Extension doesn't collect this information so we don't have a list to share, though most pest control professionals probably have experience dealing with wasp nest removals. (Generally, this will simply involve spraying it with wasp spray, or potentially removing it manually after first vacuuming-up the workers to reduce the threat of stings.) Some beekeepers offer to remove wasps, but not many; the Maryland State Beekeepers Association has a list of members that provide bee removal services (and wasps, where noted on the linked page).

Bumble bees have annual nests, meaning that, like the social wasps linked above, they only use a nest for one year. Most of its members die out each autumn (or sooner), and only a handful of individuals overwinter, dispersing in the spring to start new nests elsewhere. Sometimes a new nest happens to be formed near the old one, if the queen bee finds the habitat suitable, but not always. Perhaps, if what you were seeing was bumble bees and not carpenter bees (though both are also possible), something affected how many queens were exploring the yard for nest sites in spring. Leaf litter can shelter them, so if removed, will tend to make nesting less likely. Flower abundance and pesticide use can also influence how many bumble bees and carpenter bees visit an area. Natural population fluctuations are also possible, having little to do with human activities. If you want to attract these and other pollinators, our Pollinator Gardens page can be a good starting point.

Miri