This beetle may have a big, big name, Cryptocephsalus aureolus but it is a tiny insect, just 5mm or so long. As a result, although common it is frequently overlooked as it lives its life on flowers, usually the yellow flowers of the hawkweed family (like dandelions). They are a wonderful metallic green colour and it takes a close-up lens to really bring the best out of this little chap.
This is one of a large range of species collectively known as leaf beetles because they are vegetarian and feed on plants, many beetles are carnivores feeding on other insects or scarabs feeding on carrion. Not all leaf beetles are metallic green but there are some similar species to this one which are far less common. In fact, I cannot be absolutely sure this is Cryptocephsalus aureolus and not one of its close relatives; I am working on the law of probability that because Cryptocephsalus aureolus is the most common that this is the most likely one.