176 
Psyche 
[June 
line- Angus event recorder (chart speed of 15.2 cm/min). Total 
observation time varied according to whether the subject reached 
sexual maturity or died at a previous instar. The temporal pattern- 
ing of leg waving from six laboratory-maintained spiders during the 
.antepen- and penultimate instars was also recorded. Protocol was 
whispered into the microphone of a tape recorder. These recording 
instruments were placed on a separate table from the observation 
chambers to minimize the effects of machine vibration. 
Vestigial- winged Drosophila melanogaster were offered as food to 
each spiderling once weekly, and a constant water supply was avail- 
able. The spiderlings were maintained and observed under relatively 
constant temperature (22-26°C) and humidity conditions (55-62% 
RH). 
Results 
Leg waving display in immature S. crassipes consisted of the 
simultaneous raising and lowering of the first and second ipsilateral 
legs. Leg waving was generally performed at a steady and smooth 
rate, and not alternated from side to side during a leg waving bout. 
Spiderlings showed no preference for either the right or left side 
during leg waving. Although leg waving occurred nearly as often 
per 30 min during all instars, no consistent temporal patterning was 
evident until the antepen- and penultimate instars, at which time 
leg waving became increasingly stereotyped and sexually differen- 
tiated. 
Leg waving was observed only five times in the 24 socially iso- 
lated spiderlings. Four of these instances were; limited to those 
spiders having visual access to one another, while only one visually 
isolated spiderling exhibited leg waving. The five observations of 
leg waving occurred in females once each at the second, third, and 
antepenultimate instars, and in males twice during the penultimate 
instar. 
Although leg waving was rarely observed in socially isolated spider- 
lings regardless of age or sex, socially grouped spiderlings of both 
sexes at all the developmental stages studied exhibited leg waving. 
With regard to the frequency of leg waving as a function of age, no 
differences were evident in the average frequency of leg waving/30 
min among the four developmental stages (second instar: 19.7 ± 
9.6 SD; third instar: 21.2 =t 6.3 SD; antepenultimate instar: 
19.8 d= 5.1 SD; penultimate instar: 22.2 ± 6.7 SD). Considering 
