CEREAL GRASSES. 23 



rust is more injurious on the Continent than in our 

 climate. 



Flies are great enemies to wheat crops. The striped 

 Wheat-fly (Chlorops lineata) lays its eggs in June, when 

 the spikes are just emerging from the sheaths ; in about 

 fifteen days the eggs are hatched, then the maggots bore 

 the stem and creep up the spike; then they change to 

 pupse, and afterwards to flies, yellow in colour with a 

 black triangle on the crown. In September the young 

 flies lay eggs upon the rye and other corn recently sown. 

 The Ribbon-footed fly (T&niopus) are still more harmful 

 to wheat, for they live in the base of the stem and either 

 destroy it altogether or make one side of the ear and 

 most of the grain empty and shrivelled. 



Wheat midges (Cecidomyia tritici) convey their eggs 

 into the stems whilst the wheat is in flower, and when 

 they are hatched the young larvae abstract the juices 

 from the grain and cause it to shrivel. The midge itself 

 is an orange insect with splendid black eyes. 



Ear-cockles are also virulent enemies to the wheat 

 crop ; the eggs hatch in the ovary. These worms are 

 transparent, then yellowish, and somewhat opaque or 

 semi-transparent, composed of many rings and a narrow 

 distinct head ; they attain the fourth of an inch in length 

 and after being dried for six years have been reanimated 

 by water. The cavities of the grain, when filled with 

 the Ear-cockle {Vibrio tritici), form white balls of silky 

 fibre, which dissolve instantly when plunged in water, 

 liberating hundreds of the worms. 



T. Spelta, Larger Spelt, differs from true wheat in ad- 

 hering to the chaff; it is much cultivated in the warmer 

 districts of South-eastern Europe and the African and 



Asiatic shores of the Mediterranean. 



4 



