1988] Deyrup, Cronin, & Kurczewski — Alio chares 269 
tube-like retreat (Fig. 2A). As soon as the wasp moves into the main 
area of the web, the spider runs rapidly out of the back of the 
retreat, usually leaving the web completely. If a narrow crack is 
available, the spider may wedge itself in, and may be able to escape 
from the hunting wasp. The spacing of the cardboard in the labora- 
tory cages provided cracks wide enough to allow even the largest 
wasps complete access to the spiders. Spiders in these cages, when 
approached, leave their webs and hide in one of the cardboard 
cracks or in the web of another spider. Once the spider has taken up 
a position outside its own web, it remains completely motionless, 
even when closely approached by a wasp. The wasps are apparently 
unable to recognize a motionless spider, and on many occasions a 
wasp repeatedly searched the abandoned web, passing within 1-2 
mm of its intended prey lying motionless outside the web. If the 
wasp actually touches a spider, the latter normally rushes away, 
closely pursued by the wasp. Contact with a Filistata appears to 
elicit in the wasp an attack response. If a wasp is captured and 
imprisoned in a vial, it dashes about attempting to escape, but if a 
Filistata has been included in the vial, the wasp stings it on first 
contact, and begins to drag it about the vial while seeking an exit. 
Once a wasp contacts a spider, she attempts to sting it in the 
sternum. The movements of both wasp and spider are so rapid that 
we have not established an exact sequence of events. The wasp 
usually attacks from behind, standing on top of the spider and 
curving her gaster around to the venter of the spider. In some cases 
the spider either turns itself over or is actually flipped over by the 
wasp. We have never seen a frontal confrontation with the spider 
attempting to use its chelicerae to ward off the wasp, though the 
largest Filistata, when cornered, appear to stab with the front legs at 
the approaching wasp. The entire conflict lasts no longer than 2 or 3 
seconds, and terminates abruptly when the wasp succeeds in deliver- 
ing a thrust to the sternum, causing instant paralysis of the spider. 
Unlike most pompilids, A. azureus does not bury or otherwise 
conceal her prey, but rather places it in the spider’s own web. The 
web is strongly built, and its tangling hackled bands of microscopic 
loops remain functional for a long time without maintenance. After 
initial inspection of the prey, during which she may apply her 
mouthparts to the site of the sting, the wasp attempts to relocate the 
web. She may begin at once hauling the spider about by the base of 
