SODTH AFRICAN BAGWORMS. 64] 



female at the posterior end, filling this part of the case up 

 to the third or even second abdominal segment. The 

 chrysalis containing the egg-mass is encased in a bag of 

 strong white silk (the cocoon or inner bag) Avhich is stretched 

 as a central tube in the bagworm-case, attached to both 

 the anterior and posterior ends. 



Development. — External changes : As the egg becomes 

 older it changes from the fresh cream colour to a dirty 

 yellowish white, and later to greyish white, ultimately to 

 dark grey with a black spot indicating the head and 

 thorax of the developing larva. The incubation period is 

 from sixty to sixty-five days. 



(4) The Larva. 

 First Instar. 



Length upon emergence 1*9 mm.; ground colour cartridge- 

 buff ^ (XXX); head jet black; dorsal thoracic shields, plate 

 on eighth abdominal segment and anal plate Van Dyke brown 

 (XXVIII) ; the third thoracic shield divided by a median 

 stripe of the ground colour. Prespiracular plates of second 

 and third thoracic segments concolorous with dorsal shields, 

 other setiferous plates drab (XLVI). Thoracic legs snuff - 

 brown (XXIX) ; leg-plates of abdominal and anal prologs 

 buffy brown (XL) ; claws of prologs bistre (XXIX). 



The larva (text-fig. 1, a) is more or less cylindrical, very 

 slightly flattened dorso-ventrally. While in most cater- 

 pillars the head is very large upon hatching and the body 

 tapers from the neck caudad, we find here that the width 

 of the head is surpassed by that of the thorax, which is 

 massive, especially the third thoracic segment, and from 

 the posterior edge of it the abdomen tapers gradually 

 down to the tail, like a cone. The great strength of the 

 third thoracic segment is probably necessitated by the 



' Tbe colours mentioned are those of Ridgway's ' Colour Standards 

 and Nomenclature,' edition 1912 ; the numbers refer to the plates in 

 this publication. 



