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Mystery Insect (07/16/20)

This tiny, white larva was found feeding inside the developing tassel of corn located next to a shelterbelt.

This tiny, white larva was found feeding inside the developing tassel of corn located next to a shelterbelt. The corn field was north of Bismarck and near the Missouri River Basin. Is it a pest?

 

Larva is inside yellow circle.

 

ent.8

 

Answer:  This is the larva of the wheat stem maggot, which tunnels in the stems of wheat causing white, infertile heads. Growers and agronomists often see the white heads of wheat that easily pull out. If you look at the base of stem, it is chewed off. In this case, wheat stem maggot was feeding on the developing whorl of the corn plant, which was severely stunted or destroyed. This is becoming more common, especially when a small grain cover crop like rye was planted before the corn or the previous crop was a small grain crop last year (a source of wheat stem maggot populations). So far, it has been localized near Bismarck and not an economic pest problem. Please watch for it and let me know if see more wheat stem maggot feeding in corn.

Janet J. Knodel

Extension Entomologist

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