Crested Wheatgrass Suffers From Black Grass Bugs

By PR Extension Office

The crested wheatgrass has responded to the moisture and warmer temperatures, exploding in growth. Unfortunately, the black grass bug population has also exploded and is sucking the grass dry, according to Mary Rumph, Powder River Extension Agent.

Most notable is the “anemic” look to the grass in the roadside ditches, an area where it should be a healthy green color. The black grass bug literally “sucks the juices” out of the leaves, leaving a whitened, tough and stringy leaf. The black grass bug (labops hesperius) is one of the earliest pests to emerge in the spring and is able to feed in very cold weather. The young nymphs hatch from eggs that have been inserted into grass stems. The nymphs molt five times during their development into adults, feeding the entire time.

The insects aren’t regarded as too great of a threat unless they move into crested wheat hay meadows which they have been known to do in recent years, commented Rumph. The best control is done while they are still along the roadsides in a concentrated area. Local producers have found that low rates of malathion (1 to 1 ½ pints per acre) are effective for three to four years of control. The insecticide Sevin is labeled for black grass bug control.

“They are fairly easy to kill,” added Rumph. The reason they are first seen in the ditches along the highway is due to the eggs laid in grass that wasn’t grazed heavily. Intense grazing is one of the recommended biological controls.