172 ZOOLOGY. 



the destruction of the standing corn begins. The 

 larvae are hatched out in summer, during the later 

 part of which, and during autumn, they devour plant 

 roots ; after hybernating, they again attack the under- 

 ground parts of plants the following spring. They 

 devour most readily the roots of grass and corn, but 

 also those of clover, rape, and several other plants, 

 including some found in flower and kitchen gardens. 

 They are mainly injurious either in autumn or spring, 

 according to the nature of the plants attacked. 

 Young grain plants are killed by them, older ones 

 usually not. On fields where winter corn grows 

 they therefore do most damage in autumn, while this 

 is the case in spring on land where summer corn is 

 cultivated. They are sometimes harmless, since they 

 can also feed on roots left behind in the ground. The 

 larva do not limit their ravages to underground 

 parts ; in the evening, and also in the daytime during 

 dark damp weather, they devour parts of the first 

 leaves of very young corn plants, though the damage 

 thus effected is often inconsiderable. In May the 

 larva is ready to pass into the pupa stage ; it comes 

 near the surface and becomes a brown pupa, bearing 

 small spines on the abdominal rings. After a rest 

 of fourteen to seventeen days, the pupa works its 

 way upward till the front part of its body sticks out 

 of the soil. The fly then escapes. Enemies : Mole, 

 shrews, wagtails, grasshopper warbler, rook, gulls. 

 Remedies: When the maggots are very destructive 

 in gardens they may be collected, preferably in wet 

 weather, since they then leave the soil during the 

 day. If they appear to an injurious extent on 

 summer corn, the fields should be rolled in April 

 (either with the ordinary or the spiked roller). At 

 the time (June) when the crane flies swarm about 

 the flelds and meadows in flocks, thousands of 

 individuals can easily be caught with a net. 



