Lachnaia (genus) & juvenile grasshopper

( a juvenile grasshopper in the secondary picture)

this one: 
Chrysomelidae family
Lachnaia genus
the specific Species.... ??.. bah
after some research looks like there are at least 4 different species in the Iberian Peninsula... and I couldn't see any spottable difference between them, by only looking at pictures... apparently they can be differentiate ... by the penis. So forget about it...