I'm sure Mike Hackston's keys have been mentioned before and they're definitely listed on Richard Comont's list of resources but there's little notification when he adds new ones. I took a look today after last checking it in mid January and several keys have been added as well as some older ones updated. The new ones are:

• Species of Bostrichidae (Coleoptera)
• Species of Gyrinidae (Coleoptera)
• Several keys to species of various subfamilies of Chrysomelidae (Coleoptera)
• Species of Chaoboridae (aka Phantom midges) (Diptera)
• Species of Pamphilioidea (Hymenoptera: Symphyta)
• Key to 25 common species of British Psylloidea (Hemiptera: Sternorrhyncha)

https://sites.google.com/site/mikesinsectkeys/Home