Be on the Lookout for Sugarcane Aphids on Sorghum
The sugarcane aphid, Melanaphis sacchari, was first reported damaging grain sorghum in Louisiana and Texas in 2013. Previously, it had only been known as a pest of sugarcane. It can also feed on other sorghum species such as forage sorghum, shattercane, and Johnson grass. This aphid pest has been spreading across the southern U.S. since then, and last year was found in sorghum in Virginia and as far north as Kansas. It has not been reported in Nebraska. Low populations have recently been reported in southern Kansas.
Grain sorghum producers should check their fields for the potential presence of this insect in Nebraska. Aphid colonies are initially most common on the undersides of lower leaves but can be found higher in the canopy as populations increase. The presence of dark sooty mold growing on the sugary secretions of aphids called "honeydew" also can be an indicator of their presence.The sugarcane aphid is light yellow to gray in color, with dark cornicles (“tail-pipes”) at the end of the body and dark tarsi (feet). Adult aphids can be winged or wingless.
The other two common sorghum aphids in Nebraska, the greenbug and corn leaf aphid have significantly different coloration and markings (Figure 2). Another common aphid on weedy and wild grasses that looks similar is the yellow sugarcane aphid. This aphid is not a common pest of sorghum in Nebraska, but can reach economic numbers in southern states. It can occasionally be found in large colonies on foxtail grasses (e.g., common foxtail).
If you find aphids on sorghum and suspect they may be sugarcane aphids, please submit a sample to the UNL Plant and Pest Diagnostic Clinic so we can document the presence of this aphid in Nebraska.
We will provide additional information on management options when the aphid is known to occur in Nebraska.