86 WALL'S MANUAL 



is an insect which measures nearly half an inch in 

 length, of a yellow color, with twelve large and small 

 black spots on the wing-cases, and four small black 

 spots on the thorax, which does considerable damage 

 to the cucumber, melon and squash vines, by devour- 

 ing the leaves, so as sometimes to disfigure and de- 

 stroy the plants, which should not be confounded 

 with the beneficial lady bird. The latter can easily 

 be distinguished from this destructive bug, both by 

 size and color, the useful lady bird being only one- 

 sixth or one- seventh of an inch in length, and of a 

 bright red, almost scarlet, color, with black spots ; 

 while the other, as before said, are yellow, with black 

 spots, and one-half of an inch in length. 



The Lace- Wing Fly. The larva of the lace- wing 

 fly is furnished with two long and sharp jaws, by 

 means of which it seizes the cotton-louse, and, in a 

 few minutes, sucks out the juices, leaving merely the 

 white, dried skins. The eggs of this fly are very 

 singularly placed at the end of a thread-like filament, 

 fastened on the under side of the leaf, and generally 

 near a colony of lice, in clusters of a dozen or more 

 together, causing them to appear, to the casual 

 observer, like a bunch of fungi. The eggs being- 

 hatched in the midst of the cotton-lice, the young 

 larvae commence the work of extermination, seizing 

 the younger lice in their jaws, and holding them in 

 the air, sucking out their juices, and finally throwing 

 away the empty skins. The Iarva3 of this insect are 

 not quite one-fifth of an inch in length, and are 

 furnished with an apparatus at the extremity of 

 their tails, by means of which they are capable of 

 sticking to the leaf, even when all their feet aro 



