128 
Psyche 
[June-September 
In order to see larval behavior inside the case, I installed windows 
(Figure 3). A rectangle was cut from one side of each of several 
cases; a piece of clear lightweight plastic was then glued over each 
hole. I observed turning movements, feeding, excretion, molting, 
and pupation through these windows. 
To turn around inside the case, the larva withdraws until its 
posterior end reaches the constriction leading to the opening at the 
other end, then turns its head to one side and doubles back on itself. 
When its head has moved past the midpoint of the case, it 
straightens its posterior end to complete the turn. 
Upon encountering food (dead insects, animal hair), the larva 
chops it into pieces and pulls it into its case. Feeding takes place 
only within the case. Larvae reared for study were fed dead mosqui¬ 
toes and my hair (Figure 4). The larva never protrudes its posterior 
end outside. It defecates inside the case, then turns around inside 
and pushes the droppings out with its head. 
Molting also takes place within the case. The larva retreats into its 
case and does not emerge again for about 24 hours. After ecdysis, it 
turns around and pushes the shed skin and head capsule out, using 
its head. 
Locomotion 
Phereoeca larvae have two main types of locomotion; one con¬ 
cerned with movement about the habitat while pulling the case 
behind, the other with movements inside the case. 
The prolegs of Phereoeca are somewhat reduced, but crochets can 
be seen under a microscope. That the tenth segment prolegs are used 
to grip the case when moving was demonstrated by several simple 
experiments. I cut a case in half transversely so that the larva s head 
and thorax stuck out of the neck and its posterior end protruded 
from the large cut end (Figure 5). When it tried to walk and pull its 
case, the larva went nowhere because it held onto the table with its 
tenth segment prolegs. When I positioned the loose half of the case 
against the larval half so that the cut edges came together, the larva 
held onto the loose half with its tenth segment prolegs, and walked 
around pulling both halves of the case behind. I then covered the 
tenth segment prolegs with Elmer’s Glue-all® and the larva was no 
longer able to pull the loose half of the case behind it. However, it 
