Dead loganberry cane? Are caterpillars damaging?

[Matt84]

I purchased a a few fruit canes some time ago and they all seem to be doing well. Unfortunately I had a lot of caterpillars on my loganberry plant(well on the one shoot that had come up) So I decided to take it off and place the caterpillars in a glass tank as I didnt want to kill them and was interested to see which type of caterpillar they were. However after taking this shoot off there was no more growth on the loganberry cane and still hasn't been, have I killed it off or is there anyway I can instigate new growth ??

Coincidentally I have a lot of caterpillars on my raspberry bush, are they detrimental to the plant? As long as they dont eat the fruit i'm not fussed as I am trying to create a wildlife friendly garden anyway(As long as they dont take too much of my produce!)

Any tips would be appreciated.

Thanks

[Two_Sheds]

Where are you? Can you put your location into your profile please?

It sound like Raspberry Sawfly Crops | Insects | Raspberry Sawfly (Monophadnoides geniculatus) | Manitoba Agriculture, Food and Rural Initiatives | Province of Manitoba

I can't find out if it occurs in UK though