84 WALL'S MANUAL 



first three segments of the body, and the sides ai'O 

 also marked on the margin with yellow j the body is 

 somewhat hairy. The head is armed with powerful 

 jaws, and gradually tapers to a point, while the tail 

 terminates abruptly, as if cut off. The parent fly 

 deposits her eggs amongst the lice in order to insure 

 a supply of food to each grub. These eggs are soon 

 hatched by the heat of the sun, and the young grub 

 immediately commences crawling about the leaf. 

 Being blind, it incessantly gropes and feels around on 

 either side in search of plant lice, its natural food. 

 When ready to change, the "syrphus" grub fastens 

 itself to a leaf or stalk by means of a glutinous secre- 

 tion from its own body, and the outer skin contract- 

 ing into a pear-shaped case soon hardens by expo- 

 sure to the air, and the pupa is formed inside. After 

 a few days, during the heat of summer, the perfect 

 fly emerges from a hole at the blunt end of the case, 

 to lay eggs amongst other colonies of lice on neigh- 

 boring plants. The perfect fly is about seven- tenths 

 of an inch across the wings, which are two in num- 

 ber and transparent. The body is, generally, more or 

 less banded brown, or black and yellow, and appears 

 like that ofa small wasp. This fly has a peculiar 

 habit of hovering on the wing, apparently without 

 motion or exertion, during the heat of the day, near 

 or over flowers. These insects are of essential aid to 

 farmers and planters, as their young materially 

 diminishes the numbers of lice which infest vegeta- 

 tion. 



The Lady Bird. The lady bird is a most valuable 

 aid to the cotton planter, as it destroys the cotton 

 lice by millions, and is most plentiful, where they 



