Pocantico Hills, Westchester County, New York, USA August 18, 2016 Size: 1/5"
Could this be Lasioglossum versatum?
This bee has a greenish-bronze head and thorax and a dark abdomen covered with sparse light-colored hairs. The tegulae are brown. The pronotum has sharply projecting right angles. The head and thorax are pitted. Feeding on goldenrod.