Rw. Behle et al., GREENBURG (HOMOPTERA, APHIDIDAE) FEEDING EFFECTS ON NONSTRUCTURAL CARBOHYDRATES IN SORGHUM, Environmental entomology, 23(4), 1994, pp. 965-970
The effects of greenbug, Schizaphis graminum (Rondani), feeding on the
nonstructural carbohydrate concentrations of field-grown seedling and
vegetative sorghum plants, Sorghum bicolor Moench, were measured by h
igh-performance liquid chromatography. Four individual experiments wer
e completed for each of the plant growth stages to compare nonstructur
al carbohydrate concentrations between greenbug-infested and uninfeste
d plants. Greenbug-infested seedling plants tended to have greater con
centrations of nonstructural carbohydrates in the shoots and lower con
centrations in the roots when compared with uninfested plants. The con
centration of sucrose in the shoots of seedling plants increased and s
tarch in the roots decreased in a linear relationship with increasing
greenbug density. In contrast to seedling plants, roots of greenbug-in
fested vegetative plants had a greater concentration of total nonstruc
tural carbohydrates and shoots had a reduced concentration. The starch
concentration in the shoots of infested vegetative plants decreased w
ith increasing greenbug density. These results demonstrate that sorghu
m plants at these two growth stages respond differently to greenbug fe
eding in their ability to maintain nonstructural carbohydrate concentr
ations.