La Zygène du trèfle

Zygaena trifolii
Zygaenidae - Zygaeninae

Hétérocère diurne, commun en France. Pas toujours faciles à identifier, il suffit d'une petite tache rouge de plus ou de moins! Il en existe environ un millier dans le monde.Le lotus, sa plante hôte, fournit à ce papillon des glucosides qui se transforment en cyanure d'hydrogène (ou acide prussique), le rendant toxique pour ses prédateurs. Les larves conservent ce poison dans des glandes ou cavités et l'éjectent pour de se défendre. Le thorax est bombé près de la tête lui donnant une apparence de bossu.

The Five-spot Burnet moth:
Day-flying, commonly known as Burnet or Forester moths, with a slow fluttering flight, and with rather clubbed antennae. They are not easy to identify... it takes one red spot too many and it's the wrong one: they often qualify by the number of spots. There are about 1000 species worldwide.

The bright colours are a warning to predators that they are toxic, containing hydrogen cyanide throughout all stages of their life-cycle. These moths obtain glucosides from feeding on Birds-foot Trefoil (Lotus) so that they, themselves can use HCN as a defence. A fleshy extension of the thorax covers the head. Larvae have cavities in which they store the cyanide, and can excrete it as defensive droplets.

18/05/2010, Gers