322 
Psyche 
[Vol. 89 
Materials and Methods 
Procedure. Nesting sites and mud nests of three species of sphecid 
wasp were observed during the summer of 1980. Three groups of 
spiders were collected. These were: (a) active spiders within 2 meters 
of wasp nesting sites, (b) active spiders on or next to mud-dauber 
nests, and (c) paralyzed spiders from inside 110 old nests. Spiders 
were identified and their total body lengths measured. No attempt 
was made to census every spider at each site, as this would have 
proven impossible for genera such as Tidarren and Filistata which 
were numerous, mobile and often reclusive. In addition, encounters 
between spiders and wasps were observed and recorded. 
The Wasps. Sceliphron caementarium (Drury) (Sphecinae: Sce- 
liphrini) constructs individual cells of mud collected at the edges of 
ponds and streams. The nests are provisioned primarily with Ara- 
neidae, Thomisidae and Salticidae (Muma and Jeffers, 1945) and 
then sealed off with mud. Groups of contiguous cells are often 
covered by additional layers of mud and may appear as oval or 
oblong masses of up to 30 cells (see Muma and Jeffers, 1945 for 
plates of relevant mud-daubers and their nests). Trypoxylon poli- 
tum Say (Larrinae: Trypoxylini) builds long, tubular nests from 
mud gathered at sites similar to those frequented by Sceliphron. 
The “pipe organ” nests usually contain between 3 and 5 cells, each 
provisioned with Araneidae of the genera Neoscona or Eustala 
(Muma and Jeffers, 1945; H. J. Brockmann, pers. comm.). Rather 
than constructing its own nest, the blue mud-dauber, Chalybion 
californicum (Saussure) (Sphecinae: Sceliphrini) either modifies and 
seals existing old cells of Sceliphron and Trypoxylon or cleans out 
and reprovisions recently completed cells. Dry mud from nearby 
nests is softened by mixing with water stored in the wasp’s crop. The 
wet mud is then manipulated and used for sealing nests. Chalybion 
specializes in hunting small Theridiidae and Araneidae (Muma and 
Jeffers, 1945). 
The Study Sites. Three sites in Alachua County, Florida were 
selected. Two were located in the Paynes Prairie State Preserve and 
were designated Boat House (BH) and Garage (G). Both sites had 
females of all three species actively building and provisioning nests. 
The boat house site had a 10 m X 25 m X 1 m high shaded crawl 
space with an unfinished pine ceiling, dirt floor and open sides. The 
