Yes, it's a Humming-bird Hawk-moth (Macroglossum stellatarum). Its Spanish name is Esfinge colibrí.
Regarding the image quality, I think it is being forgoten in the last nonDSLR Canon cameras, in favour of a lot of options not really needed. And I'm also a victim of that fashion. I also have a S3, I love such powerful zoom, but image quality is not close to the G5 by far. (And G5 has also some problems btw...).
S3 macro hability is disapointing, far away from G5's. I know a lot of people think that Super-Macro mode in S3 is superb, but I don't agree at all. You need some distance between the camera and the subject. Being able to shot a subject which is touching the front lens in wide angle mode is not the aim of macro shots, imho.
I'm waiting for Lensmate adapters to try the S3 with full zoom and closer focus distances.We'll see. But S3 lacks hot shoe for flash, takes a century in recharging the in-camera flash and has that terrible CA! So, I will maintain the G5 with me for a long time, I guess.
Thanks all for your kind comments, very much apreciated.
Regards,
Jose