After last year’s invasion of sugarcane aphid (SCA), Melanaphis sacchari in sorghum, PCA’s and growers in Arizona should be on the look out for this insect this season. The SCA can be confused with other aphids that are occasionally found on sorghum. One is the corn leaf aphid, Rhopalosiphum maidis, that is small with bluish green body color with darker strips on the abdomen. The head, legs, cornicles, and antennae are black in color. The corn leaf aphid is usually found deep in the whorl of the middle leaf of preboot silage sorghum, but may also be on the underside of leaves, stems, or in panicles. Sorghum plants generally can tolerate many corn leaf aphids without being significantly damaged and control seldom is justified.
Another similar aphid is the greenbug, Schizaphis graminum. The greenbug is yellow to green in color with a dark green stripe down the middle ofits back. The greenbug can be found occasionally on sorghum and other grain crops, and there is no record of it causing significant damage in Arizona.
The following picture has the three aphids, SCA, corn leaf aphid and greenbug.