Our weeping cherry has tiny black ladybird like beetles in clusters on the tips of the leaves and the branches are now developing jelly like masses on them. What do you think this may be?
Certified GKH Gardening Expert
It sounds like your tree is suffering from a Canker. You can control the spread of this disease by pruning.
The black insects are likely Black Aphids.
Here are some articles that will help you with these issues.