Alder Leaf Beetle

The Alder Leaf Beetle, is a deep metallic blue Leaf Beetle. It was once considered extinct in Britain, but was found in Manchester in 2004 and is now on the increase in the North West of England. It has recently undergone a sudden expansion of range and in 2018 it was found to have spread to North Wales.

The beetle and the beetle’s larvae feed on the the leaves of Alder but can be found on Hazel, Downy Birch and Goat Willow if there is a shortage of food. They cause the leaves to turn skeletal, with large holes and gaps, from the end of April through to October.

The Adult Alder Leaf Beetle can be found from April to July and again in September and early October. Adults overwinter in soil and leaf litter near host trees, emerging in April. Adults can fly, but rarely do.

The larvae develop on Alder leaves, going through three stages and pupation occurs in an earth cell just below the ground surface, or in leaf litter.