26 
Psyche 
[March-June 
Figure 2. Body weight of four FG and seven SG littermate males in 
set I of Araneus diadematus, hatched in the laboratory from one cocoon 
on February 23, 1972. Dashed line: weekly mean body weights of the FG 
males. Dotted line: weekly mean body weights of the SG males. Numerals 
followed by an arrow indicate the number of animals molting for the last 
time during a week. Numerals surmounted on black circles indicate the 
number of animals dying during a week. The FG males reached their 
maximum weight the 13th week of post-hatching, the SG males reached 
their maximum the 29th week of post-hatching. Note that the SG animals 
need twice as much time to mature as the FG. 
(Turnbull, 1962). We may assume that the adult males, no longer 
able to build a web, do not neeed food to fulfill their mating role. 
Four males in this study continued to spin webs until they died; 
they built webs for a few days after the last molt was recorded, then 
stopped building for three or four weeks and generally built a final 
web six or seven days before death. These facts suggest that these 
four males were not able to go through an additional molt to com- 
plete their development. Also, these males presented enlarged palps 
only after the last molt recorded which is another confirmation of 
thir inability to complete their development. 
During the web building period the males are distinct from the 
females only between the two last molts (about 3 weeks). This 
explains why few studies have been made of the males either outdoors 
or in the laboratory. 
