THE HOP FLEA-BEETLE. 83 



beetle and that the eggs of the latter were so minute that the larval 

 parasite required several of them to nourish and bring it to maturity, 

 as observed of an egg-parasite of the Hessian fly. The parent, watch- 

 ing her opportunity, deposits an egg internally in the ovaries of the 

 flea-beetle, or in the passage-way therefrom, and the parasite larva, 

 taking up its residence there, consumes the eggs of the flea-beetle, 

 one after another, as they develop, whereby none of them will be 

 extruded until after the parasite has attained its growth. In con- 

 clusion he writes, " Most singular and truly wonderful as such a 

 provision of nature would be, it is the most probable conclusion I am 

 able to arrive at from past observations." 



METHODS OF CONTROL. 



Correspondents who have inquired for a direct remedy for use against 

 this species have been advised to experiment with all of the usual 

 flea-beetle remedies. These are, in brief, arsenate of lead, arsenate of 

 lead with resin-fishoil soap, Paris green with and without Bordeaux 

 mixture, Scheele's green, arsenite of lime with soda, dry Paris gi-een 

 with air-slaked lime, Bordeaux mixture alone, and kerosene emulsion. 

 According to Messrs. Eder, Quayle, and others, most of these remedies 

 have been tested more or less completel}^ without being found to be 

 thoroughly effective, owing to the great numbers of the flea-beetles and 

 the rapidity with which the tops of the hop vines grow. All remedies 

 that have been employed have been directed against the beetles only. 

 Unless the hop plants are sprayed nearly every day it is practically 

 impossible to keep them covered with any poison so as to entirel}^ pro- 

 tect them from the ravages of the " fleas."' Among other substances 

 tested Avere tarred boards and sheets, as for leafhoppers. On account 

 of the employment of cheap labor, chiefly Hindu, mechanical and 

 hand methods were found of some value. Snuff Avas found effective 

 on a small scale and finely powdered tobacco, such as is now on the 

 market as an insecticide, is to be tested. , , 



According to Messrs. Quayle, Eder, and others, the difficulties 

 encountered in the economic treatment of this species are due to twq 

 causes: (1) The continual emergence or appearance of tlie beetles, 

 rendering any method that has yet been employed, such as an arsen- 

 ical or contact S2:)ray, or any mechanical means of capture, such as jar- 

 ring, of only temporary value, and (2) the extremely rapid growth 

 of the young hop vines, making frequently repeated applications of a 

 spray or other direct remedy a necessity. 



AKSEXICALS. 



Arsouifi of lead. — Arsenate of UmkI, applied at the rate of about 1 

 pound in from 20 to 50 gallons of water, is advised for use against 



