Found two on Solanum dulcamara. Both had their iridescence dulled by moisture from the rain, but otherwise behaved just like the normal Polydrusus impressifrons. However, both also walked around with their jaws wide open, and though I have observed P. impressifrons for many years, this is the first time I've seen this sort of behavior. This and their wetness initially led me to think that I had encountered something different, but keying concluded that these are just the regular P. impressifrons (although one individual measured 6 mm - beyond the size range given by the key). Still, I wonder why both of these individuals, which were on different parts of the plant, were simultaneously doing something that I've never seen before - and continue to do so long after I have captured them.