Thrips, barley (Limothrips denticornis )

Thrips, barley biology & life cycle

Females emerge from overwintering during late May to early June and crawl inside the terminal leaf sheaths where they lay eggs. Eggs hatch in 4-5 days and the larvae are confined to the inner surfaces of the terminal leaf sheaths. Development from egg to adult takes about 3 weeks. Males die off and mated females overwinter in bromegrass or bluegrass sod along shelterbelts. Adults and larvae feed within the terminal sheath or the barley head, as the head is emerging from the boot. Thrips pierce the glume and the kernels. Feeding damage by thrips generally results in an increase in the number of thin or small kernels.

Identifying Thrips, barley

Thrips, barley: larvae

Pale green to pale yellow and blend in with the host plant.

Thrips, barley: adult

Dark brown to black and about 2 mm long. Females have wings fringed with hairs and bristles at the end of the pointed abdomen; males are wingless with a rounded abdomen.

Thrips, barley: management

White heads in the field will indicate thrips damage. Fields should be checked when the heads are just beginning to emerge from the sheaths and before the crop is fully headed. Peeling back the sheath will reveal dark adults on the developing head.