THE -WrHEAT MIDGE. 99 



163(a). With reference to change of seed of the same variety 

 it should be borne in mind that it is advisable to obtain the fresh 

 seed from a soil and climate better and earlier than those of the 

 locality in which it is sown. In America, where our winters are 

 so prolonged that vegetation in the summer months progresses 

 as in a hothouse, it seems very probable that seed obtained from 

 the north would ripen earlier for a year or two in southern dis- 

 tricts, than acclimated varieties. (2) 



163(b). The remedial measure which appears to be immediate- 

 ly suggested by a study of the habits of the wheat midge, is of 

 the simplest description, and everywhere practicable. It will be 

 seen from paragraphs 152, and 156, that the maggot of the 

 midge, previous to assuming its larvae condition, buries itself an 

 inch or a little more below the surface of the ground. That 

 when the time arrives for their assuming the fly state, they wrig- 

 gle themselves to the surface for that purpose. It is only by a 

 series of alternate contractions and expansions of one side and 

 the other that they can make their way up from an inch below 

 the surface to the light and air, for they possess no feet or other 

 exposed members when in the pupa case. If, therefore, the 

 pupa be buried, say six inches below the surface, it is permanent- 

 ly imprisoned, for nature has not provided any apparatus to ena- 

 ble it to effect its escape under such circumstances. If, there- 

 fore, at any time between August and May of the following year 

 the ground be ploughed to a depth of at least 6 inches, and in 

 such a way that the furrow slices lie as compactly as possible, 

 there can be no doubt that a vast majority of the pupse will per- 

 ish from inability to escape from their imprisonment. 



163(c). But how much greater will be the probability of every 

 individual pupa perishing if the ground be ploughed seven inches 

 deep immediately after harvest, and left untouched until the fol- 



(2) See paragraph, or rather note to paragraph 120, page 86. 



