Length: 8.5 - 10.0 mm
Amphasia interstitialis can be found under rocks and logs and in leaf litter.
In a 1961 note in The Coleopterists Bulletin, R.E. Woodruff reported that an oatmeal trail placed in the woods at night in Ohio attracted Amphasia interstitialis, as well as Carabids in the genera Bembidion, Dicaelus, and Harpalus.
The map at the bottom of this page shows the states and provinces with records of Amphasia interstitialis in blue-green.
Photo data: 4 April 2019. Under a rock. Ruraldale, Upshur County, West Virginia.
GPS data: 39.0721, -80.2443. Elevation 353 meters above sea level.