THE HOP FLEA-BEETLE. 



79 



The following account of the life history and habits of this species 

 as it occurs in Britisli Columbia is taken from Mr. Quayle's manu- 

 scripts : 



LIFE HISTORY AND HABITS. 



The adult. — The beetle appears very early in the spring and, according to 

 reports, patiently awaits the coming of its food plant. This early attack of 

 the beetle as the plants are bursting through the ground and before the leaves 

 are fully expanded is one of the things that makes control work difficult. 

 Before the hops appear the beetles are 

 known to attack the nettle, and often com- 

 pletely riddle the leaves. They also attack 

 other plants, and have been seen, and evi- 

 dence of their work noticed, on potato, 

 mangel, beet, turnip, doclv, lamb's-quarters, 

 pigweed, and red as well as white clover. 

 None of these plants is attacked, however, 

 in preference to hops and it is rarely that 

 they are found at this season on anything 

 but hop vines. In one or two cases they 

 were observed in some numbers on potato, 

 at a considerable distance from hop vines. 

 On a small field of hops that was deserted 

 last year on account of this flea-beetle and 

 planted to clover, the leaves of the latter 

 were considerably eaten. 



The first appeai-ance of the beetles in this 

 section, according to Mr. Hulbert, was 

 fourteen years ago, and they have been 

 attacking his hops for the past five years. 

 The beetles jump very readily when dis- 

 turbed, but fall to the ground, usually not 

 far from the base of the vine. Experiments 

 to determine the power of jumping, which is 

 an important factor in control work, indicate 

 that they may not jump more than a foot 

 in the vertical and about a foot and a half 

 in the horizontal. 



Feeding occurs almost entirely on the 

 upper surface of the leaves, where they 

 eat out small, nearly round holes al)out 

 one-eighth of an inch in diameter. This is 

 continued until the leaf is reduced to a network and finally nothing but the 

 main ribs remain. Many of the vines grew to a height of three or four feet, 

 then the foliage was completely stripped off, leaving the dead stalks, which 

 may still be seen in the fields. Many of the vines are thus killed to the 

 gi'ound. Strings were put in place in 1908 in anticipation of the usual croj), 

 but were taken down and saved for another year, as the vines that started 

 afterward were too late to make a crop. Cultivation was stoppetl and a 

 thousand sheep were imported from California by the Horst Company to 

 feed in their yards. 



The beetles, with their more or less cone-shaped bodies, readily make their 

 way through anything into which they can get their heads, and our experi- 



FiG. IG. — Trained hop shoots stripped 

 by flea-beetlo. (Original, i 



