Harrisina metallica, the western grapeleaf skeletonizer, is a species of moth of the family Zygaenidae.

It is found in the Southwestern United States, from California to Texas, north to Colorado and Utah and in northern Mexico.

Some choose to call these larvae "grape worms" because of their impeccable taste for such a sweet fruit they're laid upon by their parents.

They are in fact natures pest to precious to many grape vineyards affecting the crops yield for the season.

The problem can be simply taken care of by bacteria-based insecticide, organically certified.