Document Type

Article

Publication Date

4-1-2019

Abstract

The sugarcane aphid, Melanaphis sacchari (Zehntner) (Hemiptera: Aphididae), is an invasive pest of grain sorghum, Sorghum bicolor (L) Moench (Poaceae). Since its first outbreak in sorghum in 2013, severe infestations have spread throughout the southern USA, causing major economic losses. Whereas insecticide applications can mitigate some of the pest's impacts, a sustainable ecology-based management program is needed to reduce reliance on chemical control. Two greenhouse assays examined the influence of selected host plant characteristics on M. sacchari life table parameters. We studied the effects of silicon (rates equivalent to 0 and 3,360 kg silicon per ha) and nitrogen (rates equivalent to 0,110, and 224 kg nitrogen per ha) on M. sacchari growth and reproduction on a susceptible cultivar (SP 7868) in 2 phenological stages (5-leaf stage and boot stage). A second experiment examined the same silicon and nitrogen treatments on resistant (DKS 37-07) and susceptible (DKS 38-88) cultivars of grain sorghum. We calculated M. sacchari life table parameters including the intrinsic rate of increase, finite rate of increase, doubling time, and mean generation time for each treatment. Aphid population growth parameters were greater for plants in the 5-leaf stage than in the boot stage. In both experiments, nitrogen fertilization had a positive effect on M. sacchari fecundity, but effects of nitrogen on other parameters were less consistent. Silicon had a negative effect on life table parameters on sorghum plants in the boot stage, but effects were not consistent across treatments. Sorghum cultivar DKS 37-07 showed a high level of resistance, because no aphids survived to adulthood. These results suggest that resistant sorghum cultivars and nitrogen management could have a role in integrated pest management of M. sacchari.

Publication Source (Journal or Book title)

FLORIDA ENTOMOLOGIST

First Page

194

Last Page

201

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