The wheat jointworm, Tetramesa tritici (Fitch), is most common in eastern North America and the Pacific Northwest. Once considered one of the major wheat pests, on a par with Hessian fly, it is now thought to be of only minor importance. The wheat jointworm overwinters in the pupal stage within stem galls in wheat stubble. The small black adult wasps gnaw their way out of the pupal chambers in April and May and spend the following month in wheat laying their eggs in wheat stems just above one of the nodes. The small white larvae form cells in the stem wall where they feed on plant sap. The swelling formed by the presence of the cell is referred to as a stem gall. Larvae cease feeding at about the time of wheat ripening.
Larval feeding causes the formation of small stem galls, resulting in malformed tillers prone to breakage.
No applied biological controls exist for the control of wheat jointworm.
Recommended cultural controls include late fall or early spring stubble destruction and growing the current year's crop at some distance from the previous year's crop.
No effective insecticide treatments are known for the wheat jointworm.
Categories: Small grains, Insects, Wheat Jointworm
Date: 04/16/2004