julia51 - is this the insect to which you refer?
These are commonly called Ebony Jewelwings, and are actually Damselflies. They are gorgeous! Population declines have been observed in parts of their range, causing them to be listed as species of conservation concern in some states.
Yes it is, thank you! They graced our little creek for a good while this summer but haven't seen them for awhile now. Terribly dry here in MD, may have something to do with it.