Flea Beetle

Chrysomelidae; Galerucinae; Unidentified Alticini. When I first tried to identify this beetle, I noticed that it had some features in common with Pyrrhalta nigromarginata (Jacoby, 1885), but the more I looked, the more differences I saw and I have not yet found its true identity. However, the pictures show something rather unusual and I thought I would upload this spotting to find out if anyone has seen anything similar. I am referring to what appears to be a small insect biting the antennae of the Flea Beetle. This seems rather strange. Any ideas ??