I found this on two varieties of raspberry (Dormanred and Blackhawk) and one blackberry (Arapaho) so far.

A thread here from last May pointed me in the right direction- raspberry cane borer. These bugs make two girdling scars when they lay their eggs, causing the tips to wilt. I found a place with pictures of this and wanted to share the link.

I'm experimenting trying to root the tips I cut off. They perked up in water, so I dipped them in Rootone and potted them. Will let you know how this works out.

Do you think that spraying with insecticide is needed?

thanks.

Here is a link that might be useful: raspberry pests