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  which 
  are 
  very 
  sensitive 
  and 
  are 
  killed 
  by 
  even 
  slightly 
  unfavourable 
  

   conditions. 
  Therefore 
  it 
  is 
  assumed 
  that 
  reploughing 
  in 
  autumn 
  of 
  

   the 
  soil 
  on 
  which 
  summer 
  wheat 
  has 
  been 
  grown 
  must 
  prove 
  effective, 
  

   although 
  this 
  method 
  does 
  not 
  fit 
  in 
  with 
  local 
  economic 
  conditions. 
  

   Early 
  sowing 
  of 
  winter 
  grain 
  and 
  late 
  sowing 
  of 
  the 
  summer 
  crop 
  would 
  

   be 
  very 
  beneficial, 
  but 
  such 
  sowings 
  are 
  proved 
  to 
  be 
  less 
  productive, 
  

   and 
  besides 
  they 
  are 
  more 
  injured 
  by 
  some 
  other 
  pests, 
  such 
  as 
  Oscinis 
  

   frit, 
  Mayetiola 
  destructor, 
  Aphids, 
  etc. 
  

  

  The 
  second 
  pest 
  dealt 
  with 
  is 
  Leptohylemyia 
  coarctata, 
  Fall., 
  and 
  a 
  

   full 
  review 
  of 
  the 
  previous 
  literature 
  concerning 
  this 
  fly 
  is 
  given. 
  The 
  

   author 
  first 
  observed 
  this 
  pest 
  in 
  1912, 
  when 
  two 
  larvae 
  were 
  found 
  

   in 
  May 
  on 
  winter 
  wheat. 
  In 
  1913, 
  the 
  first 
  larvae 
  were 
  discovered 
  on 
  

   rye 
  on 
  the 
  9th 
  April, 
  the 
  rye 
  having 
  been 
  sown 
  on 
  the 
  24th 
  July 
  1912.; 
  

   the 
  last 
  larva 
  was 
  found 
  on 
  the 
  21st 
  May. 
  Experiments 
  have 
  shown 
  

   that 
  the 
  larvae 
  are 
  able 
  to 
  move 
  in 
  the 
  earth 
  from 
  one 
  plant 
  to 
  another, 
  

   in 
  which 
  case 
  they 
  eat 
  into 
  the 
  stalk, 
  sometimes 
  damaging 
  the 
  tillering 
  

   knot 
  and 
  thus 
  causing 
  the 
  plant 
  to 
  perish. 
  The 
  puparia 
  were 
  found, 
  

   in 
  1912, 
  on 
  the 
  5th 
  May 
  in 
  the 
  earth 
  at 
  a 
  depth 
  of 
  2-3J 
  inches, 
  the 
  

   duration 
  of 
  the 
  pupal 
  stage 
  being 
  over 
  seven 
  weeks. 
  In 
  1913, 
  the 
  first 
  

   imago 
  on 
  the 
  Station 
  hatched 
  on 
  8th 
  June, 
  from 
  some 
  rye 
  which 
  had 
  

   been 
  sown 
  in 
  July 
  1912. 
  The 
  maximum 
  emergence 
  took 
  place 
  from 
  

   the 
  20th 
  to 
  22nd 
  June 
  and 
  entirely 
  ceased 
  at 
  the 
  end 
  of 
  that 
  month. 
  

