C|e Canadian (f nttmtolagist 



Vol. II. TORONTO, NOVEMBER 15, 1869. No. 3. 



THE GKAPE-SEED INSECT. 



(Isosoma vitis, n. sp.) 

 BY W. SAUNDERS. 



In Vol. i., No 3, page 20, of the Canadian Entomologist, I published a 

 description of a larva found infesting the seed of the grape, and in the 

 Canada Farmer for October 15, 1868, page 316, a fuller description of its 

 habits and destructive powers, and ventured the opinion that it would 

 probably produce, when mature, a small curculio. In this I was in error, 

 for the perfect insect proves to be Hymenopterous, a small four-winged fly 

 belonging to Isosoma, and as it is believed to be undescribed, I propose for 

 it the name of vitis {Isosoma -vitis, n. sp.). The following notes on its his- 

 tory were made subsequent to the date of the issue referred to. 



In October I detached a larva from the inside of the seed, and placed it 

 in a small glass cell between two plates of glass, in which state it remained 

 until early in January, when it became a chrysalis, having first attached 

 itself to the sides of the cell by a few short silky threads. It had now con- 

 tracted in length, become nearly oval, and assumed a yellowish tint, with a 

 few short loose silky threads adhering 'to different parts of its surface. On 

 the 11th of February I examined some seeds and found the larva within 

 still alive and active, just as it appeared in the fall. On the 7th of July 

 further specimens were opened and the inmates found soft and motionless, 

 these appeared to be in the chrysalis state, but I did not examine tbem wkh 

 sufficient care to enable me to be positive. During the remaining part of 

 July I looked many times into the bottles in which the grapes were enclosed 

 but could not discover anything. On the 9th of August, feeling sure that 

 the time for the appearance of the insect must be fully come, if not already 

 past, I resolved on a thorough search for it. As soon as the contents of the 

 bottles had been emptied on a piece of white paper, I observed a number of 

 small four-winged flies among the dried-up grapes. They were all dead and 

 stiff, some of them more brittle than others. From the observations made I 

 should judge that they made their escape from the middle to the end of 



