350 



INJURIOUS AND BENEFICIAL INSECTS OP CALIFORNIA. 



Life History. The life history of this fly is not fully known, but 

 probably greatly resembles thai of the serpentine leaf-miner in the 

 more important aspects. 



Nature of Work.— Figure 347 shows the work of this fly, which con- 

 sists in the making of large numbers of mines just, under the upper 

 epidermis of the leaves. The infested plants become sickly and greatly 

 disfigured by the attacks. 



Distribution. — The chrysanthemum leaf-miner has been quite 

 destructive to plants at Oakland during the past year (1914). It was 



Fig. 347. The chrysanthemum leaf-miner, Phytomyza chrysanthemi Kowarz. 

 Flies and mines on cineraria leaf. Enlarged three times. Specimens received 

 from F. Seulberger, Oakland. (Original) 



lirst taken and forwarded to the writer by Mr. Fred Seulberger, county 

 horticultural commissioner of Alameda County. 



Food Plants.- J\l any of the C&mpositce, including chrysanthemum, 

 cineraria, Eupatorium, marguerite and Shasta daisy are attacked. 



Control.— Prof. J. U. Sanders found that the eggs as well as the 

 larvae and newly formed pupa? within the mines could be killed with an 

 application of one part of "black leaf 40" to 400 parts of water, and 

 thai the pupa' of all ages could be killed by increasing the proportions 

 I to 200. 25fl 



■ r Mr. Ec. Rnt., V, p. 172, 1912 



