[Salmo]

The leaves on my gooseberry bush have been eaten by caterpillars. These are not the usual translucent green chaps with black spots but bright green.

Are they a different species of sawfly? Does anybody know?

[Trillium]

According to the middle pic here:

http://www.ars-grin.gov/cor/ribes/ribsymp/leaf8.html#A

You have gooseberry sawfly larvae. The spotty ones you describe might be leaf rollers.

[Salmo]

The images of sawflies on the RHS website are spotted
http://apps.rhs.org.uk/AdviceSearch/profile.aspx?PID=517

Here is an enlarged image of mine. The damage is certainly typical of sawfly.