Pataky J K, Michener P M, Freeman N D, Weinzierl R A, Teyker R H
Department of Crop Sciences, University of Illinois, Urbana 61801.
Del Monte Foods, Agricultural Research, Rochelle, IL 61018-9990.
Plant Dis. 2000 Oct;84(10):1104-1108. doi: 10.1094/PDIS.2000.84.10.1104.
Corn flea beetles, Chaetocnema pulicaria, vector Erwinia stewartii (synamorph Pantoea stewartii), which causes Stewart's bacterial wilt of corn (Zea mays). A seed treatment insecticide, imidacloprid, killed flea beetles and reduced the number of feeding wounds and Stewart's wilt symptoms per leaf in greenhouse studies. The objective of our research was to evaluate the ability of imidacloprid and thiamethoxam seed treatments to control Stewart's wilt on sweet corn hybrids under field conditions with naturally occurring populations of the corn flea beetle. Six field trials were planted at four locations in 1998. Eleven field trials were planted at nine locations in 1999. The treatment design was a factorial of sweet corn hybrids and seed treatments. Stewart's wilt incidence ranged from 0 to 54% in the 1998 trials. Incidence of Stewart's wilt in nontreated plots of the susceptible hybrid Jubilee ranged from 2% at the 8-leaf stage to 77% 1 week after mid-silk in the 1999 trials. Seed treatment insecticides reduced the incidence of Stewart's wilt by ≈50 to 85% relative to nontreated controls. The level of control was ≈75 to 85% in seven trials planted before 1 June 1999, when incidence of Stewart's wilt on nontreated Jubilee ranged from 4 to 71%. The level of control was ≈50 to 70% in the three trials planted after 1 July 1999, when incidence of Stewart's wilt on nontreated Jubilee ranged from 44 to 73%. Although comparisons varied, the level of control gained from seed treatment insecticides was similar to the next higher level of host resistance. Seed treatment insecticides appear to control Stewart's wilt during very early growth of corn plants, when foliar applications of insecticides are ineffective and the effectiveness of host resistance varies depending on the proximity of flea beetle feeding sites to the plant's growing point.
玉米跳甲（Chaetocnema pulicaria）是玉米斯图尔特氏菌（学名同物异名：斯图尔特泛菌Pantoea stewartii）的传播媒介，该细菌会引发玉米（Zea mays）的斯图尔特氏细菌性枯萎病。在温室研究中，种衣剂杀虫剂吡虫啉可杀死跳甲，并减少每片叶子上的取食伤口数量以及斯图尔特氏枯萎病症状。我们研究的目的是评估吡虫啉和噻虫嗪种衣剂在田间条件下，对于控制甜玉米杂交种上的斯图尔特氏枯萎病的能力，田间存在自然种群的玉米跳甲。1998年在4个地点进行了6次田间试验。1999年在9个地点进行了11次田间试验。处理设计为甜玉米杂交种和种衣剂的析因试验。在1998年的试验中，斯图尔特氏枯萎病发病率为0至54%。在1999年的试验中，易感杂交种“禧年”未处理地块的斯图尔特氏枯萎病发病率，在8叶期为2%，在吐丝中期后1周为77%。种衣剂杀虫剂使斯图尔特氏枯萎病的发病率相对于未处理对照降低了约50%至85%。在1999年6月1日前种植的7次试验中，防治水平约为75%至85%，此时未处理的“禧年”上斯图尔特氏枯萎病发病率为4%至71%。在1999年7月1日后种植的3次试验中，防治水平约为
