A CLOSE RELATIONSHIP BETWEEN TWO SPIDERS 
(ARACHNIDA, ARANEIDAE): 
CURIMAGUA BAYANO SYNECIOUS 
ON A DIPLURA SPECIES* 
By Fritz Vollrath 
Smithsonian Tropical Research Institute 
P.O. Box 2072, Balboa, Canal Zone, Panama 
Spiders are known to be strictly carnivorous and, moreover, 
often cannibalistic as well. Yet some animals have achieved a status 
of close coexistence with several spiders, notably web spinners. 
Web-building spiders do not change web sites frequently. They are 
rather sedentary (Turnbull, 1964), which makes their webs a suitable 
habitat for associates. Some wasps ( Eumenidae , for example) build 
their mud nests within the webs of the “social” spider Anelosimus 
eximius (Vollrath, in prep.) whose webs also harbor certain moth 
larvae (Robinson, 1977a) and Hemiptera (Vollrath, in prep.). The 
most striking examples of coexistence, however, are the kleptopara- 
sitic spiders of the genus Argyrodes (Theridiidae) that inhabit the 
snares of many web-building spiders (Brignoli, 1966; Robinson 
and Robinson, 1973; Vollrath, 1977). 
In this article I describe some aspects of the biology of another 
spider that lives in close association with a web-building spider. It is 
the only spider known so far that is unable to capture its food but 
has to rely on its host to catch and, even further, to predigest the 
prey. 
CURIMAGUA AND DlPLURA 
Curimagua bayano (Symphytognathidae; Forster and Platnick, 
1977) has only been found riding on the cephalothorax and crawling 
on the webs of Diplura sp. (undescribed species of Mygalomorphae, 
specimen in the American Museum of Natural History) in Panama. 
Although the diplurid host is not uncommon in different localities 
in the monsoon forest at Pipeland Road (Canal Zone), only in the 
Bayano limestone cliffs (the stream banks of the Rio Maje and Rio 
Tigre) did their webs harbor Curimagua. On a recent trip to Iquitos, 
* Manuscript received by the editor January 15, 1979. 
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