Five spot Burnet

Zygaena trifolii:
All the burnet moths are extremely poisonous. Their bodies contain cyanide derivatives which are formed by the caterpillar from its food plants, stored up and passed on to the moth. These deadly poisons act as a deterrent to birds which learn to reject the moths as sources of food.
The five-spot burnet is found mostly in southern England where it can be exceedingly common, even on motorway embankments. It also occurs in parts of Wales and on the Isle of Man, and may fly to the same places as the six-spot burnet. There are two sub-species of the moth, differing in size, behaviour, flight time and choice of food plant, but similar in appearance. In the west of England, Wales and the Isle of Man the larger sub-species, decreta, is is found in marshy areas in late July and early august. Its cocoon is formed high up on plant stems and its caterpillar feeds on greater bird’s-foot-trefoil. In the rest of England the smaller sub-species, palustrella, flies on downland in May and June. Its cocoon is formed low down on plants and its caterpillars feed on bird’s-foot-trefoil.
The narrow bordered five-spot burnet occurs throughout England in June and July in woods and plantations.