1978] Lubin, Eberhard, & Montgomery — Miagrammopes 11 
that, at the end of a sag, when the spider jerks the line up again, 
the prey is “snapped” back upward and accelerated more than the 
silk just above it so that it “runs into” the thread above it. The 
second of these hypotheses is more appealing since 1) it would work 
with non-vertical capture threads whereas the first would not, and 
2) we saw two instances in which a loop clearly formed in the thread 
just above the prey. In any event, the spider is somehow able to 
entangle the prey from a distance by manipulating the capture 
thread. 
Stage III: Immobilization of prey-wrapping 
After manipulating the capture thread to cause one or more sags, 
(a) (b) 
8 
Figure 7. a) Movements of the tip of leg I of a female Miagrammopes simus as 
she sagged the capture thread. Points are locations of the tip of leg I holding the 
capture thread, taken from a video-taped sequence with “frames” 1/60 sec apart. In 
frames 3-5 the tip of the leg remained in the same spot. In frames 9 and 1 1 the tip of 
the leg was not visible; these points are not shown in the figure, b) Movements of a 
prey on the capture thread while the thread is being sagged and jerked back up and 
down, taken from a video-taped sequence (as above). Numbers refer to segments of 
the path of movement of the prey on the line during consecutive 1/60 sec intervals. 
Scale marker represents 10 mm. 
