DIPTERA. 443 



middle of August ; and they are very rarely found in the grain at 

 the time of harvest. Some persons have slated that they are 

 transformed to flies in the ears of the grain, having probably mis- 

 taken the cast skins found therein for the shells of the chrysalis 

 or pupa. We have good reason for believing that the maggots 

 burrow in the ground, and remain there unchanged, in a torpid 

 state, through the winter. Whether, on the approach of spring, 

 they again cast oft' their skins, in order to become pupae, or 

 whether the skin hardens and remains as a shell to protect the 

 pupa, has not been determined ; but it is probable that the skin 

 is not cast off till the insect comes forth in the winged form. 

 The last change seems to occur in June and July, when great 

 numbers of the flies have been seen, apparently coming from the 

 ground, in fields where grain was raised the year before. 



Several cases of the efficacy of fumigation in preventing the 

 depredations of these insects are recorded in our agricultural 

 papers.* For this purpose brimstone has been used, in the pro- 

 portion of one pound to every bushel of seed sown. Strips of 

 woollen cloth, dipped in melted brimstone, and fastened to sticks 

 in different parts of the field, and particularly on the windward 

 side, are set on fire, for several evenings in succession, at the 

 time when the grain is in blossom ; the smoke and fumes thus 

 penetrate the standing grain, and prove very offensive or destruc- 

 tive to the flies, which are laying their eggs. A thick smoke 

 from heaps of burning weeds, sprinkled with brimstone, around 

 the sides of the field, has also been recommended. Lime or 

 ashes, strown over the grain when in blossom, has, in some cases, 

 appeared to protect the crop ; and the Rev. Henry Colman, the 

 Commissioner for the Agricultural Survey of Massachusetts, says 

 that this preventive, if not infallible, may be relied on with strong 

 confidence. f For every acre of grain, from one peck to a bushel 

 of newly slacked lime or of good wood ashes will be required ; 

 and this should be scattered over the plants when they are wet 

 with dew or rain. Two or three applications of it have some- 

 times been found necessary. Whether it be possible to destroy 



* Among others, see " The Cultivator," Vol. V., p. 13G. 



< " Third Report on the Agriculture of Massachusetts," p. 67. 



