Sunn pest (Eurygaster integriceps) is a sap-sucking bug that feeds on grain crops, damaging leaves, stems and grain heads. Feeding damage is caused by the injection of toxins into the plant by their piercing and sucking mouthparts that can result in grain abortion and, in large infestations, plant death. In addition, the baking quality of the flour produced by infected grains is substantially reduced.
Sunn pest feeds on wheat, durum, rye, oats, sorghum, and barley.
Adults (10-13 mm long) vary in colour from greyish-brown to reddish-brown and have a wide triangular head and oval-shaped body. They have needle-like sap-sucking mouthparts. Their wings are completely hidden by a hardened ‘shield’ that covers most of the body and is rounded on the bottom edge. Juveniles (nymphs) are rounder in shape and normally dark brown to black. Eggs are light green and are laid in two even rows on host plant leaves, and darken near hatching.
There are several similar sap-sucking shield bugs. Differences in the ‘shield’ colouration differentiate the insects in this group.
Sunn pest is most easily seen in spring on wheat heads. In the northern hemisphere, in the initial stages of infestation the insects are more abundant on the edge of the crop, near bushes and trees where they over-winter. When high numbers of insects feed on the crop, the plants can develop ‘white-heads’.
The symptoms of a sunn pest infestation include yellowing and dieback of the stem and leaves, and stunting of the growth of tips and buds.
Feeding on other parts of the plant causes abnormal flower formation and discoloration. Feeding before grains develop can result in grain abortion or, if feeding occurs only after development, the grains are left shrivelled, discoloured (white) and/or empty.
Both adults and nymphs are capable of feeding on dry grain, providing moisture is present.
Sunn pests have wings (hidden under the shield) and can fly over large distances. Adults migrate up to 250 km, particularly in areas with continuous crops. Sunn pest can also survive long periods without food in soil and can be spread with the movement of machinery or equipment.
Sunn pest is found in parts of North Africa, West and Central Asia and Eastern Europe.
Check your farm frequently for the presence of new pests and unusual symptoms. Make sure you are familiar with common grain pests so you can tell if you see something different.
If you see anything unusual, call the Exotic Plant Pest Hotline on 1800 084 881.
Check your farm frequently for the presence of new pests and unusual symptoms. Make sure you are familiar with common grain pests so you can tell if you see something different.
If you see anything unusual, call the Exotic Plant Pest Hotline on 1800 084 881.
