246 
Psyche 
[September 
Molting to the adult instar occurred during early June, and ob- 
servations were made during late June and early July. Spiders were 
housed separately and visually isolated from each other. They were 
fed mealworms (larvae of Tenebrio rnolitor ) weekly and had a 
constant water supply. 
Virgin spiders were paired in arenas for observation under fairly 
constant temperature (23-25°C) and humidity (60-65% RH) con- 
ditions. After observing one pair in a preliminary trial, I filmed 
portions of copulation in a second pair. The palpal insertion patterns 
of five other pairs were recorded for later analysis. 
Results 
Copulatory behavior was similar in all seven pairs of S. avida 
observed. Throughout most of copulation, each palp was inserted 
repeatedly a number of times prior to a shift to the opposite palp. 
The length of such series showed the same pattern of variation in 
nearly all cases : few insertions per series at the beginning, increasing 
shortly thereafter to a maximum number of insertions per series, 
then a gradual decrease, eventually ending with a minimal number 
of palpal insertions. (In one male, insertions of the left palp began 
at the maximum series length; i.e., several “introductory” series of 
relatively short length were not shown by this male’s left palp, al- 
though they did occur in the right palp.) 
In the five recorded matings, each palp was inserted an average of 
158 times, for a mean total of 316 insertions per copulation. These 
copulations lasted 2.8 ± 1.63 (SD) hours. Other data are sum- 
marized in Table I. 
Table I. Palpal insertions during copulation in five pairs of Schizocosa 
avida. 
Total no. 
Total no. 
Insertions per series 
Pair no. 
of series 
of insertions 
Mean ± SD 
Range 
1 
21 
241 
11.5 ± 14.7 
2-60 
2 
11 
254 
23.1 ± 9.4 
4-35 
3 
31 
213 
6.9 ± 5.0 
1-21 
4 
34 
371 
10.9 ± 10.6 
1-48 
5 
37 
501 
13.5 ± 10.4 
1-39 
Mean 
26.8 
316.0 
13.2 ± 15.1 
