1965] 
Gardner — Phidippus 
137 
Table I 
The 1964 breeding season for the three species of Phidippus at Reno, Nevada 
Collection dates for:* 
P. coccineus 
P. opifex 
P. apacheanus 
juveniles in pen- 
ultimate instar 
Oct. - June 
? - July 
(Aug.) - Oct. 
adult males 
April - July 
July - Aug. 
Sept. - Oct. | 
adult females: 
unmated 
gravid 
w. egg coccoon 
May 
May - July 
July 
July 
? 
Aug. - Sept. 
Oct. 
Oct., Nov. - ? 
(Dec. - Jan.)** 
^Parentheses indicate that field collection dates are unavailable and dates 
for spiders maintained in the laboratory have been used. 
**Possibly, abnormally early. In the laboratory, warmth and abundance of 
prey during the winter produces anomalies, e.g., penultimate P. coccineus 
juveniles become mature in Dec. -Jan. 
bear only one batch of eggs, such as P. clarus Keyserling of the 
northeastern United States, coccineus females came out of their nests 
to capture the prey that were offered daily. Phidippus clarus remains 
with the egg cocoon continually, and generally dies within a few days 
of the spiderlings’ emergence from the nest. For P. coccineus, the 
median time from oviposition to hatching was 21 days. The young 
remained in the web through a first molt some 16 days later, and 
emerged from the nest 21 days after hatching. These times show 
little variation : for 1 1 batches of spiderlings the range of time from 
egg-laying to emergence from the nest was 37-46 days. 
The spiderlings were self-sufficient when they left the nest. If 
moved to an individual glass vial, almost all spiderlings built a minia- 
ture of the adult sleeping nest within two days. Flightless Drosophila 
placed in the vial are soon captured : for one batch of 24 spiderlings, 
the median catching time was 3.7 min. and all but two of these 
spiderlings had caught their first prey within 60 min. However, it is 
not easy to rear the spiderlings : only 30 of almost 180 young, kept 
in individual vials over wet cotton wicks and fed every two days, 
have survived to date (i.e., approximately five months and four post- 
emergence molts). Most of the losses occurred in the first fortnight 
after leaving the nest ; later deaths generally occurred while the 
spider was molting. 
Courtship 
Method of observation 
Complete mating behavior can be observed by placing the male 
together with a female reared in the laboratory from the penultimate 
instar to maturity, that is, a female known not to have mated pre- 
