Barley thrips

Barley thrips

Name: Limothrips denticornis

Alias: Barley thrips are quite often hard to notice due to their size. They are approximately the size of pencil eraser shavings but can cause a lot of damage. They are usually darker in color, but color is not a good identifier because their color can vary from yellow to black. They’re usually winged, but they may be wingless. They are almost all female, and they can reproduce quite rapidly, having several generations each growing season. The immature nymph stages cause more damage than the adults.

Crimes: They feed on grains and grass crops causing the foliage to turn a dusty white color. In large populations, they can cause significant yield reduction.

Redeeming Qualities: none known.

Sentence: Barley thrips cause the most damage after drought, so the most effective way to control them would be to control the weather and always make sure you never have a drought. If your rain stick isn’t working for some reason, other options are available. Monitor fields regularly for barley thrips by unrolling the leaf sheaths from the stem and look for little dark bugs. Their presence alone may not merit control unless populations are excessive. If the population does call for control options, there are a wide variety of pesticides that are available for use in grain crops. Fastac EC, Mustang or Stallion are all viable options. However, thrips can rebound their populations very quickly, so if their predators are removed with a pesticide application then you may be perpetuating the problem. As you monitor for thrips, also monitor for beneficial bugs such as ladybeetles, lacewings and predatory thrips.

For more information on dangerous and beneficial bugs, call UI Extension educator Joseph Sagers at 208-270-4031 or email jsagers@uidaho.edu.