My raspberries didn’t bud above about 2 feet off of last year’s canes. This section of plants has done very well the past few years, I cut off the dead canes and thinned to a few canes per root at end of winter. Is this disease? Winter kill? Not enough water?
If it’s aphids you can go to Lowe’s or Home Depot and get a pack of ladybugs. Seriously. They’ll eat the aphids and leave your plants alone.
it should be noted that most ladybugs are not native to the americas and are known for killing butterfly populations. try to find local bugs that eat aphids, i suggest talking to your local gardening society