New York Agricultubal Experiment Station. 627 



Prof. Slingerland writes me that in 1893 he bred a Spinach-leaf 

 Miner at Cornell University, which Dr. Williston determined as 

 Scatojyhaga sp. 



Although '' leaf miners " have been observed on beet, spinach, 

 and in fact on Chenopodium, for the past ten years, it is evident 

 from the above gleaned facts that they were not considered of very 

 great economic importance previous to 1882. In fact, tlieir injury 

 to beets was of such a nature as not to attract attention unless the 

 leaves were used for "greens." It is also quite evident that the 

 flies which caused the damage were not widely known. 



In the month of August, 1894, I collected near Queens, N. Y., 

 beet leaves infested with a maggot that was new to me. During 

 September, Mr. Backus, of Newton, N. T., told us that some insect 

 was injuring his spinach. Mr. Lowe visited Mr. Backus' farm, and 

 found an unknown maggot mining the leaves. On September 25tli 

 the same trouble was noticed in spinach leaves on the farms of 

 Mr. O'Donnell and Mr. Augustine, near Jamaica, K. Y. In many 

 cases every leaf on all the plants covering small areas would be 



mined. 



Throughout the past summer it has been impossible to find a 

 plant of Lamb's-quarters that did not have some of these maggots in 

 the leaves. During the fall they have attacked the spinach so 

 severely that it w^as impossible for many of the farmers to sell their 

 spinach after carting it to market. The injury to beets has not 

 been so marked. 



Life History.— All the flies reared by Dr. Lintner were obtained 

 during July and August. Mr. Koebele's material was all bred dur- 

 ing the month of June. In September, 1892, material was sent 

 from California to Dr. Kiley from which the adults issued Septem- 

 ber 8th. The following year in October more material was for- 

 warded from California^ to the Division of Entomology at 

 Washington, but no adults were obtained from this. 



Spinach and beet plants whose leaves were infested with maggots 

 were transplanted to breeding cages October 25, 1894. All had 

 pupated November 5th. Flies commenced to issue in the cages as 

 early as March 27, 1895, but the majority of them did not issue 

 until about April 16, 1895. This proved that part at least of the 

 flies pass the winter in the puparium. Brobably they do not issue 

 as early in the field, at least in this locality. The breeding jars 



