Medrano Enrique Gino, Esquivel Jesus F, Nichols Robert L, Bell Alois A
Cotton Pathology Research Unit, USDA-ARS, 2765 F&B Rd., College Station, TX 77845, USA.
J Econ Entomol. 2009 Feb;102(1):36-42. doi: 10.1603/029.102.0106.
The southern green stink bug, Nezara viridula (L.), is a significant pest of cotton, Gossypium hirsutum L., and is becoming an increasing challenge due to the decrease in use of broad-spectrum insecticides on the crop. The southern green stink bug can vector an opportunistic Pantoea agglomerans strain (designated Sc 1-R) into cotton bolls, resulting in infection. The appearance of stink bug damage varies, and pest managers cannot readily identify its source. This research reports a systematic depiction of green, immature boll responses at various stages of maturity (1, 2, and 3 wk post-anthesis [WPA]) to stink bug injury and to infection by the vectored cotton pathogen by demonstrating the progression of effects 1, 2, and 3 wk after exposure (WAE). When laboratory-reared adult southern green stink bug not harboring Sc 1-R deposited bacteria into greenhouse-grown bolls at 1, 2, or 3 WPA during feeding/probing, bacteria reached concentrations of 10(9), 10(9), and 10(3) colony-forming units (CFUs)/g tissue, respectively, at 3 WAE, yet caused minimal seed and lint damage regardless of the age of the bolls that were penetrated. Bolls at a maturity of 1 or 2 WPA showed similar susceptibility when exposed to stink bugs that vectored Sc 1-R. After a week of infection, seeds were salmon-pink with normal white lint and up to 10(4) CFUs/g tissue when Sc 1-R was detected. Necrosis of the entire inoculated locule(s) with a maximum Sc 1-R concentration detected at 10(8) CFUs/g tissue occurred in samples harvested 2 or 3 WAE. Conversely, seed and lint deterioration due to the transmitted opportunist into bolls exposed 3 WPA was confined to the puncture site. In summary, after a week of development, bolls were tolerant to southern green stink bug feeding/ probing damage and to nonpathogenic bacteria, but they were severely damaged when the opportunistic pathogen Sc 1-R was transmitted. At 3 WPA, the fruit was immune to the spread of the pathogen with infections confined to the puncture site.
南方绿蝽（Nezara viridula (L.)）是棉花（Gossypium hirsutum L.）的一种重要害虫，由于作物上广谱杀虫剂使用量的减少，其带来的挑战日益增加。南方绿蝽可将一种机会性成团泛菌菌株（命名为Sc 1-R）传播到棉铃中，导致感染。蝽象危害的外观各不相同，害虫防治人员难以轻易确定其来源。本研究通过展示暴露后1、2和3周（WAE）的影响进展，系统描述了绿色未成熟棉铃在不同成熟阶段（开花后1、2和3周[WPA]）对蝽象伤害以及对传播的棉花病原体感染的反应。当实验室饲养的未携带Sc 1-R的成年南方绿蝽在取食/刺探过程中将细菌沉积到温室种植的棉铃中时，在1、2或3 WPA时，细菌在暴露后3周分别达到10⁹、10⁹和10³菌落形成单位（CFU）/克组织的浓度，但无论被穿透棉铃的年龄如何，对种子和棉绒造成的损害都很小。当暴露于携带Sc 1-R的蝽象时，1或2 WPA成熟的棉铃表现出相似的易感性。感染一周后，当检测到Sc 1-R时，种子呈鲑鱼粉红色，棉绒正常为白色，组织中每克高达10⁴ CFU。在暴露后2或3周收获的样本中，整个接种室出现坏死，检测到的Sc 1-R最高浓度为10⁸ CFU/克组织。相反，由于传播的机会性病原体进入3 WPA暴露的棉铃，种子和棉绒的变质仅限于穿刺部位。总之，发育一周后，棉铃对南方绿蝽的取食/刺探伤害以及对非致病性细菌具有耐受性，但当传播机会性病原体Sc 1-R时，它们会受到严重损害。在3 WPA时，果实对病原体的传播具有免疫力，感染仅限于穿刺部位。
