SOUTH AFRICAN BAGWORMS. 653 



anal plate, anal legplates, dorsal setiferous plates on abd. 8 

 and 9, as also the pattern on thoracic shields, Verona brown 

 (XXIX), pattern on head cinnamon (XXIX). The structure 

 and arrangement of sette and hooks on prologs have not 

 changed. The thoracic legs have become comparatively 

 shorter. The entire larva now appears as if re-modelled 

 without growth within the old skin. Width of head-case 

 of female '3*65 mm., that of male 3 mm. 



Here we find the remarkable occurrence that after moulting 

 the larva is actually smaller than in the preceding instar and 

 during this instar no food is taken, no growth takes place, 

 and there appears to be an actual shrinkage. As the larva 

 does not expose itself to the outside air and light, it does not 

 acquire its full coloration as in the previour instars, but remains 

 in the pale state characteristic of a newly moulted larva. 

 The actual length of this stage has not been ascertained, for 

 if the larva be disturbed and the bag opened for examination, 

 it immediately proceeds to repair the damage. As the tax on 

 the spinning glands is already fairly heavy, having to spin 

 the cocoon, the extra effort of repairing the bag from day to 

 day (and frequent examination would be necessary) would so 

 weaken the larva that it would probably succumb before 

 pupating, especially when we consider that no food is taken 

 to replace the wasted energy. 



(5) Habits of the Larva. 



The habits of the larva of Acanthopsyche junodi (in 

 common with many other Psych ida)) are abnormal in many 

 ways, and different from those of the great majority of cater- 

 pillars. These peculiarities in behaviour are the result mainly 

 of two factors. The first of these, and the principal one, 

 acting during the earlier part of the life of the insect, is that 

 the distribution of the species is not allotted to the parent 

 moth, but that this responsibility has fallen on the young 

 caterpillar. The second factor is the necessity on the part of 

 the defenceless larva for concealment and protection against 

 predaceous and parasitic enemies. 



