132 
Psyche 
[June-September 
this pattern “6” moved into a nearby corner. The greatest minimum 
distance moved from one day to the next was 228 cm (partly hori¬ 
zontal, partly vertical). 
Among eighteen individuals studied in detail, the average distance 
travelled per 24 hour period was 42.4 cm (range: 13.7-108.7 cm). 
Nine of these individuals pupated during the study; in each case, 
pupation was preceded by a horizontal wandering phase of 0.5-2.5 
days and a period of vertical movement lasting 0.5-2 days. All nine 
larvae attached their cases to the wall at heights from 64 cm to 244 
cm, and prepared for pupation. 
Pupation 
When a larva approaches pupation, it usually walks up a vertical 
surface and attaches its case firmly with silk at both ends. It then 
modifies one end of the case by cutting a short slit along both edges 
of that end. An end thus modified becomes much flatter and is no 
longer pulled shut by the larva. It acts as a valve; very difficult to 
enter but easy for the adult to exit through at eclosion. 
With its head, the larva next pushes all remaining food and other 
debris out of the case. A day or two later, it molts to a pupa, pushing 
the last larval skin and head capsule into the unmodified end of the 
case (Figure 10). 
Of 73 abandoned pupal cases examined, the average height from 
the ground was 87.7 cm (range: 0-214 cm). There was no relation¬ 
ship between the height from the ground at pupation and either case 
size or sex. Of these, 63 cases were attached vertically, 59 (of the 63) 
with the head down, and 56 (of the 73) with the ventral side of the 
pupa towards the wall. 
Pupal cases are easily distinguished from cases of resting larvae. 
The larval case is held very loosely to the wall with several almost 
invisible silk strands at the upper end; the pupal case is held firmly 
by a great deal of silk at both ends. After eclosion, the empty pupal 
skin projects from one end (Figure 11). Most cases seen on walls are 
actually abandoned pupal cases, but often the pupal skin has been 
eaten flush with the case by other Phereoeca larvae, making it d ;f fi- 
cult to tell that a case is no longer occupied. 
Based on 22 reared individuals, the pupal period averages 15.6 
days (range: 11-23 days). The entire cycle from egg to adult averages 
74.2 days (range: 62-86 days). Among those reared, males matured 
before females and outnumbered them 19:3. 
