﻿SCALE 
  INSECTS 
  OF 
  IMPORTANCE 
  339 
  

  

  35° 
  was 
  almost 
  uniformly 
  fatal. 
  A 
  safe 
  petroleum, 
  he 
  states, 
  must 
  be 
  

   either 
  a 
  green 
  or 
  an 
  amber 
  colored 
  paraffin 
  oil, 
  not 
  an 
  asphaltum 
  oil. 
  

   There 
  is 
  still 
  need 
  of 
  more 
  experiments 
  along 
  this 
  line 
  and 
  of 
  a 
  clearer 
  

   understanding 
  of 
  just 
  what 
  is 
  meant 
  by 
  crude 
  oil 
  before 
  the 
  use 
  of 
  undi- 
  

   luted 
  petroleum 
  can 
  be 
  advised 
  in 
  this 
  state. 
  

  

  Kerosene. 
  Spraying 
  trees 
  in. 
  early 
  spring 
  with 
  ordinary 
  undiluted 
  

   kerosene 
  did 
  not 
  result 
  in 
  nearly 
  so 
  thorough 
  work 
  as 
  a 
  20% 
  crude 
  

   petroleum 
  emulsion, 
  and 
  it 
  was 
  much 
  more 
  injurious 
  to 
  the 
  trees. 
  Its 
  

   use 
  can 
  not 
  be 
  advised. 
  

  

  Kerosene 
  emulsion. 
  A 
  mechanical 
  io% 
  kerosene 
  emulsion 
  is 
  a 
  

   most 
  excellent 
  summer 
  spray 
  to 
  be 
  applied 
  when 
  the 
  young 
  scale 
  insects 
  

   are 
  numerous, 
  and 
  it 
  has 
  proved 
  harmless 
  to 
  the 
  trees. 
  H. 
  P. 
  Gould 
  has 
  

   used 
  a 
  20% 
  mechanical 
  emulsion 
  in 
  summer 
  without 
  harming 
  the 
  trees 
  

   to 
  an 
  appreciable 
  extent, 
  but 
  as 
  the 
  lower 
  per 
  cent 
  of 
  oil 
  gives 
  very 
  satisfac- 
  

   tory 
  results, 
  there 
  is 
  no 
  necessity 
  of 
  using 
  more. 
  Early 
  June 
  appH- 
  

   cations 
  would 
  probably 
  prove 
  very 
  effective 
  against 
  appletree 
  and 
  scurfy 
  

   bark 
  lice. 
  The 
  20% 
  and 
  25% 
  mechanical 
  emulsions 
  appHed 
  in 
  early 
  

   spring 
  just 
  before 
  the 
  buds 
  started, 
  failed 
  to 
  kill 
  many 
  scale 
  insects, 
  and 
  

   its 
  use 
  is 
  not 
  recommended 
  at 
  this 
  time. 
  

  

  Other 
  summer 
  sprays. 
  The 
  ordinary 
  kerosene 
  emulsion 
  may 
  be 
  

   prepared 
  by 
  taking 
  i^ 
  pounds 
  of 
  hard 
  soap, 
  i 
  gallon 
  of 
  boiling 
  water 
  

   and 
  2 
  gallons 
  of 
  kerosene. 
  Dissolve 
  the 
  soap 
  in 
  the 
  water, 
  add 
  the 
  

   kerosene 
  and 
  then 
  agitate 
  the 
  mixture 
  vigorously 
  by 
  stirring 
  or 
  by 
  repeat- 
  

   edly 
  passing 
  it 
  through 
  a 
  force 
  pump 
  with 
  a 
  nozzle 
  attached, 
  till 
  an 
  

   emulsion 
  of 
  creamy 
  consistency 
  is 
  obtained, 
  and 
  oil 
  does 
  not 
  rise 
  to 
  the 
  

   surface. 
  For 
  summer 
  work 
  against 
  the 
  San 
  Jose 
  scale 
  this 
  may 
  be 
  

   diluted 
  with 
  9 
  parts 
  of 
  water, 
  i 
  pound 
  of 
  whale 
  oil 
  soap 
  dissolved 
  in 
  

   5 
  gallons 
  of 
  water 
  may 
  be 
  used 
  in 
  a 
  similar 
  manner 
  without 
  injury 
  to 
  the 
  

   trees. 
  The 
  sour 
  milk 
  emulsion, 
  which 
  is 
  simply 
  2 
  gallons 
  of 
  kerosene 
  and 
  

   I 
  gallon 
  of 
  sour 
  milk, 
  emulsified 
  and 
  diluted 
  as 
  described 
  above, 
  is 
  pref- 
  

   erable 
  for 
  limestone 
  regions 
  or 
  where 
  soft 
  water 
  can 
  not 
  be 
  obtained 
  

   readily. 
  These 
  summer 
  sprays 
  are 
  of 
  service 
  only 
  in 
  checking 
  the 
  San 
  

   Jose 
  scale, 
  if 
  previous 
  applications 
  have 
  for 
  some 
  reason 
  proven 
  unsatis- 
  

   factory. 
  They 
  are 
  very 
  efficient 
  when 
  used 
  against 
  appletree 
  and 
  scurfy 
  

   bark 
  hce. 
  

  

  Fumigation 
  in 
  orchards. 
  Treatment 
  of 
  pernicious, 
  or 
  San 
  Jose 
  

   scale 
  with 
  hydrocyanic 
  acid 
  gas 
  gave 
  most 
  excellent 
  results 
  on 
  small 
  

   trees 
  in 
  an 
  orchard. 
  Unfortunately 
  it 
  involves 
  the 
  use 
  of 
  costly 
  tents, 
  

   specially 
  for 
  large 
  trees. 
  It 
  is 
  admirably 
  adapted 
  for 
  large 
  orchards 
  of 
  

  

  