Detecting change in a sorghum field infested by sugarcane aphid

Authors: BACKOULOU, GEORGES - Oklahoma State University; Elliott, Norman - Norm; GILES, KRISTOPHER - Oklahoma State University; BREWER, MICHAEL - Texas A&M University; STARKE, MIKE - Texas A&M University

Submitted to: Southwestern Entomologist
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 10/15/2018
Publication Date: 12/1/2018
Citation: Backlolou, G.F., Elliott, N.C., Giles, K.L., Brewer, M.J., Starke, M. 2018. Detecting change in a sorghum field infested by sugarcane aphid. Southwestern Entomologist. 43(4):823-832. https://doi.org/10.3958/059.043.0401.
DOI: https://doi.org/10.3958/059.043.0401

Interpretive Summary: The sugarcane aphid is a destructive pest of sorghum in the United States. Sugarcane aphid outbreaks have been reported in commercial sorghum fields in Mississippi, Louisiana, Texas, Oklahoma, and Kansas, and in several eastern U.S. states. This study explores the use of airborne multispectral remote sensing for assessing change over time in sugarcane aphid infestations in grain sorghum fields. The results indicated that it is possible to detect and assess change in sorghum fields infested by sugarcane aphids. The analysis demonstrated that a 65% increase in the area within a field severely infested by sugarcane aphids in one week's time. The study demonstrates how rapidly a sugarcane aphid infestation spreads within a field and how the spatial spread of the infestation proceeds. The significance lies in helping establish a foundation for using remote sensing to detect infestations for purposes of making management decisions regarding insecticidal application to suppress the infestation.

Technical Abstract: The sugarcane aphid (SCA), Melanaphis sacchari (Zehntner), is a destructive pest of sorghum, Sorghum bicolor Moench, in the United States. Outbreaks of SCA have been reported in commercial sorghum fields in Mississippi, Louisiana, Texas, Oklahoma, and Kansas. Infestations of SCA in sorghum fields are initiated when winged aphids land on sorghum plants in the field and begin to reproduce. Infestations in a field are not uniform and can increase in size and intensity very rapidly. This study explores the use of airborne multispectral remote sensing for assessing change over time in sugarcane aphid, Melanaphis sacchari (Zehntner), infestations in grain sorghum fields. Differencing of bi-temporal normalized differenced vegetation index images followed by analysis of change depicted numerically in the differenced NDVI image was effective for assessing the extent of temporal change in a sugarcane aphid infestation in a commercial grain sorghum field. Classification of NDVI imagery from two dates into land cover categories including one for sorghum infested with sugarcane aphid, followed by comparison of change in area and distribution of categories was also a useful method for assessing temporal change in sugarcane aphid infestations in sorghum. The results indicated that it is possible to detect and assess change in sorghum fields infested by sugarcane aphids. The analysis demonstrated that a 65% increase in the area within a field severely infested by sugarcane aphids in one week's time.