22 
Psyche 
[March 
Table 1 . Argiope trifasciata residency on communal tangles and associated weather 
conditions during May, 1975. S = sunny, PC = partly cloudy, C = cloudy, 
X = presence, Y = dispersal on same day as emergence. Dispersal occurred 
on last day spiderlings were present. 
May 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 
Weather S SPCS SCCCS S S S SPCPCS 
Egg sac 
number 
5 
6 
11 
12 
13 
14 
15 
16 
17 
18 
19 
20 
21 
22 
23 
25 
26 
27 
29 
30 
31 
32 
33 
34 
X X X X X X 
X X X X X X X 
X X X X X X X 
X X X X X X 
X X X X X X X 
X X X X X X X 
X X X X X X 
X X X X X X 
XXX 
X X 
X X 
X 
X X 
X X 
X X 
X 
X 
X 
X 
X X 
Y 
X X X X 
X X 
X X 
X X X X 
Y 
XXX 
XXX 
XXX 
XXX 
X X 
X X 
X X 
observed and there appeared to be four to six lines, but the exact 
number was not determined. Spiderlings also dispersed directly 
from silk threads. They dropped on a dragline, cut it and while 
suspended and holding this thread by leg pairs I and II, let out 
ballooning silk as before, until they became airborne. 
Spiderlings, as a rule, became airborne during relatively calm 
periods with a preferred windspeed for dispersal of approximately 
0.5 m/sec. (Figure 6). During gusty periods spiderlings either did 
not exhibit tip-toe postures at all or if in that posture, returned to 
