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Cereal leaf beetle

Adult beetles are 5mm long, with a black head, red thorax and shining blue/green metallic abdomen.  The grubs are small and slug-like with a humped back, but have 3 sets of legs near the head.

Both the grubs and the adult beetles feed on the veins on the upper leaves of the cereal or grass plant, stripping out the chlorophyll and leaving a 'window' like transparent patch along the leaf.  They are a common pest amongst cereals in general, particularly oats.

Overwintering adults appear any time from April and from mid summer lay orange coloured eggs on the upper leaves of host plants.  Ten days later, the larvae emerge and begin feasting on the plant.  After 3 weeks the larvae move to the soil to pupate and return to feast on host plants before moving during autumn to a site to overwinter.


cereal leaf with beetle

A rich natural biodiversity within the cropping area should provide sufficient predators to manage the pests and prevent significant damage.  If the flag leaves are showing signs of being badly stripped, an insecticide can be employed to prevent significant damage.

Visit our Crop Health Updates webpage for timely, monthly updates on cereal pests & diseases.  We have information about Integrated Pest Management within our Biodiversity section of the web site.

Related information

Cereal leaf beetle, June 2019

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