Midges are cosmopolitan. Bloodworms are commonly of the genus Chironomus.. and fun-fact the red colour is haemoglobin which binds oxygen (as it does in our blood) allowing midge larvae to live in low oxygen environments like the sludge in the bottom of a fish-food bucket.
Thats most interesting, I didn't think we had midges here in SE England, but maybe just get a small number. We certainly get mosquito here though as there are 2 lakes in the grounds, I have friends coming sunday and they will be sent to get some daphnia and mosquito larvae, they usually take a tub full home for their fish as well! I will pass on the tip about the jelly if they see any in their bucket!
Bloodworms are larvae of midges (mosquito-like flies without the "pronger")
The adults lay eggs in the water that look like little sacks of jelly. You sometimes see them hanging from the water surface or stuck to the edges of the bucket. You can wipe the "jelly" off and put it in your tank and when the larvae hatch they are great fry food.... but if you dont have enough fish to eat them they may live in the tank and emerge to fly around your house.