HELP! NASTY CREATURES ON MY ROSES!

HELP! HELP! HELP!
I have had my garden for 16 years but only this summer some nasty small worms or caterpillars started eating my rose leaves leaving practically nothing!
Perhaps they are larvae of ugly yellow flies I saw on my roses about a month ago. I used spray with washing up liquid but perhaps there is a better natural solution to my problem. Could anyone advise please? Thank you. See the pictures.

 

Sorry somehow I have had problems uploading pictures. Now I have managed to upload some but not all which I wanted to upload.
The worms are tiny and light green about 8-10mm long.

 

Hello Black Orchid, They are Rose Sawfly larvae. Normally, you could get rid of caterpillars by spraying with Bacillus thuringiensis (kills caterpillars only so doesn't harm other insects) but apparently it doesn't work on Sawflies Here"s a link which lists effective treatments...https://www.rhs.org.uk/advice/profile?PID=196

 

Thank you Noisette47 for identifying the nasty Sawfly larvae on my roses and thank you for the link.
Now I would be grateful if anyone can recommend some natural solution to get rid off them.
I have just read about spraying flour on Rose leaves and then washing it in 24 hours. Has anyone tried this method?

 

Thank you ARMANDII for your picture which, seems, have frightened all my potential advisers. Lol