﻿683 
  

  

  counted, 
  and 
  the 
  count 
  was 
  only 
  taken 
  after 
  an 
  interval 
  of 
  some 
  weeks, 
  

   on 
  the 
  20th 
  June. 
  By 
  that 
  time 
  the 
  larvae 
  are 
  half-grown 
  and 
  are 
  

   found 
  in 
  a 
  knot 
  of 
  more 
  or 
  less 
  eaten 
  flowers. 
  Such 
  " 
  nests 
  " 
  are 
  easy 
  

   to 
  count, 
  and 
  though 
  one 
  may 
  sometimes 
  be 
  empty, 
  this 
  is 
  counter- 
  

   balanced 
  by 
  the 
  fact 
  that 
  occasionally 
  two 
  larvae 
  are 
  to 
  be 
  found 
  in 
  

   one 
  nest. 
  The 
  results 
  in 
  the 
  66 
  plots 
  are 
  tabulated 
  : 
  — 
  Bordeaux 
  

   mixture 
  : 
  2 
  per 
  cent, 
  strength 
  was 
  quite 
  ineffective. 
  Evert's 
  tobacco 
  

   extract 
  : 
  In 
  all 
  cases 
  a 
  IJ 
  percent, 
  solution 
  of 
  this 
  product 
  was 
  used. 
  

   It 
  contains 
  a 
  guaranteed 
  10 
  per 
  cent, 
  of 
  nicotin. 
  Used 
  alone, 
  the 
  

   percentage 
  of 
  larvae 
  destroyed 
  was 
  89*9 
  ; 
  with 
  2 
  per 
  cent. 
  Bordeaux 
  

   mixture, 
  97*5 
  ; 
  with 
  | 
  per 
  cent, 
  soap, 
  29' 
  8 
  in 
  one 
  case 
  and 
  88*3 
  in 
  

   another 
  ; 
  with 
  2 
  per 
  cent. 
  Bordeaux 
  mixture 
  and 
  |- 
  per 
  cent, 
  soap, 
  

   72-9. 
  No 
  injury 
  to 
  the 
  vines 
  or 
  retarded 
  ripening 
  was 
  noticed. 
  

   Tobacco 
  extract 
  of 
  the 
  Austrian 
  Kegie 
  : 
  In 
  all 
  cases 
  a 
  IJ 
  per 
  cent, 
  

   solution 
  of 
  this 
  product 
  was 
  used. 
  It 
  contains 
  from 
  9 
  to 
  11 
  per 
  cent, 
  

   of 
  nicotin 
  (9 
  per 
  cent, 
  guaranteed). 
  When 
  spraying 
  on 
  the 
  19th 
  May 
  

   and 
  using 
  0*15 
  per 
  cent, 
  of 
  soap 
  the 
  percentage 
  of 
  larvae 
  destroyed 
  

   was 
  85*4 
  ; 
  with 
  J 
  per 
  cent, 
  of 
  soap, 
  79*1 
  ; 
  with 
  J 
  per 
  cent, 
  of 
  soap, 
  

   74' 
  3. 
  On 
  the 
  23rd 
  May 
  and 
  9th 
  June 
  J 
  per 
  cent, 
  of 
  soap 
  was 
  used 
  

   and 
  the 
  figures 
  were 
  36*5 
  and 
  28' 
  6 
  respectively. 
  It 
  will 
  be 
  seen 
  that 
  

   the 
  early 
  spraying 
  gave 
  good 
  results 
  and 
  that 
  the 
  addition 
  of 
  varying 
  

   strengths 
  of 
  soap 
  did 
  not 
  appear 
  to 
  influence 
  its 
  efficiency. 
  The 
  

   treatment 
  did 
  not 
  interfere 
  with 
  the 
  vines 
  in 
  any 
  way. 
  " 
  Excelsior 
  " 
  

   tobacco 
  extract 
  containing 
  10 
  per 
  cent, 
  of 
  nicotin 
  was 
  used 
  on 
  the 
  23rd 
  

   May 
  and 
  the 
  result 
  was 
  negative, 
  the 
  control 
  plot 
  being 
  less 
  infested, 
  

