There are more than 60 species of wasps in genus Ammophila in North America, and it can be difficult to identify them to species. They tend to be medium-sized and generally black, with some amount of orange on the abdomen (the hindmost part of the body). There is a narrow constriction between the thorax and abdomen (thus the name "thread-waisted"). The abdomen is straight or points downward at the tip (it does not point upward). Males are more slender than females and usually have less orange or red color than the females.
Similar species: Ammophila is just one genus in the large and diverse thread-waisted wasp family. Other thread-waisted wasps include the genera Chlorion, Podium, Chalybion and Sceliphron (both called mud daubers), Isodontia (including grass carrier wasps), Palmodes, Prionyx, and Sphex (including the great golden digger wasp and great black wasp).