APPENDIX III. 



THE COITION OF BAG WORMS. 



The following is an extract from an account of certain Australian Bag- worms, by 

 William W. Saunders, as read before the Entomological Society of London, February 

 1, 1847.* 



"August 30. On this day I first observed a yellowish white substance protruding at 

 the lower end of the largest cases, which upon close examination proved to be a por- 

 tion of the females in the imago state, one-third of their bodies being exposed. About 

 an hour afterward, examining the cases again, I found the females had receded, and in 

 opening a case the female moth became evident within, and thus they emerge and 

 recede as occasion may require.. The female is a lo,rge apterous moth, with a very 

 little of the ordinary appearance of an insect of the moth kind. The length is about 

 If inches, diameter full half an inch, color yellowish white, fawn, or buff; head and 

 three first segments of the body naked and glossy on the upper part; feet very short. 

 Antennae none, or at least not visible to the unassisted eye ; anal segment of the 

 body clothed all round with a dense covering of silky down [42] of a deeper color than 

 the rest of the body ; ovipositor well developed. 



" September 5. Examined some of the females, no males having yet appeared. Two 

 or three were dead ; one nearly so, having deposited a great number of ova in the 

 pupa case, which were enveloped in a short silky material. When the female has de- 

 posited all her ova, she is literally nothing but thin skin, which soon desiccates, leav- 

 ing room for the young larvae to pass. I have examined other species of Oiketicus, and 

 find all the females are apterous. 



"September 20. A male imago appeared this morning. It had been in active opera- 

 tion a good while, as evinced by its wings, being much broken at the tips and other- 

 wise much abraded. It is an insect of very peculiar construction, and seems to have 

 some affinity with Zeuzera. It has the extraordinary power of extending the abdo- 

 men to 2 inches in length, and of turning and twisting it in all directions. When in 

 this state it has alternate rings of black and yellow, with a curious appendage at the 

 extremity. The male appears very eager to accomplish the grand object of nature, 

 namely, the continuation of its species, as its existence appears to be of short dura- 

 tion. The large fat or rather distended females have not room to turn their bodies 

 so as to present the generative organs conviently to the male, consequently the immense 

 development of the abdomen in the males is of the greatest importance ; but it appears 

 very extraordinary that the head of the female should be inverted, when it is known 

 that she never emerges from the case unless by accidentally falling therefrom, which 

 position obliges the male when in the act of coition to stretch his abdomen all along 

 the side of the female full If inches. This peculiarity appears to me to be the design 

 of the all-wise Creator, in order to afford a secure place for the defenseless larvae, viz, 

 that of the pupa-case of their parent, from which they emerge after the disappearance 

 of their mother's body, and immediately form themselves silken cases covered with 

 small pieces of anything they can procure, arranged in every respect like the larger 

 ones." 



* Remarks on the habits and economy of a species of OiTceiicua found on shrubs in 

 the vicinity of Sydney, N. S. W., by W. W. Saunders, esq., F. L. S., &c. Drawn up 

 from notes furnished by W. Stephenson, esq. Transactions of the Entomological So- 

 ciety of London, Vol. V. 1847-1849. pp. 40-33. 



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