370 
Psyche 
[September 
Fig. 4. Construction of the pupal line. Activities illustrated are swinging 
(a), cutting (b ) , tapping (c), trimming (d), and turning around ( e ). 
wards, leaving a slime trail extending all the way to the end of the 
new silk. Larvae left overnight on a new surface often constructed 
long dendritic networks of silk trails, each with a slime trail running 
down the middle. 
The larvae were apparently able to perceive vibrations in their 
sheets, but either fled from or did not respond to the struggles of 
animals such as sminthurid collembolans caught in the sheet. They 
usually appeared to sense the presence of another larva before contact 
was made, and often moved away as another approached, but occa- 
sionally when they met head to head, larvae fought. Their heads 
locked, and they swung from side to side in wide arcs, sometimes 
quite violently. After a few swings they disengaged, and one or 
both backed away. 
Construction of the pupal line 
Before pupating, the larvae always suspended themselves on a 
line under or near the surface where they had been feeding. The 
process of construction of this line was nearly identical in each of 
four cases observed in captivity. 
