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  discoloured 
  and 
  then 
  the 
  ends 
  dried 
  off. 
  The 
  plants 
  would 
  not 
  grow 
  

   and 
  the 
  attack 
  of 
  the 
  Thrips 
  reduced 
  the 
  harvest 
  by 
  50 
  per 
  cent. 
  The 
  

   insects 
  persist 
  through 
  winter 
  generally 
  on 
  stray 
  plants 
  or 
  under 
  dead 
  

   leaves. 
  The 
  time 
  taken 
  for 
  the 
  complete 
  transformation 
  varies 
  

   greatly 
  according 
  to 
  conditions, 
  the 
  insects 
  observed 
  by 
  Lindeman 
  in 
  

   Bessarabia 
  taking 
  47 
  days, 
  while 
  those 
  bred 
  by 
  Quaintance 
  in 
  Florida 
  

   took 
  only 
  17 
  days. 
  Most 
  authorities 
  consider 
  that 
  the 
  multiplication 
  

   of 
  Thrips 
  tahaci 
  is 
  favoured 
  by 
  drought 
  and 
  seriously 
  hindered 
  by 
  rain. 
  

   The 
  author 
  however 
  is 
  of 
  the 
  opinion 
  that 
  moisture 
  is 
  not 
  really 
  

   unfavourable 
  to 
  this 
  insect, 
  but 
  rather 
  that 
  drought 
  weakens 
  the 
  

   plants 
  and 
  diminishes 
  their 
  resisting 
  power. 
  Fields 
  are 
  often 
  invaded 
  

   by 
  Thrips 
  which 
  have 
  hibernated 
  and 
  developed 
  on 
  wild 
  plants. 
  The 
  

   destruction 
  of 
  such 
  vegetation 
  on 
  the 
  borders 
  of 
  fields 
  w^ould 
  therefore 
  

   be 
  a 
  preventive 
  measure, 
  especially 
  if 
  it 
  be 
  burnt 
  during 
  the 
  winter. 
  In 
  

   order 
  to 
  counteract 
  the 
  effect 
  of 
  drought 
  and 
  allow 
  the 
  plants 
  to 
  

   resist 
  effectively 
  the 
  attacks 
  of 
  the 
  insect, 
  irrigation 
  should 
  be 
  employed 
  

   where 
  possible. 
  Most 
  contact 
  insecticides 
  are 
  effective 
  against 
  this 
  

   Thrips, 
  but 
  unfortunately 
  the 
  insects 
  are 
  difficult 
  to 
  reach 
  since 
  they 
  

   occur 
  in 
  the 
  folds 
  of 
  the 
  leaves. 
  A 
  simple 
  3 
  per 
  cent, 
  soap 
  solution 
  is 
  

   effective 
  in 
  most 
  cases. 
  

  

  Hollo 
  WAY 
  (T. 
  E.). 
  The 
  Prospect 
  of 
  controlling 
  the 
  Sugar-Cane 
  Borer 
  

   more 
  efficiently. 
  — 
  Louisiana 
  Planter 
  and 
  Sugar 
  Manufacturer, 
  New 
  

   Orleans, 
  La., 
  li, 
  no. 
  25. 
  20th 
  Dec. 
  1913, 
  p. 
  416, 
  3 
  figs. 
  [Reed. 
  

   30th 
  March 
  1914.] 
  

  

  Experiments 
  on 
  the 
  control 
  of 
  the 
  sugar-cane 
  moth 
  {Diatraea 
  

   saccharalis) 
  have 
  been 
  extraordinarily 
  successful. 
  On 
  the 
  Piper 
  

   plantation, 
  Texas, 
  no 
  cane 
  trash 
  was 
  burned 
  in 
  the 
  autumn 
  and 
  winter 
  

   of 
  1912-13, 
  but 
  it 
  was 
  all 
  ploughed 
  under 
  in 
  the 
  spring 
  of 
  1913. 
  On 
  

   the 
  neighbouring 
  plantations 
  the 
  trash 
  was 
  burned 
  in 
  the 
  autumn 
  as 
  

   usual. 
  On 
  examination 
  it 
  was 
  found 
  that 
  the 
  average 
  infestation 
  

   of 
  the 
  unburned 
  fields 
  was 
  30"6 
  per 
  cent., 
  while 
  that 
  of 
  the 
  burned 
  

   fields 
  was 
  76 
  per 
  cent. 
  In 
  1912, 
  the 
  average 
  infestation 
  of 
  the 
  burned 
  

   fields 
  was 
  50*5 
  per 
  cent, 
  and 
  a 
  few^ 
  miles 
  away 
  86 
  per 
  cent. 
  Burning 
  

   over 
  a 
  field 
  is 
  the 
  obvious 
  method 
  of 
  controlhng 
  an 
  insect 
  pest 
  in 
  certain 
  

   cases, 
  but 
  the 
  sugar-cane 
  field 
  presents 
  a 
  different 
  problem. 
  The 
  

   borers 
  stay 
  in 
  the 
  stalks 
  and 
  when 
  the 
  stalks 
  are 
  passed 
  through 
  the 
  

   mill 
  the 
  borers 
  are 
  killed. 
  On 
  the 
  field 
  are 
  left 
  a 
  few 
  borers 
  in 
  the 
  

   tops, 
  and 
  probably 
  more 
  in 
  the 
  stubble, 
  and 
  egg-parasites 
  on 
  the 
  

   leaves 
  and 
  in 
  the 
  egg-masses 
  of 
  the 
  borers 
  which 
  are 
  attached 
  to 
  the 
  

   leaves. 
  If 
  the 
  leaves 
  are 
  burned, 
  many 
  parasites 
  are 
  killed 
  and 
  only 
  

   a 
  few 
  borers. 
  When 
  the 
  cane 
  begins 
  to 
  grow 
  next 
  season, 
  the 
  borers 
  

   come 
  up 
  from 
  the 
  stubble, 
  and 
  very 
  few 
  parasites 
  are 
  then 
  present 
  

   to 
  control 
  them. 
  These 
  parasites 
  are 
  very 
  valuable 
  in 
  destroying 
  

   the 
  eggs 
  of 
  many 
  other 
  moths 
  besides 
  those 
  of 
  the 
  sugar-cane 
  moth 
  

   and 
  should 
  in 
  no 
  way 
  be 
  destroyed. 
  From 
  these 
  experiments 
  the 
  

   author 
  is 
  of 
  opinion 
  that 
  the 
  disposal 
  of 
  the 
  trash 
  by 
  ploughing 
  under 
  

   will 
  give 
  the 
  most 
  satisfactory 
  results, 
  though 
  he 
  notes 
  that 
  the 
  plan 
  

   of 
  raking 
  the 
  trash 
  to 
  the 
  headlands, 
  as 
  done 
  by 
  Mr. 
  Taggart 
  at 
  

   Audubon 
  Park, 
  resulted 
  in 
  a 
  greater 
  reduction 
  in 
  the 
  percentage 
  of 
  

   infestation 
  than 
  was 
  accomplished 
  by 
  ploughing 
  the 
  trash 
  under 
  in 
  

   the 
  spring 
  in 
  Texas. 
  

  

  