Why are there blue wasps in my Japanese maple?

Blue wasps, likely referring to blue mud daubers or similar species, may be attracted to your Japanese maple for several reasons. They often seek out sheltered areas for nesting, and the tree's structure can provide ideal locations. Additionally, if your maple is producing sap or has aphids, these can attract wasps looking for food sources. It's generally not a cause for concern, as they are typically solitary and not aggressive.