Thrips and Fleahoppers

Adult Cotton Fleahopper
Photo: Kate Harrell

  The dry weather lately has allowed thrips populations to thrive, and I've seen a fair number of them in the field. Later planted and replanted cotton is still vulnerable to thrips, and will be until the 5th true leaf stage. Seed treatments will have worn off 2-3 weeks after planting. The threshold for thrips is an average of 1 thrips per true leaf.
  I saw my first cotton fleahopper of the season near El Toro in Jackson county. They are beginning to pop up all around, and the earlier planted cotton is starting to square. This insect feeds on plant materials, and will feed on cotton squares. Keep a sharp eye out for this insect, the adults are very flighty and are often easily scattered when walking fields. I try not to let my shadow hit a plant before I get close enough to look at it so I can see the adults before they fly. On the left, the adult is in the top photo, and the nymph on the bottom. The nymphs of these insects are also quite small, about the size of an aphid. They are also a pale green color, but lack wings. They nymphs can be easy to confuse with the nymphs of minute pirate bugs, but the minute pirate bug nymphs tend to be orange and are shaped more like a teardrop. Fleahopper nymphs lack the bands on the antennae a few other species of plant bugs have, and have a similar body shape to the adult bug.
  Fleahopper feeding will cause squares to drop. Plants can recover for and compensate for some square loss, but the threshold for fleahoppers is 15-20 per 100 plants.
  The chart below contains insecticide suggestions from cottonbugs.tamu.edu (also a good resource) for reference if you have fleahoppers at the action threshold.

  I am currently still on the lookout for sugarcane aphids and for corn earworms in refuge or non bt corn or sorghum. If you've got either of these insects, feel free to give me a call, I would really appreciate it.

Sincerely,

Kate

Looking for more information? Check out the New Cotton Insect Guide