Longitarsus luridus

After working on translating the key to genus Longitarsus to identify all the British species, it turns out that the species I had collected earlier in the week was the commonest one in the country.  Still the world now has a reasonable illustrated key to the British species of the genus at https://sites.google.com/site/mikesinsectkeys/Home/keys-to-coleoptera/chrysomelidae.  It does seem that host plant is going to be very important in the identification and I hope to do some targeted collection to increase my familiarity with the genus.