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Extension Entomology

Tag: western corn rootworm

Corn Update

–by Dr. Jeff Whitworth and Dr. Holly Schwarting

Lady beetles are unusually common in corn fields right now.  Most corn plants in north central Kanas are from V2-V6.  Checking corn rootworm plots revealed western corn rootworm larvae of various sizes and thus they are starting to feed enough to cause a little root damage.

CRW larvae

CRW larvae_sizes

CRW larva on root

CRW root damage

Seems like, despite the recent cooler, wetter conditions, the rootworm development is about where it usually is at this time.  Most western corn rootworms have completed the larval stage by the 1st of July, thus root damage will be completed later this month as the larvae begin to pupate in south central and north central Kansas.

 

Corn Pest Update

–by Dr. Jeff Whitworth and Dr. Holly Schwarting

Checking corn fields between rains indicates some insect activity.  The most visible seems to be corn earworm larvae.  The fields we checked in north central Kansas were in the 8-9 leaf stage and the corn earworm larvae had probably been feeding for about a week.  However, the feeding is only noticed after the leaves unfurl as the larvae are hidden inside the furled leaves.

 

CEW larva

Checking corn fields between rains indicates some insect activity.  The most visible seems to be corn earworm larvae.  The fields we checked in north central Kansas were in the 8-9 leaf stage and the corn earworm larvae had probably been feeding for about a week.  However, the feeding is only noticed after the leaves unfurl as the larvae are hidden inside the furled leaves.

Ragged leaves corn

We also found western corn rootworm (WCRW) larvae feeding on corn roots.  This field was sampled last weekend but no larvae were detected.  However, in this same field, the larvae hatched and have fed on the roots as seen in the picture.  Just in the last 3-4 days, larval feeding has caused some root damage.

CRW larva and damage

CRW larva