iPhotos library - Can I delete

For the longest time I did not deal with iPhotos due to being to busy. I am now clearing space on my computer. I don't know why the libraries did not migrate when upgrading the OS but they didn't. I have now added 2007-2014 to Photos. There were in a folder entitled "picture from IPHOTO Bup" under Favorites in the Finder window. Don't remember how they got there. I back up with Timemachine. I have also backed up all the photos on another external hard drive. What can I trash now. Please see the image I took. Thank you in advance for your guidance. Frances