W. H. Hudson,
The Naturalist in La Plata
“ Now, in summer, to a dry spot of ground like this, comes a small wasp, scarcely longer than a blue-bottle fly, body and wings of a deep shining purplish blue colour, with only a white mark like a collar on the thorax. It flirts its blue wings, hurrying about here and there, and is extremely active, and of a slender graceful figure--the type of an assassin. It visits and explores every crack and hole in the ground, and, if you watch it attentively, you will at length see it, on arriving at a hole, give a little start backwards. It knows that a spider lies concealed within. ”
