Kansas State University

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Extension Entomology

Tag: infested

Sorghum Update

–by Jeff Whitworth and Holly Schwarting

Double cropped sorghum in north central KS seems to have a significant infestation of “ragworms”.  The larvae are a combination of fall armyworms and corn earworms and are of various sizes.

corn earworm_ragworm

windowpane ragwormfall armyworm_ragworm

 

Leaf feeding in the whorl by either species is highly visible but should not have a significant effect on the plants or yield.

windowpane ragworm

ragworm feeding

Also, most fields in north central KS are infested with aphids.  Corn leaf aphids can produce a great deal of honeydew but mostly in the whorls.  This honeydew may retard head extension but usually does not affect many plants over a large area.

corn leaf aphids

greenbugs

Yellow sugarcane aphids

Also found greenbugs and yellow sugarcane aphids.  None of the invasive sugarcane aphids were detected in north central Kansas.  However, many beneficials are, and will continue to be, present in sorghum fields as evidenced by the numerous green lacewing eggs and lady beetle eggs.

lacewing eggs

Wheat Update

By — Dr. Jeff Whitworth, Dr. Holly Schwarting

Wheat fields sampled in NC Kansas over the last week have diminishing populations of aphids.  Many fields had to be sampled relatively vigorously to find any aphids.  However, lady beetles are still quite plentiful which should bode well for not allowing the aphid populations to rebound.

Scattered white heads are starting to be easily distinguished in the green wheat.  If the stem pulls out easily, with some apparent feeding in the stem, this is from the wheat stem maggot.

wheat stem maggot

The number of infested stems in always negligible relative to yield loss but often causes concern because of the easily noticed white heads.