Reed Beetles Chrysomelidae

Reed Beetles are a group within the large family of Leaf Beetles Chrysomelidae. They are often metallic and associated with plants of draw down zones such as water iris and bur-reed, on which they feed. The FSC AidGap key to British Water Beetles by Laurie Friday is useful for determining them to genus level. Species level identification is more problematic, as there are more species present in the Touraine Loire Valley than in Britain.

Plateumaris sericea: Females are copper coloured, males are dark irridescent blue green. According to John Bratton, who mispent his youth surveying Reed Beetles in the Brenne, the best diagnostic for distinguishing the genus Plateumaris from other Reed Beetles is 'a sort of folding over of the elytral suture towards the hind end' (see illustration on p 87 of the AidGap Key). Note also the spur on the hind femur. There are 6 species of Plateumaris possible in the Touraine Loire Valley, however other Plateumaris spp are not metallic and/or have pale legs.
Plateumaris sericea congregate and mate on a Yellow Iris Iris pseudacorus on the edge of the Etang Vieux in the Brenne, May. Many thanks to John Bratton for identifying these beetles.

Two males pursue a female.

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