   A 
  IJ 
  per 
  cent, 
  solution 
  of 
  " 
  Schachenmuhle 
  " 
  containing 
  10 
  per 
  cent, 
  

   of 
  nicotin 
  was 
  sprayed 
  on 
  the 
  23rd 
  May. 
  In 
  spite 
  of 
  the 
  rainy 
  weather, 
  

   over 
  69" 
  6 
  per 
  cent, 
  of 
  the 
  larvae 
  were 
  killed 
  and 
  the 
  vines 
  were 
  not 
  

   injured. 
  Muth's 
  preparation 
  of 
  nicotin, 
  carbon-bisulphide, 
  and 
  

   petroleum-soap 
  emulsion 
  was 
  used 
  on 
  the 
  9th 
  June, 
  after 
  the 
  larvae 
  

   had 
  developed 
  somewhat. 
  It 
  destroyed 
  52 
  per 
  cent, 
  of 
  the 
  larvae 
  

   and 
  did 
  not 
  injure 
  the 
  vines 
  ; 
  earher 
  spraying 
  might 
  have 
  been 
  

   advantageous. 
  " 
  Elcotin 
  " 
  contains 
  3 
  per 
  cent, 
  crude 
  nicotin. 
  A 
  

   5 
  per 
  cent, 
  solution 
  was 
  used 
  on 
  the 
  20th 
  May 
  and 
  98*3 
  per 
  cent, 
  of 
  

   the 
  larvae 
  were 
  destroyed, 
  the 
  vines 
  being 
  uninjured. 
  Crude 
  nicotin, 
  

   sprayed 
  early, 
  is 
  therefore 
  a 
  useful 
  control. 
  " 
  Kebinol 
  " 
  is 
  used 
  in 
  a 
  

   25 
  per 
  cent, 
  solution. 
  Spraying 
  on 
  the 
  19th 
  May 
  resulted 
  in 
  16 
  per 
  

   cent, 
  of 
  the 
  larvae 
  being 
  killed, 
  and 
  it 
  is 
  therefore 
  inferior 
  to 
  the 
  cheaper 
  

   nicotin 
  preparations. 
  " 
  Ampelophil 
  " 
  was 
  useless 
  in 
  these 
  trials. 
  

   " 
  Golazin-Itotsi 
  " 
  contains 
  crude 
  nicotin, 
  soap, 
  crude 
  spirit 
  and 
  an 
  

   adhesive. 
  A 
  2 
  per 
  cent, 
  solution 
  was 
  sprayed 
  on 
  the 
  20th 
  May 
  and 
  

   4 
  per 
  cent, 
  of 
  the 
  larvae 
  were 
  killed. 
  This 
  result 
  is 
  distinctly 
  opposed 
  

   to 
  those 
  of 
  the 
  previous 
  year 
  [see 
  this 
  Revieiv, 
  Ser. 
  A, 
  ii, 
  pp. 
  239-240] 
  

   and 
  further 
  trials 
  are 
  required. 
  The 
  former 
  good 
  result 
  may 
  have 
  

   been 
  due 
  to 
  action 
  against 
  grape-rot 
  and 
  stem-rot 
  (Botrytis) 
  rather 
  

   than 
  against 
  the 
  larvae. 
  The 
  treated 
  vines 
  were 
  slightly 
  scorched 
  

   and 
  growth 
  was 
  retarded. 
  Dr. 
  Ohler's 
  preparation 
  is 
  an 
  emulsion 
  of 
  

   non-poisonous 
  alkalis 
  and 
  oily 
  Hquids 
  (carbonate 
  of 
  soda 
  and 
  turpen- 
  

   tine). 
  Great 
  care 
  is 
  necessary 
  in 
  thoroughly 
  mixing 
  the 
  spray 
  for 
  

   use, 
  or 
  the 
  turpentine 
  may 
  separate. 
  Spraying 
  took 
  place 
  on 
  the 
  

   20th 
  May 
  and 
  28-6 
  per 
  cent, 
  of 
  the 
  larvae 
  were 
  killed. 
  No 
  injury 
  to 
  

   the 
  vines 
  was 
  noticeable, 
  but 
  it 
  is 
  evidently 
  inferior 
  to 
  nicotin. 
  

   " 
  Conchy 
  cid 
  " 
  only 
  destroyed 
  10' 
  3 
  per 
  cent, 
  of 
  the 
  larvae 
  in 
  these 
  

  

  