The sugarcane aphid [Melanaphis sacchari (Zehntner) (Hemiptera: Aphididae)] has been rapidly spreading in the United States and can cause devastating economic losses on sorghum [Sorghum bicolor (L.) Moench] when an effective management program is not utilized. Our objective was to determine if some of the most commonly used candidate bioenergy grasses can be alternative hosts of the sugarcane aphid. Host suitability was evaluated using aphid mortality and reproduction on each warm-season grass. An excised leaf bioassay was conducted for two continuous generations using eight bioenergy grasses and Johnsongrass [Sorghum halepense (L.) Pers.] as the control. Hosts that sustained multiple generations of the sugarcane aphid included Johnsongrass, energycane (Saccharum spp.), and giant miscanthus (Miscanthus x giganteus or Miscanthus sinensis x M. sacchariflorus Greef & Deuter ex Hodkinson & Renvoize). Poor hosts included the napiergrass [Cenchrus purpureus (Schumach.) Morrone] cultivar Merkeron, giant reed (Arundo donax L.), and switchgrass (Panicum virgatum L.) cultivar GA-001. Erianthus arundinaceus (Retz.) Jeswiet was a good host for first generation sugarcane aphids but a poor host for second generation aphids. Thus, the findings from the current study suggest that, if widespread planting of these bioenergy grasses were to occur, the plantings of napiergrass, giant reed, and switchgrass may prevent the further increase of the aphid population. Whereas the planting of the energycane and giant miscanthus may exacerbate sugarcane aphid damage on sorghum.
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