Insects in the Field this Week – 5/12/07

There are a number of insects to be on the lookout for this week in the Grain Sorghum, Cotton and Soybeans of the Texas Coast.

Grain Sorghum

Sugarcane Aphids near Corpus Christi

Grain sorghum fields vary widely with regard to crop maturity. The older fields are blooming and the youngest fields are 4-6 leaf.

All sorghum fields should be monitored weekly for insect pests. The one insect that can cause problems season long is the Sugarcane Aphid. I have found them in low numbers along field margins and expect to see populations rise in the near future.

I looked at a field in Corpus Christi this week with very high number of sugarcane aphids. While I do not expect to see this across all fields, some fields in our area will probably have economic populations requiring treatment.

Blooming sorghum should be monitored for Soghum Midge and Stink Bugs. When I stop on road sides to check fields I am also looking in the grass adjacent to the crops. Most of the roadside grass that is producing seed also has rice stink bugs. Sorghum is susceptible to stink bugs from bloom to hard dough. The economic threshold calculator for rice stink bugs is HERE.

Rice Stink Bug on Bluestem.


Cotton maturity ranges from squaring to bloom.  The cotton fleahopper is no longer considered a pest after bloom. However, following bloom, we need to begin to scout for stink bugs and verde plant bugs.


Some soybeans are beginning to bloom.  The most damaging insect I have found in soybeans on the coast is the red-banded stink bug.  I had two of these brought to me last week on a volunteer soybean plant.  Blooming soybeans should be scouted for stink bugs.  Treatment threshold for all stink bugs is 36 per 100 sweeps with a sweep net or 1 per foot of row with a drop cloth.  For the Red Banded Stink Bug, use an ET of 16 per 100 sweeps or 1 per 3 feet of row.

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