Trichodes spp Checkered Beetles


In the Loire Valley there are two striking checkered beetles that look very similar and are quite commonly encountered during the summer. Both are red and blue-black, with black heads and rather hairy. Both parasitise bees (wild solitary bees, not domesticated honey bees) and are called Clairon des abeilles in French. The adult beetles are usually found visiting flowers, often umbellifers or daisies, where they will eat pollen and hunt small insects.

Trichodes alvearius
Found mainly in the Paris Basin, central lowland France and the south-east Mediterranean coast, more rarely in the south-west of France, and rare in the north-west. This species can be distinguished by the upper black band being V-shaped, and the tip of the elytrae being red ie the lower black band does not quite reach the tip. The elytrae have a fine continuous black line all the way down the inner edge ie down the middle of the beetle's back.

Trichodes alvearius on Field Scabious Knautia arvensis. Indre et Loire. France. Photo by Loire Valley Time Travel.
Trichodes alvearius on Field Scabious Knautia arvensis in my orchard, July 2020.

Trichodes apiarius
Scattered records throughout France, with a gap between Nantes and Bordeaux along the Atlantic coast, and a concentration of records on the south-east Mediterranean coast. They can be identified by their upper black band being more or less straight across (definitely not forming a V), and their definitely black elytrae tips.

Trichodes apiarius on Field Scabious Knautia arvensis. Indre et Loire. France. Photo by Loire Valley Time Travel.
Trichodes apiarius on Field Scabious Knautia arvensis in my orchard, July 2020.

A key to all the Trichodes species in France is available here [link].

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