PSYCHE 
Vol. 93 
1986 
Nos. 3-4 
THE CHOICE OF WEB-MONITORING SITES BY A GREEN 
MIAG RAM MOPES SPECIES (ARANEAE: ULOBORIDAE)* 
By Brent D. Opell 
Department of Biology 
Virginia Polytechnic Institute and State University 
Blacksburg, Virginia 24061 
Introduction 
The varied and effective predatory strategies of spiders have 
drawn more attention than have their antipredator adaptations to 
threats from birds, wasps, damselflies, and other spiders (Bristowe 
1941, Dorris 1970, Blanke 1972, Jackson & Blest 1982a, b). As the 
majority of their predators are visual hunters, it is not surprising 
that many spiders employ either protective resemblance or eucrypsis 
(as defined by Robinson 1969a) to escape detection. In general, 
protective resemblance seems to be more common among spiders 
that use a capture web and eucrypsis among hunting spiders that 
employ sit-and-wait tactics. Protective resemblance usually involves 
anatomical modification and is frequently enhanced by postural 
specializations (Robinson 1969b). Both of these antipredator adap- 
tations are often enhanced by a spider’s color. 
In order for protective resemblance and eucrypsis to be effective, 
animals employing these strategies should select a background 
whose color or texture closely matches their own. Such background 
selection has been demonstrated for adult moths (Kettlewell 1955, 
Sargent 1966, 1984; Sargent & Keiper 1969, Malcom & Hanks 
1973), butterfly pupae (West & Hazel 1979), and grasshoppers 
(Giles 1982). Several studies have demonstrated the protective 
* Manuscript received by the editor May 16, 1986 
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