Alder leaf beetle

The metallic blue alder leaf beetle (Agelastica alni) feeds on the leaves of alder trees. It has become common in part parts of England and Wales since 2004.

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Adult blue alder leaf beetle

Quick facts

Common name Alder leaf beetle
Scientific name Agelastica alni
Plants affected Alder (Alnus) and some other deciduous trees
Main symptoms Holes in leaves, presence of blue beetles
Most active April-July

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