IN'SECTS ETC., INJURIOUS TO VARIOUS CR.OPS 



1223 



Plot I : treated vnth " Oueria " powder — 321 larvae 



" 2 : " " nicotine solution — 163 



" 3 : untreated — 272 " 



In neither of the two vineyards did the " Queria " powder act, and the ni- 

 cotine soUition and " Xikotin-Florkus " powder also failed to give good results. 

 In the course of the summer, however, it was observable that the grape treat- 

 ed with nicotine solution was healthier, and that the stocks untreated and 

 those treated with nicotine powder contained many grapes of inferior value. 

 Bv adding cotton oil soap to the nicotine its effectiveness is increased. 



The control measures undertaken in autumn were only carried out with 

 nicotine solution. Two \4neyards were treated from the 20th or 22nd July 

 with a preparation of 1.5 % strength to which cotton oil .soap had been added, 

 so that the grapes were completely wetted. 



The vineyards were 5 years old ; in one there were found in the middle 

 of September, on 50 stocks of each plot, the following number of grapes at- 

 tacked by " Eudemis ". 



Plot I : treated with a 1.5 °o solution of nicotine . — 235 grapes 

 " 2 : not treated — 636 



An old vineyard showed, on 72 stocks per plot, the following numbers 

 of grapes attacked : 



Plot i: treatedwitha 15 % solution of nicotine . . . — 1573 grapes 



Plot 2 : not treated — 7475 



The effectiveness of control by nicotine in autumn was very remarkable. 

 The grapes were more developed, while the untreated plots contained bunches 

 with but few grapes. 



Nicotine acts most effectively when dissolved in water and applied 

 under strong pressure to the inflorescences and bunches. 



Many vine-growers mixed the tobacco juice with Bordeaux mixture ; 

 they afterwards added a little soap, and then the whole was spread on the 

 stocks by means of ordinary spra^^ers. Success in also obtained in this way, 

 although the ntimber of parasites killed is not ver\' high. The process, 

 however, has one disadvantage, namely, that the mixture used for control 

 is too adhesive, remains too long on the grapes, and is difticttlt to remove 

 by the rain. The grapes thus acquire a bitter taste due to the sulphate of 

 copper. Owing to this fact many mtists were found to have a bitter taste 

 in 1915, which is the reason why this method of control is not recommended 

 by the author. 



951 - Gryl/us servillei, an Injurious Orthopteron in New Zealand. — Clifton- e., 



in The Journal of A'^riculiitrc, Vol, XII, Mo. 3, pp. 187-1S9. W'=llin<,rton, 1916. 



The black cricket {Gryllus servillei) often, during the summer, causes 

 considerable damage in some districts of New Zealand. Generally the lands 

 to suffer most are those recently improved, where there are abundant pools 

 of water and great humidity. 



As means of control it is advised : i) to drain the pools ; the numerous 



INSECTS 



INJURIOUS 



TO VARIOU-- 



CROP.S 



