76 



SOME INSECTS INJURIOUS TO TRUCK CROPS. 



of this species in earlier years, reported, under date of July 11, as 

 follows : 



The flea-beetles have been so numerous that they have stripped every portion 

 of the yard this season. I have noticed these last three days that they are all 

 disappearing, but they all disappeared last season about this time and a second 

 brood came about the middle of .July. 



This " second brood " was probably merely the first-developed gen- 

 eration of the year. 



This species has also come under the observation of various other 

 collectors and observers. During 1906 Mr. Frederick Maskew, while 

 working under the writer's direction in southern California, took 

 it generally in many beet fields. j\Ir. E. G. Titus, while coiiperating 



Fig. 13. — View of hopyard, showing how completely the hop flea-beetle keeps down the vines. 

 Note occasional vine that grows up. Agassiz, B. C, June 24, 1908. (Original.) 



with this Bureau in the investigation of sugar-beet pests, found it 

 abundantly, and many of the locality records given under the head- 

 ing " distribution," in California, Utah, Idaho, and other States are 

 from specimens collected by him on sugar beet in 1905, 1907, and 1908. 

 Writing of this species in July, 1908, Mr. I. J. Condit stated that 

 the beetles were then very common in the vicinity of Chino, Cal., on 

 Chenof odium album and C. rurale. 



METHODS OF ATTACK, FOOD HABITS, AND GENERATIONS. 



This flea-beetle affects both surfaces of a leaf, gnawing through 

 the skin and devouring the pulp, usually leaving the skin on the op- 

 posite side entire; this later becomes discolored, forming yellowish- 



66— VI 



