A minuscule pest few Texas farmers had ever heard of three years ago has quickly gained notoriety as the most important insect pest of grain and forage sorghum in Texas, said an expert entomologist. Allen Knutson.
“Grain and forage sorghum producers can now monitor the progression of the sugarcane aphid across Texas via an online mapping program conducted by AgriLife Extension in cooperation with Kansas State University,” Knutson said.
The sugarcane aphid distribution map can be accessed at https://www.myfields.info.
“Growers and consultants can use the map to determine where sugarcane aphids have been found in sorghum fields across the state and anticipate the need to scout fields to determine aphid infestation levels in their area.”
Since it was first discovered feeding on sorghum in 2013, the sugar cane aphid has become an annual pest, infesting both grain and forage sorghums. The tiny insect sucks plant sap, causing leaves to yellow and die, thus reducing yields. In addition to the feeding damage to the crop, the aphids’ sticky excrement called honeydew, can actually become so heavy that it can gum up combines and forage harvesters, rendering them inoperable.
Once sugarcane aphid is found in a county, it is posted online through the MyFields.info.
Dr. Robert Bowling, AgriLife Extension entomologist at Corpus Christi, confirmed that by April 28, the pest had been documented on sorghum in 15 counties in the Lower Rio Grande Valley and Lower Gulf Coast.
How can such a tiny insect cover so many miles so quickly? Knutson said adult aphids with wings develop in the aphid colony as it becomes crowded and food quality declines. Although these winged aphids are weak fliers, it’s believed they are carried by the wind from field to field and over very long distances.
“Sugarcane aphid infestations, especially in Central and West Texas, likely result from long distance dispersal of wind-blown aphids from South Texas,” he said. “By using the sugarcane aphid mapping site, growers and consultants can monitor the movement of sugarcane aphids as they move across the state. The mapping project also supports the U.S. Department of Agriculture’s Agricultural Research Service program studying the long-distance movement of sugarcane aphid from South Texas to Oklahoma and Kansas.”
Insecticides are effective for control of sugarcane aphid, but Bowling said applications must be properly timed before aphid numbers begin to rapidly increase and damage the crop. “It’s important to remember these aphids can build their populations to extremely large numbers in a very short time, so scout early and don’t delay treatments once infestations reach the crop-damage threshold,” Bowling said. “Using the Sugarcane Aphid Distribution Map is a classic case of forewarned is forearmed.”
Lonnie Jenschke is an Erath County extension agent.