This is a male specimen of an introduced species in North America. These bees are becoming extremely numerous here in Illinois - they are large and aggressive towards other insects competing for flower nectar.
This is a female specimen of an introduced (invasive) species in North America. These bees are becoming extremely numerous here in Illinois - they are large and aggressive towards other insects competing for flower nectar - in this case, the crown vetch plant - Coronilla varia, itself an invasive species.