46 



MANUAL OF VEGETABLE-GARDEN INSECTS 



References 



Ky. Agr. Exp. Sta. Bull. 40, pp. 46-51. 1892. 

 Coquillett, Insect Life, 7, pp. 381-383. 1895. 

 U. S. Div. Ent. Bull. 33, pp. 75-77. 1902. 



The serpentine leaf-iiimer, Agromyza pus ilia Meigen 



The leaves of cabbage, turnip, radish and rape are sometimes 

 disfigured by narrow, tortuous mines caused by a small, trans- 

 lucent yellow maggot about J inch in length. This insect has 



also been found mining 

 the leaves of potato, 

 spinach, beet, water- 

 melon, and pepper, as 

 well as many wild and 

 ^^ f )rage plants. When 

 ^ mature, the maggots 

 transform within the leaf 

 into brownish puparia 

 about -^2 inch in length. 

 In the summer about 

 ten days are spent in 

 this stage. The fly 

 (Fig. 38) is from -^ to 

 ■^ inch in length, shining black and marked with yellow in a 

 most variable way. The flies deposit their small, white, oval 

 eggs, about yw^ inch in diameter, in the tissue of the leaf 

 on the underside. The eggs hatch in three to eight days. 

 The time required for each generation varies from twenty- 

 three to forty days depending on the temperature. Breeding 

 is continuous throughout the growing period and the number 

 of generations depends on the length of the season. 



Fig. 38. — The fly of the serpentine leaf 

 miner (X 20). 



Reference 

 Webster and Parks, Jour. Agr. Research, 1, pp. 59-87. 1913. 



