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used to hold and kill prey — are tiny and fused at the bases (see also 
Forester and Platnick, 1977). Moreover, the chelicerae are located 
deep inside the mouthlike basin. Therefore, I consider it unlikely 
that they could be used to hold or tear even the smallest prey, thus 
restricting Curimagua to liquid food. I confined Curimagua to Petri 
dishes (diameter 5 cm) which contained a variety of small arthro- 
pods (Collembola, Coleoptera, Ricinulei) found in Diplura webs, as 
well as dead food items, but never did I find the spiders feeding on 
any of these offerings. Curimagua bayano shares fused chelicerae 
with its congenerics (Forster and Platnick, 1977), some of which 
construct very finely meshed orbicular webs with a diameter of only 
several mm (Eberhard, pers. comm.). The prey of these free-living 
congenerics are unknown. Their nets with a mesh size of approxi- 
mately 125 /I (Patu saladito) may serve to filter for aerial plankton 
such as pollen and fungus spores (Vollrath, in prep.). 
When a Diplura that is carrying Curimagua bayano is fed an 
insect, the Curimagua climbs forward from its resting position on 
the central cephalothorax, over the eyes, and down the mighty 
chelicerae of its host until it reaches the digestive fluids enveloping 
the prey item. The abdomen of the pirating associate visibly swells 
and only a few minutes pass before the Curimagua climbs back onto 
the cephalothorax. Individuals moving about in the silk of the 
retreat are also attracted to a feeding Diplura, perhaps alerted by 
the vibrations generated by the masticating movements of the host. 
Other Associates of Diplura 
Curimagua is not the only associate of Diplura webs. Other 
spiders ( Mysmenopsis ssp.; Platnick and Shadab, 1978) have been 
found by Kraus (1955) in Guatemala, and three species of Mys- 
menopsis (M. dipluroamigo, M. ischnamigo, and M. gamboa) were 
observed by Kirkendall (in prep.) in Panama in the webs of three 
differently sized diplurid spiders. These associates move about in the 
sheet region of the diplurid web, approaching and catching small 
insects that failed to attract the host. Some individuals might also 
move toward a feeding host, but I rarely saw them sharing its prey. 
Most often their approach is detected by the Diplura, which then 
turns around in the retreat, spreading silk with its long spinnerets 
and thus hindering the advance of the would-be pirates. I never 
observed this behavior of Diplura directed toward Curimagua. The 
