There has been a great increase in the number of Nomada solitary bees in my garden this year. Nomada bees are cleptoparasites because they lay their eggs in the nest cells of other bees. Each nomada species targets a specific bees species. Nomada bees could easily be mistaken for wasps.

This is a Nomada goodeniana.

This one may be a Nomada signata but the picture is not so clear for ID purposes.