xxiii INSECTA : DIPTERA 357 



the shape of the end of the body. In the male this is much 

 thickened and blunt, whilst in the female the slender 

 abdomen is terminated by two pairs of pointed appendages 

 which are used in egg-laying. 



When the eggs are to be deposited, the female 

 fly descends, usually amongst grass stems, and 

 standing on her last pair of legs, with her body in a vertical 

 position, she lays the eggs one by one, dropping them on 

 the surface and pushing them into the ground with the two 

 pairs of appendages which hold the egg and form the 

 ovipositor. Each time the insect settles she lays a few eggs, 

 depositing altogether from 200 to 300 before she has finished. 



The larvae live entirely underground, feeding 

 ' on the roots of grasses as well as on dead vegetable 

 matter; they often do much damage in corn-fields, and 

 are known to farmers 

 as " leather - jackets," 

 owing to the toughness 

 of their skins. The 

 mouth has two strong Fig. 284.— Larva of Tipula ( x SJ). 



toothed mandibles and (A "leather-jacket.") 



a toothed labrum. The head segments are telescoped in on the left. 



against which the man- 

 dibles work. The palps are short and the maxillae rudi- 

 mentary. These parts are difficult to see at first in a 

 specimen under examination, as the head segment is then 

 telescoped within the next, but if gently pressed, the head 

 will be everted and the feelers and mandibles become visible. 

 The larva may grow to an inch in length. It is earth- 

 coloured, and not easy to detect quickly. At the tail-end of 

 the segmented body are some small, sharply pointed, stiff 

 processes and some fleshy lobes surrounding two terminal 

 spiracles. 



The larvae which are hatched out in the spring, 

 pupate and give rise to winged Crane-flies in the 

 same summer. From the eggs laid by these arises a second 

 brood of larvae which hibernate throughout the winter, only 

 pupating the following spring. After the last larval skin 

 has been shed, the pupa, which is then disclosed, assumes a 

 vertical position, and gradually works its way up to the 

 surface of the ground, projecting its head above the surface 



