i86 



Marvels of Insect Life. 



extent possible, the gum is drawn out into a thread of gossamer, which hardens on 

 exposure to the air. and becomes stiff enough to support the egg, which she attaches 

 to its extremity. In so doing, she is doubtless taking precautions against her eggs 

 being eaten by some other Insect, it may be against the grubs of her own kind, 

 for they are all of a voracious character and are not free from the imputation of 

 cannibalism. It has been noted that, where the eggs are sufficiently close together, 

 the first hatched-out grub will cling to its egg-shell and watch for the emergence of 

 its brothers and sisters, catching and eating them as they appear. In the ordinary 

 way the grub crawls down the hair-like stalk of the egg, and finds itself quite close 

 to a flock of green-fly. 



The grub is, roughly speaking, not unlike the lady-bird grub in shape, with 

 six active legs and a somewhat flattened body. Its jaws are so constructed that when 

 not in use they may appear to be four in number, but for practical purposes the two 



parts on each side of the mouth 

 unite to form a sharp-pointed 

 tube. The grub impales a succu- 

 lent green-fly between the points 

 of its jaws and sucks, when the 

 whole of the green-fly's contents 

 are drawn into the mouth through 

 these tubes and the empty skin 

 is cast aside. These jaws are hard 

 worked, for the life of the grub is 

 passed in a continuous picking up 

 of green-fly, emptying them, and 

 casting away the empty skins. 

 With this constant supply of food, 

 our grub increases in size rapidly, 

 and twice it has to cast its skin to 

 get one allowing of greater expan- 

 sion, until, in less than a month from 

 its emergence from the egg, it 

 reaches the limit of its growth, 

 and sets about arranging for its future state. It seeks a suitable crevice, 

 and there fabricates a silken ball or cocoon just large enough to contain itself. In 

 this it lies without change all through the winter, and not until the spring does it 

 cast off its last grub-skin and enter upon the chrysalis stage. The marvel is that 

 in the confined space it should be able to get free from its old integuments. As it 

 is, the chrysalis is packed up in what looks like a very uncomfortable position, and 

 if one did not know one might imagine that in the final stage the Insect was bound 

 to be a cripple. The legs and wings and long antennae are not all fixed up in a general 

 wrapper and immovable as in moth chrysalids, but are separately cased and folded 

 along the front of the body. A remarkable feature is the provision of a pair of 

 jaws which are different from those it possessed as a grub, and different from the 

 mouth-parts of the perfect Insect. They are indeed temporary developments to 



Photo: by] [H. Mam, F.E.S. 



Cocoon and Chrysalis. 

 The lace-wing grub, having finished its course as a destroyer, spins a cocoon 

 in which it passes through the winter — still in the grub stage — and becomes a 

 chrysalis in the spring. In the latter condition it is provided with a pair 

 of jaws specially for cutting off the upper end of its cocoon before the 

 emergence of the complete lace-wing fly. Thr<^'e times the actual size. 



