﻿THE 
  CHERRY 
  FRUIT 
  SAWFLY. 
  79 
  

  

  material. 
  It 
  is 
  possible 
  that 
  this 
  species 
  is 
  rather 
  heavily 
  para- 
  

   sitized 
  at 
  times. 
  The 
  insect 
  has 
  been 
  known 
  in 
  the 
  Suisun 
  Valley 
  

   since 
  1905, 
  but 
  caused 
  comparatively 
  little 
  injury 
  from 
  that 
  time 
  

   until 
  the 
  serious 
  outbreak 
  of 
  1909. 
  As 
  no 
  spraying 
  had 
  been 
  done 
  

   in 
  the 
  infested 
  orchards 
  that 
  would 
  be 
  of 
  any 
  value 
  as 
  a 
  control 
  to 
  

   this 
  particular 
  species 
  it 
  would 
  seem 
  that 
  the 
  parasites, 
  together 
  with 
  

   more 
  thorough 
  cultivation, 
  have 
  served 
  to 
  keep 
  it 
  fairly 
  well 
  in 
  check. 
  

   The 
  insect 
  was 
  less 
  numerous 
  in 
  1910 
  than 
  in 
  1909 
  and 
  the 
  same 
  was 
  

   true 
  of 
  the 
  years 
  1911 
  and 
  1912. 
  

  

  EXPERIMENTS 
  IN 
  CONTROL. 
  

  

  Experiments 
  in 
  spraying 
  with 
  arsenate 
  of 
  lead 
  were 
  made 
  in 
  1910, 
  

   but 
  in 
  this 
  instance 
  the 
  poison 
  did 
  not 
  prove 
  to 
  be 
  altogether 
  effec- 
  

   tive. 
  Some 
  larvae 
  were 
  killed, 
  but 
  not 
  enough 
  to 
  warrant 
  the 
  recom- 
  

   mendation 
  of 
  this 
  as 
  a 
  satisfactory 
  treatment 
  in 
  case 
  of 
  a 
  serious 
  out- 
  

   break 
  of 
  the 
  insect. 
  Further 
  work 
  along 
  this 
  line 
  is 
  desirable. 
  Mr. 
  

   O'Gara, 
  in 
  a 
  letter, 
  reports 
  satisfactory 
  results 
  from 
  the 
  use 
  of 
  arse- 
  

   nate 
  of 
  lead 
  in 
  the 
  Rogue 
  River 
  Valley 
  of 
  Oregon. 
  

  

  Many 
  adults 
  were 
  killed 
  in 
  the 
  early 
  mornings 
  while 
  spraying 
  with 
  

   3 
  per 
  cent 
  distillate-oil 
  emulsion 
  to 
  which 
  sulphate 
  of 
  nicotine 
  had 
  

   been 
  added 
  at 
  the 
  rate 
  of 
  1 
  part 
  to 
  2,000 
  parts 
  of 
  water. 
  This 
  

   method 
  would 
  most 
  likely 
  be 
  a 
  very 
  effective 
  means 
  of 
  control 
  if 
  all 
  

   the 
  spraying 
  could 
  be 
  done 
  in 
  the 
  early 
  morning. 
  At 
  this 
  time 
  the 
  

   adults 
  are 
  very 
  sluggish 
  and 
  can 
  be 
  easily 
  wet 
  with 
  the 
  spray. 
  

  

  Perhaps 
  a 
  more 
  likely 
  means 
  of 
  holding 
  this 
  sawfly 
  in 
  check 
  is 
  by 
  

   careful 
  cultivation. 
  The 
  most 
  serious 
  hindrance 
  to 
  this 
  plan 
  of 
  

   treatment 
  in 
  cherry 
  orchards 
  is 
  that 
  the 
  roots 
  of 
  the 
  cherry 
  tree 
  close 
  

   to 
  the 
  trunk 
  are 
  near 
  the 
  surface, 
  and 
  some 
  larvae 
  go 
  below 
  the 
  top 
  of 
  

   these 
  roots. 
  However, 
  it 
  is 
  highly 
  advisable 
  to 
  cultivate 
  the 
  land 
  

   thoroughly 
  two 
  or 
  three 
  times 
  just 
  prior 
  to 
  the 
  first 
  picking 
  of 
  the 
  

   Black 
  Tartarian 
  cherries, 
  as 
  most 
  of 
  the 
  larvae 
  are 
  leaving 
  the 
  trees 
  

   at 
  this 
  time 
  and 
  numbers 
  of 
  them 
  would 
  probably 
  be 
  killed. 
  

  

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