182 ZOOLOGY. 



September, or October, should not always find suitable 

 corn plants upon which to deposit their eggs. In such 

 cases grasses are used. Remedies : Sowing the summer 

 corn as early as possible, that it may be developed to 

 a stage which is unsuitable for the purpose of egg- 

 laying, before the flies appear. The winter seed, 

 however, must be sown as late as possible, so that the 

 second generation of flies may find no corn plants fit 

 to lay their eggs upon. Bearded wheat, especially the 

 strongest varieties, should be sown in preference to 

 awnJess wheat. Careful tillage and suitable manuring, 

 so that strong plants of rapid growth may be pro- 

 duced. 



The Frit Fly (Ghlorops, or Oscinis frit) 



(Fig. 120, C) is about one-tenth of an inch long, shining 

 black, with a metallic sheen. Legs short, feet yellow. 

 Maggot (Fig. 120, A) yellowish white, about one-eighth 

 of an inch long, cylindrical, and tapering in front. 

 Usually three generations, 1. The maggots of the first 

 generation are found during May, in the lower part of 

 the haulm of summer corn (especially oats and barley) ; 

 the plants attacked either die off entirely, or some 

 haulms develop further, remaining small, however, 

 and yielding only a few light grains. The base of 

 the haulm thickens abnormally, but the growth in 

 length is always small ; the leaves, too, grow badly, 

 first becoming yellowish at the tip, and then entirely 

 yellow or reddish. The symptoms of disease are 

 exhibited to a less or greater extent, according as 

 few or many (even up to ten) maggots inhabit the 

 base of a plant. The shining brown pupae (Fig. 120, 

 B) are found in the lower part of the haulm, or 

 between the leaf-sheath and the haulm (Fig. 120, D). 

 The adult insect is on the wing at the end of May and 

 in June. The first generation often appear on wild 

 or meadow grasses, and are chiefiy seen on summer 

 corn when this is sown late or develops slowly. 



