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time. A single female begins the gall, whose young soon 

 multiply, leaving the gall in September." 



Acronycta populi. RILEY. THE COTTON-WOOD DAGGER. 

 (LEPIDOPTERA. ACRONYCTAD^;.) 



The caterpillars of this moth are found on the leaves of 

 the Cotton-wood. The caterpillar is easily recognized by 

 " its body being covered with long, soft, bright-yellow hairs 

 which grow immediately from the body, part on the back, 

 and curl round on each side." The head is black, and on 

 the top of five joints, is a straight black brush. When at 

 rest they have a habit of curling round upon a leaf.' There 

 are two broods each year, the first brood appearing during 

 the month of June, the second the last t>f August. 



The chrysalis is surrounded by a pale, yellow, silk 

 cocoon, and is generally found in some sheltered place, 

 such as a chink in the bark of a tree, or under the cap of 

 some fence. Mr. Riley has bred three distinct parasites 

 from the larva of this moth, which undoubtedly serve to 

 keep them in subjection. Although not strictly gregarious 

 in habit, they are found in clusters when young, and can, 

 at that time be easily destroyed by gathering. 



The Locust suffers from the borers to an alarming 

 extent throughout Illinois. It is discouraging to find the 

 main trunk of a whole row of trees riddled through and 

 through with these depredators, and yet it is frequently 

 seen, and unless the natural enemies come to the rescue, 

 a healthy Locust tree will be the effect of the imagination. 

 Only two or three trees remain to represent the long row 

 which once aiforded shade on the northern extremity of 

 Elizabeth street. The most numerous of which are the 

 Clytus Rbbinice and Xykutes Robinice. 