   The 
  number 
  of 
  insects 
  on 
  the 
  wing 
  in 
  the 
  open 
  increased 
  till 
  the 
  

   beginning 
  of 
  July, 
  and 
  they 
  confined 
  themselves 
  to 
  summer 
  wheat 
  

   and 
  to 
  oats. 
  Having 
  dissected 
  the 
  ovaries 
  of 
  some 
  flies, 
  which 
  are 
  

   described 
  and 
  figured, 
  the 
  author 
  came 
  to 
  the 
  conclusion 
  that 
  no 
  

   second 
  summer 
  generation 
  of 
  these 
  flies 
  is 
  produced, 
  as 
  the 
  sexual 
  

   products 
  were 
  not 
  mature 
  by 
  the 
  end 
  of 
  July. 
  A 
  fimgus 
  disease, 
  

   which 
  spread 
  at 
  this 
  time, 
  killed 
  all 
  the 
  flies 
  in 
  the 
  laboratory, 
  save 
  one 
  

   female, 
  which 
  however 
  had 
  an 
  enlarged 
  body 
  from 
  which 
  it 
  was 
  

   assumed 
  that 
  its 
  ovaries 
  were 
  beginning 
  to 
  fill 
  with 
  eggs. 
  This 
  female 
  

   was 
  dissected 
  on 
  the 
  15th 
  September 
  and 
  mature 
  eggs 
  were 
  found 
  in 
  its 
  

   ovaries. 
  Two 
  eggs 
  were 
  found 
  in 
  the 
  box 
  in 
  which 
  it 
  was 
  kept, 
  not 
  

   deep 
  in 
  the 
  earth, 
  and 
  they 
  were 
  quite 
  similar 
  to 
  the 
  eggs 
  contained 
  in 
  

   the 
  ovaries 
  of 
  the 
  female. 
  The 
  author 
  describes 
  and 
  figures 
  the 
  eggs, 
  

   and 
  shows 
  reasons 
  for 
  beheving 
  that 
  the 
  egg 
  is 
  the 
  wintering 
  stage 
  for 
  

   this 
  insect. 
  

  

  In 
  the 
  government 
  of 
  Poltava 
  the 
  damage 
  done 
  by 
  this 
  fly 
  was 
  not 
  

   great, 
  as 
  shown 
  by 
  a 
  table, 
  but 
  at 
  the 
  same 
  time 
  it 
  proved 
  very 
  injurious 
  

   elsewhere, 
  and 
  especially 
  in 
  the 
  governments 
  of 
  Tambov 
  and 
  Voronezh. 
  

   It 
  injures 
  mostly 
  winter-sown 
  crops, 
  such 
  as 
  rye, 
  barley, 
  and 
  wheat 
  ; 
  

   as 
  to 
  summer 
  crops, 
  they 
  are 
  injured 
  only 
  when 
  sown 
  over 
  badly 
  

   infested 
  winter 
  crops. 
  The 
  author 
  is 
  inclined 
  to 
  agree 
  with 
  other 
  

   observers 
  that 
  oviposition 
  takes 
  place 
  preferably 
  on 
  bare 
  fields. 
  

  

  Coming 
  to 
  the 
  question 
  of 
  remedies, 
  the 
  author 
  is 
  of 
  opinion 
  that 
  aU 
  

   the 
  remedies 
  suggested 
  by 
  those 
  who 
  considered 
  erroneously 
  that 
  the 
  

   flies 
  have 
  a 
  summer 
  generation 
  must 
  be 
  excluded. 
  The 
  suggestion 
  

   of 
  Ormerod 
  and 
  Rostrup 
  to 
  dispense 
  with 
  fallow 
  fields 
  and 
  with 
  the 
  

   early 
  sowing 
  of 
  winter 
  grain 
  crops 
  after 
  the 
  previous 
  crop 
  has 
  been 
  

   cleared 
  is 
  not 
  apphcable 
  to 
  either 
  Russia, 
  England 
  or 
  Scandinavia 
  ; 
  

   and 
  in 
  any 
  case 
  further 
  experiments 
  are 
  needed 
  in 
  order 
  to 
  arrive 
  at 
  

   the 
  best 
  possible 
  combination. 
  It 
  is 
  recommended 
  to 
  manure 
  the 
  

   winter-sown 
  fields 
  with 
  nitrates 
  after 
  the 
  thawing 
  of 
  the 
  snow, 
  when 
  

  

  