These are assassin bug nymphs. They are excellent generalist predators of pest insects and they are good to have around a garden. They have used your tree as a place to lay their egg clusters and they are not harmful to the tree. They also are harmless to people but it's best not to handle the adult bugs. They have long, sharp "beaks" that can pierce skin. Here is our web page with more information about assassin bugs.

https://extension.umd.edu/resource/assassin-bugs

Christa

It would be fine if want to move some to your vegetable garden, although they will seek prey on their own (and may not stay where you put them). They will not bite you unless they are actively picked up and handled. Wear garden gloves. Or just let them find their way naturally. They do not seek to bite people as mosquitoes do, so it's fine to have them around your yard and observe from a distance rather than try to handle them.

If you are seeing tomato pests and/or other problems around your vegetable garden, be sure to visit our website for more information throughout the growing season. 

https://extension.umd.edu/resource/tomatoes

https://extension.umd.edu/programs/environment-natural-resources/program-areas/home-and-garden-information-center/food-gardening/vegetables-home-garden

Christa