NORMAN — Several significant rain events have finally fallen across portions of Oklahoma. While this is a blessing for agriculture producers in these areas, others have been less fortunate. Areas like these suffering recently from a lack of major rainfall may experience high grasshopper infestations this summer.
“It’s not just the western parts of the state; there are pockets in eastern Oklahoma wherein the rain has just not fallen at the right time, even with recent rainfall in June,” said Tom Royer, Oklahoma State University Extension entomologist. “Agricultural producers need to be taking proper preventative steps between now and July 1.”
Royer said waiting until a grasshopper sprouts wings makes effective control a “hit-and-miss” prospect and a more expensive control endeavor at any rate.
Grasshoppers can eat 25 to 50 percent of their body weight in forage a day. In contrast, a steer will eat 1.5 percent to 2 percent of its body weight in forage a day.
Depending on the level of infestation, grasshoppers can have a significant negative effect on the health and availability of a producer’s pasture resources.
The first step is for producers to assess grasshopper population numbers on their properties. Producers should study an area about one-square-yard in size as he or she walks through the pasture, counting the number of grasshoppers. Repeat the process three or four times, leaving 75 feet between areas of study.
Once a producer has a sense of grasshopper population numbers, he or she should access OSU Extension Facts EPP-7196, “Grasshopper Management in Rangeland, Pastures and Crops,” available at osufacts.okstate.edu. These will help producers decide whether treatment is profitable or not.
The fact sheet has easy-to-follow suggested treatment thresholds, as well as a discussion on Reduced Agent and Area Treatment options using Dimilin®. Besiege® and Prevathon® are two relatively new insecticides registered for grasshopper control on rangeland and pastures.