BAG-WORMS ON ORANGE. 145 



basket is differently constructed to suit its surroundings; on oak it is 

 usually formed of bits of rounded twigs, placed crosswise alter the fash 

 ion of a log cabin ; on trees with dense foliage like the Orange it is oftener 

 fashioned with leaf material. In all cases it is thickly lined and firmly 

 bound together with strong, grayish-white silk, and is too tough to be 

 torn asunder with the fingers. Before the larva becomes a pupa the 

 bag is suspended by a band of silk to a twig or branch. 



The winged male escapes from the sack leaving the pupa shell pro- 

 truding. It is a rather thick-bodied moth of dark brown color. The 

 abdomen is very long, slender, and tapering to the point, which is 

 armed with a pair of shell like claspers, and these conceal the point of 

 the intromittent male organ. These parts are very elastic and extensile, 

 and enable the male to reach deeply into the sack of the female, in the 

 act of coupling. The fore-wings of the male are rather long and nar- 

 row; they are slightly paler than the body, and are marked with a 

 short oblique line, devoid of feathers, and situated just beyond the 

 middle of the wing. The hind wings are short and angular. 



The female is without wings or legs, and is, in fact, hardly more than 

 a living egg-sack. When fully mature the pupa splits at the anterior 

 end, and the body of the female protrudes. Without entirely leaving 

 the pupa shell, but dragging it after her, she works her way to the 

 mouth of the basket, where she awaits the visit of the male, having her 

 head at the outlet. 



In what precise manner the act of fertilization takes place is not well 

 understood,* but as soon as it is accomplished, the female pushes her- 

 self backwards to the farther end of the basket, and, her hinder ex- 

 tremity being still within the pupa shell, she proceeds to fill it nearly 

 full of pearly, cream-colored eggs, packed in silk. The vacant space at 

 the end is then filled with a tangle of floss silk, mingled with feather 

 scales, which the mother plucks from her own body. When finally 

 her body is entirely withdrawn from the pupa shell the lips of the 

 f shaped slit at the end snap together, entirely closing the exit. 



The female continues to work her way slowly outward, weaving as 

 she goes a tangle of silk, mingled with scales stripped from her own 

 body. Having filled the entire space within the basket, and lest she 

 should imperil the safety of her young by remaining in the case to die, 

 the mother completes the sacrifice by dropping from its mouth. Her 

 exhausted body, shorn of its downy covering, falls to the ground, where, 

 naked and defenceless, it becomes a ready prey to ants and other 

 prowlers. 



How wonderful an example is here shown of the power of the mater- 

 nal instinct, which can thus overpower the instinct of self-preservation 

 in an unreasoning insect, and compel her to yield to her offspring, 

 unborn and unseen, a secure retreat, which otherwise in life she never 

 leaves, and from which she could not be torn except piecemeal. 



The eggs of the Bag- worm hatch in September. The young larvae 



* See Appendix III. 

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