170 



ZOOLOGY. 



attacks of the midges commence when the ears begin 

 to emerge from the leaf-sheaths, and are continued 

 throughout the flowering time of the wheat. At 

 night the female pierces the glumes with her ovi- 

 positor, and lays three to ten perfectly transparent 

 eggs in each flower. Each midge lays eggs in several 

 flowers, but two or more midges may use the same 

 flower for this purpose, so that as many as thirty 

 maggots may be found in one bloom (Fig. 112). 

 The maggots, which are hatched out in a week, creep 

 down to the ovary and suck its juices. If many 

 maggots live in one flower it is sure to die, but if 

 there are only a few it may produce a grain, though 

 this may be small. Ears infested by the maggots 

 develop yellow spots later on ; many ears remain 

 quite empty, and consequently thin and upright. 

 Full-grown maggot : ^ inch ; straw yellow to chrome 

 yellow ; quite transparent when very young. Is 

 fully developed in three weeks, and then lets itself 

 fall to the ground (July or August). Becomes a 

 pupa the following spring; fourteen days later the 

 midge escapes. 



Family : Eostratse {Crane Flies, Baddy Longlegs). 



These very long-legged gnats live on the juices of 

 plants, and do not sting. The larvseare legless, with- 

 out a hard well-marked head ; those of most species 

 live in mouldering plant parts {e.g. rotten wood), 

 or the decaying manures of our fields and meadows. 

 A few species, however, are very destructive, since 

 they injure roots and other parts of cultivated plants. 

 The adult and larval stages of all the injurious kinds 

 are not yet distinguished. We know that the larvje 

 of the yellow and spotted Tipula Tnaculosa are chiefly 

 destructive in sandy soil ; while more binding clay 

 soil and rich garden earth are infested by the larvae 

 of Tipula oleracea (Fig. 113), and damp meadows by 



