Cockchafers (Melanotha melanotha) have lots of other nick names: May bugs is probably the commonest – although they’re not a “bug” in the true sense of the word, they’re a beetle.
In some areas, their larvae are an agricultural and horticultural pest. They live in the soil for several years, munching on plant roots. Here, in north Wales, they are relatively uncommon.
The Natural History Museum and Buglife both have lots of information about cockchafers, including how they (yes, the bugs) were once taken to court in France and ordered to leave the city of Avignon or else be killed!