Common grain ground beetle – Zabrus tenebrioides

This is the most dangerous pest in cereal crops. The common cereal leaf beetle (Zabrus tenebrioides) attacks wheat, barley, maize, oats and a number of cereal grasses.

In dry and warm summers, a strong development of the adults is observed. One of the reasons for their mass occurrence in recent years is the monoculture cultivation of cereal crops. Damage caused by the adults is insignificant. They appear as early as June and persist until late autumn. The beetles feed on wheat and barley grains in the milk stage. They gnaw them and cause their shedding. During hot periods they burrow into the soil. After the rains in September they emerge on the soil surface, copulate and lay eggs at a depth of 5 cm under soil clods, in clusters of 20 eggs. They prefer to lay in areas infested with couch grass, therefore the damage is patchy.

The larvae bore tunnels up to 40 cm deep, where they spend the day, and emerge to feed at night. They gnaw off the sprouts of the plants; on young plants they chew the leaves and suck out the sap; subsequently the leaves turn brown, dry out and resemble small bunches of fibers. In cases of low infestation the stand thins out, and under mass attack the entire crop may be destroyed and ploughing up becomes necessary.

damage caused by cereal leaf beetle

What control measures are used against cereal leaf beetles?

The following measures must be observed: proper crop rotation, timely soil cultivation and destruction of cereal weeds, especially couch grass. In this way the density of the larvae is significantly reduced and insecticide treatments are saved. Chemical control is carried out at the economic injury level in the emergence and tillering growth stages - wheat - 3 larvae/sq. m, barley - 4 larvae/sq. m.

You can use the following plant protection products for the control of cereal leaf beetles:

Mospilan 20 SP - 12.5 g/da; Decis 100 EC - 7.5 ml/da; Force 20 CS – 100 ml product/100 kg seed, Austral Plus – 500 ml product/100 kg seed