Medford, (~15 miles east of Philadelphia, PA) Burlington County, New Jersey, USA
July 11, 2006
keyed using Downie and Arnett, and matches description and photo here Great Smoky Mountains Biodiversity Inventory
Corrections welcome! Difficult to see in this photo, but there's a line of punctures with seta running between the eyes on this beetle.
This makes the eleventh Dytiscidae species found during 2 nights in July with a BioQuip UV light trap on my porch. And the nearest permanent stream or pond is over 0.5 mile away. It's been great fun!