No, the AQ Plus serial number will not work with Orchids Plus.
Orchids Plus is the official successor of AQ Plus, but the licensing systems are completely different.
You can request your Orchids Plus serial number directly from within the application. Simply click on "Activate" from the welcome screen, then enter the email address associated with your AOS account and press "Send My Serial Number Now"
If you have any difficulties, please see "I am a current subscriber, where is my serial number?"