250 
Psyche 
[September-December 
Table 1. Time (min) that six Phidippus johnsoni males remained 
in contact with empty nests, during 15 min tests. See 
text for further details. 
Male 
1 2 3 4 5 6 Mean 
Type Phidippus johnsoni 15 7 3 3 2 11 6.83 
of 
Nest Herpyllus hesperolus 1 0.5 0.5 0.25 0.5 12 2.46 
accounting for the two longer residences at gnaphosid nests (Table 
1). Inside nests, the spiders alternately groomed, walked about, 
and remained inactive. 
Evidently, P. johnsoni males discriminate empty nests built 
by conspecific females from those built by H. hesperolus. Upon 
encountering gnaphosid nests, they did not court, and usually 
they remained only briefly. 
Discussion 
There is little information available concerning the preda- 
tors of P. johnsoni. Pompilid wasps are known to take other 
Phidippus species as larval food (Dorris, 1970; Kaston, 1948; 
Kurczewski and Kurczewski, 1968; Muma and Jeffers, 1945). 
Once an acroserid fly pupated from a P. johnsoni I collected, 
and acroserids are know to parasitize other Phidippus (Evert 
Schlinger, personal communication). No doubt there are many 
predators of P. johnsoni for which there are simply no published 
reports. Reports of the stomach contents of vertebrates are gen- 
erally of little use in determining the predators of particular spider 
species or groups, since the spiders are not identified. 
Almost universally, P. johnsoni males have bright red abdo- 
mens. Although the abdomens of immatures and adult females 
may be dully marked, in many cases they are bright red, orange, 
or gold. In the laboratory and at exposed locations in the field, 
such as on the surface of rocks, these spiders tend to be rather 
conspicuous. There is no evidence that their coloration is apo- 
sematic, although information concerning this is limited. They 
