Zygaena is a genus of lepidopterans (butterflies) in the family Zygaenidae and subfamily Zygaeninae. It includes a hundred species, widespread in the Western Palearctic and called in French "Zygènes". The genus Zygaena was described by the Danish entomologist Johan Christian Fabricius in 1775.
The hundred or so species in the genus Zygaena are divided into three subgenera: Mesembrynus, Agrumenia and Zygaena.

Diurnal butterflies with black wings spotted with red, whose antennae are swollen in club: zygene of sweet clover, clover, vetch, scabious ... zygene are about the only butterflies that survive in the traditional cyanide bottle of the entomologists. On the other hand, they are not attacked by the usual predators(reptiles, birds, bats). These two facts have a common explanation: the zygene secretes by the base of its proboscis a highly toxic volatile liquid, based on hydrocyanic acid. The tissues of the zygene are impregnated with this acid.
The genus Zygaena is represented in France by about 25 species. There are exceptions because contrary to the others, the zygene of the scrubland is not black with red spots, but with broad red bands joined together in them. It is a species of the Mediterranean fauna.
The zygene is one of the aposematic species (a learned derivative of the ancient Greek ἀποσημαίνω, aposêmaínô " to announce by signs, to signal"), i.e., having very conspicuous and contrasting colors that would warn or bluff predators of its toxicity and serve as protection. Insects that possess in addition a chemical defense acquired by storing toxic substances of plants seem to benefit from a more effective protection, but protection, but metabolizing poisons also has an energy cost. This toxicity is due to the presence of cyanide and alkaloids of plant origin. This is a mechanism of Müllerian mimicry.
Unlike the Batesian mimicry (e.g. zoned volucella), which aims to imitate a dangerous species, the Müllerian mimicry consists in adopting the same type of signaling coloration for different toxic species.

Thus this black coloration spotted with red is shared by several species of zygens and by the scale of the ragwort.
The filipendula zygene or spirea zygene is one of the most common, probably because of its
food eclecticism. The forewings are narrow and elongated, bluish black with six distinct red spots distinct. There is a form with yellow spots. The hind wings are red bordered with black. At rest, these wings are lengthened along the body in roof. The zygene of the filipendula has long black antennas in clubs and a well developed proboscis. The body is thick, bluish black, and the wings black with red spots.
It flies rather "clumsily". It is found in many environments, dry or wet meadows, in places rich in grasses. It flies from May to August, settles on thistles, scabious, the papilionacées, the spirea. The females lay their eggs in small groups on different plants, and not necessarily on the not necessarily on the host plants of the caterpillar. This one is yellow spotted with black. It pupates in a yellow cocoon fixed on a plant where it winters."
Roxane Métayer