Location: Crop Genetics and Breeding ResearchTitle: A sugarcane aphid (Hemiptera: Aphididae) 'Super-clone' remains on U.S. sorghum and johnsongrass ands feeds on giant miscanthus
Submitted to: Journal of Entomological Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 3/28/2020
Publication Date: 2/12/2021
Citation: Harris-Shultz, K.R., Ni, X. 2021. A sugarcane aphid (Hemiptera: Aphididae) 'Super-clone' remains on U.S. sorghum and johnsongrass ands feeds on giant miscanthus. Journal of Entomological Science. 56(1):43-52. https://doi.org/10.18474/0749-8004-56.1.43.
Interpretive Summary: The sugarcane aphid has been a perennial pest on sorghum in the U.S. since 2013. Sugarcanes aphids, although small in size, can build to tremendous numbers with 10,000 aphids being recorded on a single sorghum plant. Plant damage ranges from leaf pigmentation to plant death. Scientists from the USDA-ARS in Tifton, GA and colleagues discovered that the sugarcane aphids that were spreading in the U.S. on sorghum from 2013-2017 were predominantly one super-clone (one genotype). In this study sugarcane aphids were collected from seven states and one territory from Columbus grass (Sorghum almum Parodi), Johnsongrass, sorghum, sugarcane and giant miscanthus from 2013-2019 and were genotyped using genetic markers. They found that the super-clone was still pervasive in the U.S. in 2018 and that it is using giant miscanthus as an alternate host.
Technical Abstract: Since 2013, the sugarcane aphid (Melanaphis sacchari Zehntner) is a perennial pest to U.S. sorghum (Sorghum bicolor [L.] Moench) causing a 50-100% yield decline in susceptible hybrids. Previous studies have found that a single clonal genotype predominates in samples collected from sugarcane (Saccharum spp.), sorghum, and Johnsongrass (Sorghum halepense [L.] Persoon), from 2013-2017 in the continental U.S. We sought to monitor sugarcane aphid samples collected in 2018 and to determine the multilocus lineage (MLL) of samples collected from a new host giant miscanthus in 2018-2019 (Miscanthus sinensis x M. sacchariflorus Greef & Deuter ex Hodkinson & Renvoize). Thirty-one samples collected from five states and one territory from Columbus grass (Sorghum almum Parodi), Johnsongrass, sorghum, and giant miscanthus in 2018 were genotyped using nine simple sequence repeat (SSR) markers and 29 samples had identical alleles to the MLL-F superclone. All samples (N= 7) collected from giant miscanthus in 2018-2019 also had identical alleles to the predominant genotype.