What is this?

What is this?

Observation - What is this?. Description: I spotted what looked like a small green bug on the leaf until I photographed it and saw what a beauty this is. Body size approx 4-5mm, with antennae 2 to 3 times body length. I've trawled through my field guides but can't figure out what type of insect

I spotted what looked like a small green bug on the leaf until I photographed it and saw what a beauty this is. Body size approx 4-5mm, with antennae 2 to 3 times body length. I've trawled through my field guides but can't figure out what type of insect this is! Help please - any ideas?