Yeah, adult Dubias are a bit too big for a big White's Treefrog. A smaller individual definitely couldn't eat one. They're good food for African bullfrogs and stuff, but even my toads at a bit over 4 inches have a bit of trouble eating adult Dubias. Turkestans are around 1.2 inches long as adults, compared to dubia's 1.8.
Males turkestans can FLY however. Now I remember another reason I went with Dubias.