336 J. T. PATTERSON. 



be stated here that the abortive larvae of Copidosoma are in no 

 way comparable to the asexual larvae of Litomastix as described 

 by Silvestri. 



II. NOTE ON THE LIFE HISTORY OF GNORIMOSCHEMA. 



In order to collect polyembryonic material it is essential to 

 know something about the life history of the host; especially is 

 this true in cases like Gnorimo schema in which the larval host is 

 a gall maker. Considerable attention has therefore been given 

 to a study of the life history of G. salinaris. 



The general habits of the Solidago gall moths were first made 

 known by Riley's ('69) studies on G. gallcBSolidaginis . According 

 to Riley this species winters over in the imago stage and may be 

 seen flying in the month of May. When the young plants 

 (Solidago nemoralis) are about six inches high the female moth 

 lays her egg either in the terminal bud or at the side of the stalk 

 immediately below the bud. The young caterpillar upon hatch- 

 ing burrows into the stalk and starts the development of the gall. 

 By the first of June the gall has just begun to form and contains 

 a larva about one-third grown. The larva and its ellipsoidal 

 gall reach their full size by the middle of July. The caterpillar 

 which now measures over half an inch in length prepares for the 

 change into the chrysalis state by first eating a round passage- 

 way through the wall well toward the upper end of the gall. The 

 orifice is then closed by a secretion of liquid silk, which hardens 

 to form a silken plug. After closing the orifice, the caterpillar 

 lines the passage-way and the walls with a delicate silk, and then 

 transforms into a shiny, mahogany-brown pupa, about a half 

 inch long. The moths begin to emerge about the middle of 

 August and continue to appear until the beginning of October. 



Many phases of the life history of G. salinaris are similar to 

 those of G. gallaesolidaginis , but there are some important differ- 

 ences. The earliest date at which galls of the marsh goldenrod 

 have been secured was June 12, 1914, and at that time many of 

 the galls were well started. Between June 12 and 15, 63 galls of 

 various sizes were collected and examined. They varied in size 

 from 8 to 12 mm. in length and from 4 to 17 mm. in transverse 

 section. In shape the galls also vary greatly. Some are distinctly 





