，而且土壤湿度水平似乎并未在很大程度上对其产生影响。
