1969] 
Robinson — Predatory Behavior 
49 
site is another matter. In the case of Nephila it does not immediately 
free the spider to make new attacks. After such wrapping Nephila 
carries the prey to the hub and never leaves it in situ . Post immobili- 
zation wrapping at the capture site, by Nephila, must, therefore, 
have other functions. It certainly reinforces the immobilization 
achieved by the biting attack, as must post immobilization wrapping 
at the feeding site. There are, however, good grounds for assuming 
that this is not the primary function. Capture site wrapping, type i, 
can be elicited by manipulating the prey, experimentally, in such a 
way that it cannot be pulled from the web by the spider. It is then 
a response to a failure of the prey removal process (Robinson & 
Mirick, in prep.). It seems reasonable to suppose that such capture 
site wrapping functions primarily to allow the spider to cut the prey 
from the web without losing it. The prey package resulting from the 
wrapping process is compact partially disentangled from the viscid 
spiral, and securely attached to a radial web member. Eberhard 
(1967, p. 177) reported an instance in which a diguetid spider 
anchored a large prey to the web (with silk) before releasing it from 
the chelicerae and removing it from the web. This seems to be a 
functionally similar process to the capture site wrapping, type 1, by 
Nephila. 
When wrapping occurs at the capture site, after the prey has been 
freed from the web by pulling (type 2), the function seems to be to 
facilitate transportation to the hub. After such wrapping the prey 
is carried suspended from leg IV, and not in the jaws. Both 
Argiope argentata and Araneus diadematus carry prey from below 
the hub, and above a certain weight range, on silk rather than in 
the jaws (Robinson 1969, Peters 1933b). In these spiders, and 
Argiope savignyi , A. florida and Eriophora sp., this carrying tech- 
nique occurs after post immobilization wrapping at the capture site, 
type 1. All the spiders that we have studied, i.e., the Argiope spp., 
Nephila clavipes, and Eriophora sp., build webs which are inclined 
to the perpendicular to a greater or lesser extent. The spider rests 
on the undersurface of the web and almost always carries its prey 
along that surface, or close to it. The lower portion of the web 
(below the hub) is normally greater in area than the upper portion. 
When carrying prey from the lower portion the spider is walking 
against the slope. This means that prey carried in the jaws, and 
therefore partially beneath the spider, are in a position which poten- 
tially favors entanglement during transportation. Prey carried be- 
neath the spider, on silk, hang away from the web and are thus 
much less likely to become entangled during transportation. The 
