92 MANUAL OF VEGETABLE-GARDEN INSECTS 



tapers towards the head and is obliquely truncate posteriorly. 

 When mature, the larva usually deserts the leaf and enters 

 the earth, where, at a depth of two or three inches, it changes 

 to a brownish puparium, about ^ inch in length. Sometimes 

 the puparia are found in the dead and rotting leaves on the 

 ground. The flies emerge in two weeks to twenty-five days 

 and soon lay eggs for another brood. In central New York 

 there are three generations and a partial fourth annually. 



The spinach maggot is most injurious to spinach and chard, 

 and beets when used for greens. The injury to the leaves of 

 beets, mangels and sugar-beets also decreases the size of the 

 root-crop. When these crops are grown for seed, the quantity 

 produced is often seriously lessened by the partial defoliation 

 of the plants by the maggots. 



Control. 



No satisfactory method of preventing the damage by the 

 spinach leaf-miner has as yet been devised. Clean culture and 

 the destruction of the insect's wild food plants, lamb's quarters 

 and other weeds will be of some value in decreasing the degree 

 of infestation. In some localities growers avoid a bad infes- 

 tation in spinach by growing the crop late in the fall and early 

 in the spring. 



References 



N. Y. (Geneva) Agr. Exp. Sta. Bull. 99. 1896. 



Jablonowski, Tiereschen Feinde der Zuckerriibe, pp. 303-315. 1909. 



Cameron, Ann. Appl. Biol., 1, pp. 43-76. 1914. 



The Beet Leafhopper 



Eutettix tenellus Baker 



In the western states from Idaho, Nebraska and Texas, 

 westward to the Pacific and southward into Mexico, sugar- 

 beets, table beets and mangels are subject to a disease known 

 as curly-leaf, the exact cause of which is not fully understood. 



