The striped abdomen may be a clever adaptation to fool preditors into thinking she's a bee and might sting. Actually she is stingless. This gal can be an excellent pollinator. She has very large eyes thus mimicking the honeybee drone, but she's a fly, with only one pair of wings, not a bee, with two pairs. Many are good pollinators.
None are a threat to humans.
Here are a few representatives. Lots more on Solitary Bees as Alternative Pollinators Leafcutter bee on vervain. Note yellow pollen on her belly. More Digger Bee Pics Halicitid Bee on Aster Note green thorax. Many halictids are entirely or partly green.