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Extension Entomology

Tag: decline

Sugarcane Aphids

–by Dr. Jeff Whitworth and Dr. Holly Schwarting

Sugarcane aphids (SCA) colonies have rapidly declined in some fields in north central Kansas, slowly declined in others, but actually increased somewhat in other fields.  In one field, approximately 90% of all previous SCA’s are gone and enormous numbers of lacewing adults remain (see pics).  However, prior to the latest cold front, most top leaves had winged aphids with nymphs.  This means, evidently, that they are still migrating in and trying to establish colonies.  However, with huge numbers of beneficials now present, it seems unlikely that they will be successful, especially with the recent cooler weather.  Everywhere that SCA colonies became established, they produced honeydew, which coated the sorghum leaves, and was then covered with a dark sooty mold.  However, when the colonies are eliminated the honeydew is no longer sticky and the black mold becomes dry and washes off (see pic).

brown lacewing

green lacewing

 

old honeydew