THE AMERICAN WHEAT-FLY. 597 



the winter." On the 14th of August, 1841, she visited 

 again the field of wheat where, on the 25th of July, she 

 had found great numbers of the maggots, and observed 

 that " a very few of all that multitude were left. On rub- 

 bing the ears, their silvery coverings glistened in the sun- 

 shine, and floated away on the breeze. A warm rain had 

 fallen between these visits." 



In an account of the damage done by these insects in 

 Vermont, in the summer of 1833, it is stated that, " after 

 a shower of rain, they have been seen in such countless 

 numbers on the beards of the wheat, as to give the whole 

 field the color of the insect."* Mr. Elijah Wood, of 

 Winthrop, Maine, in a short communication, written in 

 the summer of 1837, made the following remarks : " This 

 day, 9th of August, a warm rain is falling, and a neighbor 

 of mine has brought me a head of wheat which has become 

 loaded with the worms. They are crawling out from the 

 husk or chaff of the grain, and were on the beards, and 

 he says he saw great numbers of them on the ground." f 

 From these observations, and from remarks to the same 

 effect made to me by intelligent farmers, it appears that 

 the descent of the insects is facilitated by falling rain and 

 heavy dews. 



Having reached the ground, the maggots soon burrow 

 under the surface, sometimes to the depth of about an inch, 

 those of them that have not already moulted casting their 

 skins before entering the earth. Here they remain, without 

 further change, through the following winter. During the 

 month of May, I have seen specimens still in the larva form, 

 in the earth wherein they had been kept during the winter. 

 It is not usually till June that they are transformed to pupa?. 

 This change is effected without another moulting of the skin : 

 not the slightest vestige of the larva-skin being found in the 

 earth in which some of these insects had undergone their 



* New England Farmer, Vol. XII. p. 60. 

 t Ibid., Vol. XVI. p. 61. 



