(Note: The following article is from K-State’s “Kansas Insect Newsletter,” August 25, 2016: http://entomology.k-state.edu/doc/extension-newsletters/2016/KSInsectNewsletter25.pdf – Steve Watson, Agronomy eUpdate Editor)
Double cropped sorghum may still have some fall armyworm “ragworm” feeding during the whorl stage. In addition, there will probably be at least one more generation of headworms. Thus, later-planted sorghum needs to be monitored for headworms between flowering and soft dough, when it is vulnerable.
Also, continue monitoring for aphids as there still seems to be a mixture of greenbugs, corn leaf aphids, yellow sugarcane aphids, and sugarcane aphids on sorghum. Some of the fields treated for headworms have reduced numbers of beneficials so the beneficials may not be present in sufficient numbers to help control these aphids. However, some of the fields sampled this week (Aug. 22-25) that were sprayed for headworms at least 2 weeks ago had pretty good populations of beneficials already building back up.
Photos courtesy of Dept. of Entomology, K-State Research and Extension.
Jeff Whitworth, Extension Entomology
jwhitwor@ksu.edu
Holly Schwarting, Entomology Research Associate
holly3@ksu.edu
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