Abstract The sugarcane aphid, Melanaphis sacchari Zehntner, is an economically damaging pest of sorghum, Sorghum bicolor (L.), across the southern United States. Field experiments investigated impacts of sorghum cultivar, nitrogen fertilization, and insecticides on M. sacchari infestations and sorghum yields in Louisiana and South Carolina in 2017 and 2018. In South Carolina, M. sacchari densities in unprotected plots peaked on 30–31 July of both years before declining by early- to mid-August. In Louisiana, infestations peaked on 26 and 12 July for 2017 and 2018, respectively, and declined by mid-August. Nitrogen fertilization influenced M. sacchari densities in Louisiana in 2018 with the highest-level infestations recorded from plots that received high N rates. Densities of M. sacchari on susceptible sorghum cultivar, DKS 38-88, were 1.5- to 2.3-fold greater than on DKS 37-07 in both years in Louisiana and in 2018 in South Carolina. Nitrogen fertilization was associated with improved sorghum yields in Louisiana experiments. Sorghum yields across experiments were 2- to 4-fold greater in plots protected with multiple insecticide applications than in unprotected plots. Yield from plots with insecticides sprayed once at currently used action thresholds differed from unprotected plots only in the 2018 Louisiana experiment. Results from these experiments indicate insecticidal protection of susceptible sorghum cultivars remains critical throughout much of the southern United States. Further research is needed to develop integrated management programs that incorporate fertilization manipulation, cultivar resistance, and insecticidal control.

中文翻译：

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高粱品种、氮肥和杀虫剂对美国南部甘蔗蚜虫（半翅目：蚜虫科）侵染的影响

摘要 甘蔗蚜虫 Melanaphis sacchari Zehntner 是美国南部高粱 Sorghum bicolor (L.) 的一种经济破坏性害虫。田间试验调查了 2017 年和 2018 年路易斯安那州和南卡罗来纳州高粱品种、施氮肥和杀虫剂对糖分枝杆菌侵染和高粱产量的影响。在南卡罗来纳州，无保护地块中的糖精分枝杆菌密度在 7 月 30 日至 31 日达到峰值8 月初至中旬下降。在路易斯安那州，虫害分别在 2017 年和 2018 年的 7 月 26 日和 12 日达到高峰，到 8 月中旬下降。施氮肥影响了 2018 年路易斯安那州的 M. sacchari 密度，从接受高 N 率的地块记录的最高水平的侵染。易感高粱品种 DKS 38-88 上的 M. sacchari 密度为 1.5 至 2。在路易斯安那州和 2018 年在南卡罗来纳州，这两年比 DKS 37-07 高出 3 倍。在路易斯安那州的实验中，施氮肥与提高高粱产量有关。在使用多种杀虫剂保护的地块中，实验中的高粱产量比未受保护的地块高 2 到 4 倍。仅在 2018 年路易斯安那州实验中，以当前使用的行动阈值喷洒一次杀虫剂的地块的产量与未受保护的地块不同。这些实验的结果表明，在美国南部的大部分地区，易感高粱品种的杀虫保护仍然至关重要。需要进一步研究以制定综合管理计划，包括施肥操作、品种抗性和杀虫控制。