Souza M F, Davis J A
Department of Entomology, Louisiana State University Agricultural Center, 404 Life Sciences, Baton Rouge, LA.
Environ Entomol. 2020 Jun 13;49(3):683-691. doi: 10.1093/ee/nvaa036.
Worldwide, Melanaphis sacchari Zehntner is reported on several plants in the family Poaceae, including important crops. In the United States, M. sacchari has been present primarily on sugarcane (Saccharum officinarum L.), but recently sorghum (Sorghum bicolor (L.) Moench) has become a main host. It is not clear how M. sacchari exploits sorghum or other plant species present in the Louisiana agro-ecoscape, but there is potential for these plants to be bridging hosts. Thus, this study determined the feeding behavior of M. sacchari on sorghum, rice, Oryza sativa (L.), sweetpotato, Ipomea batatas (L.), maize, Zea mays (L.), Johnsongrass, S. halepense (L.), and wheat Triticum aestivum (L.) using electrical penetration graphs. Melanaphis sacchari established sustained feeding on sorghum, Johnsongrass, wheat, and rice, only a negligent percentage on maize and no aphid fed on sweetpotato. Differences in Electrical Penetration Graph parameters among the plants in nonpenetrating total time and the lower number of probes, time to penetration initiation, proportion of individuals probing, number of probes shorter than 30 s, number of probes longer than 30 s but shorter than 3 min, pathway phase duration, and number of cell punctures during pathway phase, suggest epidermis and mesophyll factors affecting aphid feeding behavior. While the lack of differences in number of feeding occurrences, total time feeding, and number of sustained feeding occurrences shows that M. sacchari is able to feed on those plants, sieve element factors such as resistance or low nutritional quality prevent the growth of this population in field.
在全球范围内，甘蔗蚜（Melanaphis sacchari Zehntner）被报道寄生在禾本科的多种植物上，包括重要作物。在美国，甘蔗蚜主要寄生在甘蔗（Saccharum officinarum L.）上，但最近高粱（Sorghum bicolor (L.) Moench）已成为主要寄主。目前尚不清楚甘蔗蚜如何利用高粱或路易斯安那州农业生态系统中的其他植物物种，但这些植物有可能是桥梁寄主。因此，本研究使用刺探电位图谱技术测定了甘蔗蚜在高粱、水稻（Oryza sativa (L.)）、甘薯（Ipomea batatas (L.)）、玉米（Zea mays (L.)）、约翰逊草（S. halepense (L.)）和小麦（Triticum aestivum (L.)）上的取食行为。甘蔗蚜能在高粱、约翰逊草、小麦和水稻上持续取食，在玉米上只有极少比例的蚜虫取食，而没有蚜虫取食甘薯。不同植物在非刺探总时间、刺探次数较少、开始刺探时间、刺探个体比例、短于30秒的刺探次数、长于30秒但短于3分钟的刺探次数、路径阶段持续时间以及路径阶段的细胞穿刺次数等刺探电位图谱参数上存在差异，这表明表皮和叶肉因素会影响蚜虫的取食行为。虽然取食发生次数、总取食时间和持续取食发生次数没有差异，表明甘蔗蚜能够在这些植物上取食，但筛管分子因素，如抗性或低营养质量，会阻止该种群在田间生长。
