206 
Psyche 
[June 
L. punctulata, most of our L. rabida were males, which may tend 
to wander more and to interact agonistically at trio density, thereby 
spending less time resting at an elevated foliage site. This is only 
a guess.) 
Orientation preferences. — Leaf slope preferences on the arti- 
ficial foliage were not consistent among and even within the 
species, some spiders being located most often on a 60° slope, 
others most often on a vertical surface (Table II). These data, 
as well as the readiness of control spiders to rest on both 60° and 
vertical broad surfaces, suggest that there possibly is no prefer- 
ence for oblique vs. vertical leaves as resting sites in these lycosids. 
There was a definite preference, however, for upper- rather 
than undersurfaces of sloping (60°) leaves (Table II). Similarly, 
control spiders on the broad surfaces rarely rested while holding 
onto the undersurface of a 60° cardboard wall. An inverted posi- 
tion likely provides less secure “footholds” for resting or for 
chasing prey in these webless spiders. It also is less suitable for 
the critical act of pouncing on the prey, since the spider would 
have gravity working against it. 
Most aerial web-weaving spiders orient in a face-down position 
while resting in their webs (Eberhard, 1967). Orientation prefer- 
ences also were shown by our lycosids on sloping or vertical sur- 
faces, the spider most often adopting a vertical position. As with 
web weavers, a vertical position possibly yields optimum “claw- 
holds” with the least amount of energy expenditure while waiting 
for prey. On artificial foliage, the most common resting position 
for lycosids, like that of web weavers, was facing directly down- 
ward. On a broad surface, the vertical orientation was again 
predominant, although the lycosids here faced up as often as 
down. Either way, equivalent input from the proprioceptors of 
the right and left sides is achieved, which may be the primary 
determinant of this orientation. 
Visual and mechanical prey-detection by wandering spiders 
resting in the herbaceous stratum probably are enhanced by ver- 
tical orientation on stems or grass blades, since this aims the spider 
in one of the two main directions from which crawling prey are 
most likely to approach. Kuenzler (1958) noted that crawling 
prey are the primary food of lycosids. 
A preferred vertical orientation on grasses and other plants 
may have influenced selection for the bold stripes running length- 
