82 
Psyche 
[March 
My observations on B. stenebdoma involve a single female seen 
plunging into an open hole in a small draw 1 .5 km SW of Bernardo, 
Socorro Co., New Mexico, at 1000 hours on 2 August 1978. The soil 
in this area was coarse, stony, and hard, with sparse desert 
vegetation, but the draw was sandy and bordered by Croton plants 
which were in bloom and attracting many bees and wasps. Despite 
several hours of intensive collecting in this area by Kevin M. O’Neill 
and myself, we took no other specimens of B. stenebdoma. 
This female was captured as she left the nest, and the nest was 
excavated. Burrow diameter was about 8 mm, and there was no 
obvious mound of soil at the entrance. The burrow was straight and 
oblique, 30 cm long, terminating in a single cell at a vertical depth of 
20 cm. The cell was horizontal, 10 mm in diameter by 20 mm in 
length. It contained 10 paralyzed lacewings, all lying on their sides 
with their heads facing the entrance to the cell. The egg of the wasp 
had been laid on the side of one of the lacewings deep in the cell. The 
egg was elongate and curved, measuring 2.2 mm in length; it was 
Figure 1 . Prey and egg of Bembix stenebdoma. The cell contents have here been 
removed to an artificial cell and the lacewing bearing the egg moved to the top of the 
pile for purposes of photography. 
