248 
Psyche 
[June 
cursorily or not at all during intermittent searches for weeks prior 
were searched very thoroughly on one day when at least three spiders 
were captured there. About two weeks later, hunting intensity had 
returned to the level previous to the burst of captures. 
The wasps may also establish hunting routes. One individual 
visited a series of four windows in the same order four times, each 
time after depositing a new spider in her nest. She caught all the 
spiders on the third and fourth windows, and the later visits to the 
first two windows were very brief. 
When a wasp encountered a silken retreat with a spider in it she 
immediately pulled and tore at the silk in the side of the retreat 
with her mandibles. After a few tugs by the wasp, the spider 
usually left the retreat at the end farthest from the wasp and de- 
scended on a thread. Spiders usually remained inside vertical retreats 
longer when the wasp was attacking from below, leaving the top 
end hesitantly. One spider moved to the bottom of the retreat where 
a wasp was pulling, moved back up to the top end, and, when the 
wasp moved to the top along with it, dropped out the bottom. 
The wasps pursued the spiders as they struggled out of their 
retreats and as they fell. Several times a wasp captured a spider 
just as it fell from the retreat and stung it as she flew away. On 
three occasions the spider fell to a windowsill and the wasp attacked 
it there. In each case the wasp grasped the spider with her mandibles 
and front pair of legs and curled her abdomen forward beneath her 
body and stung it. On one occasion a wasp stung a spider four 
times, the last three times on the ventral side of its cephalothorax. 
Several other times a wasp stung a spider- as she flew, then landed 
and stung it at least once more. 
On two occasions a spider dropped out of its retreat and hung on 
a line some distance below (once after it hit the windowsill and 
crawled off that). In one of these cases, the wasp captured the 
spider as it hung, and bent her abdomen forward and stung it as she 
flew away. In the second case, she landed on the windowsill after 
seizing the spider and bent her abdomen forward and sideways to 
sting it. 
Usually a wasp paused for several seconds after stinging a spider, 
and on at least four occasions, the wasp’s mouth was pressed against 
the mouth region of the spider during this pause. On one occasion 
the spider was rotated so that its mouth region was next to that of 
the wasp. The wasps may have been ingesting fluids from their 
victims’ mouths during these pauses. 
