1975] 
A spey — Schizocosa 
177 
leg waving las a function of sex, antepen- and penultimate males 
exhibited higher average frequencies of leg waving/30 min (27.2 
db 7.0 SD) than females (12.4 ± 4.0 SD) ( Mann- Whitney 
IJ = 18, p < 0.02). 
Of the 10 males and 10 females collected from the natural habitat 
and grouped separately by sex, nine males and four females reached 
sexual maturity. Cannibalism among these spiders was directly ob- 
served on two occasions ; the remaining deaths may have been due 
to other causes. In the two groups of 10 laboratory-maintained 
juveniles, two individuals from each group reached the fourth instar. 
Among these spiders cannibalism was also directly observed on two 
occasions. 
Among socially grouped antepen- and penulatimate males, bouts 
of leg waving lasted (an average of 7.3 ±2.1 (SD) sec, and con- 
sisted of the legs being waved 3-27 times (x ± SD: 16.0 zb 4.7) 
in succession at a rate of approximately 2 waves/ sec. With in- 
creasing age, film analysis revealed that the foreleg was lifted higher 
off the substratum (20-25° in the second and third instars) until 
an arc 40-50° relative to the substratum was reached in the: antepen- 
and penultimate instars. The second ipsilateral leg that accompanied 
the foreleg during leg waving was lifted only 5-25 0 relative to the 
substratum. The legs were raised and lowered almost simultaneously, 
with the foreleg occasionally leading. 
Among socially grouped antepen- and penultimate females, bouts 
of leg waving lasted an average of 4.1 zb 2.0 sec, and consisted of 
the legs being waved 1-10 times (x iff SD: 3.0 db 2.2) in suc- 
cession at a rate of approximately 1 wave/sec. Although females 
exhibited leg waving more slowly and less frequently than males, 
the behavioral topology of leg waving was indistinguishable between 
the sexes. Bouts of leg waving alternated with variable periods of 
immobility or locomotion, and depended on the behavior of con- 
specifics. 
The circumstances under which leg waving occurred did not seem 
to change with age. A spiderling initiated leg waving in response 
to a darting front approach by a conspecific when it approached to 
within two or three body lengths. In response to one or several 
bouts of leg waving, the approaching spider turned away and/or 
retreated. On the four occasions when cannibalism was observed, 
the cannibalized spiderling was approached from the posterior; leg 
waving was not observed to occur in response to these posterior ap- 
proaches. 
