Genus Amphasia
Of medium size, elongate-oval, subconvex; labium emarginate; mentum not dentate; elytral margins sinuate at apex; prosternum usually with several setigerous punctures at apex; abdomen punctured over entire surface; protibiae with outer apical angle not prolonged; first metatarsal segment as long as the three following segments combined.
Ampasia interstitialis (Say)
Elongate-oval, robust; head, pronotum, antennae, and legs reddish yellow; elytra, meso-, and metathorax piceous; remainder of undersurface reddish yellow. Pronotum transverse; base and apex subequal in width; sides and apex broadly margined; basal impressions shallow, densely punctate; posterior angles broadly rouded. Elytra deeply striate; intervals convex, coarsely and densely punctate. Length 9.5 - 10 mm.