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  where 
  a 
  number 
  of 
  vineyards 
  are 
  situated 
  together 
  and 
  their 
  

   respective 
  owners 
  agree 
  to 
  practise 
  control. 
  In 
  the 
  case 
  of 
  Clysia 
  and 
  

   Polychrosis, 
  the 
  traps 
  must 
  be 
  placed 
  on 
  the 
  vine 
  stocks 
  in 
  order 
  to 
  stop 
  

   the 
  caterpillars 
  before 
  they 
  can 
  reach 
  the 
  bark 
  of 
  the 
  old 
  wood. 
  Another 
  

   method 
  in 
  favour 
  in 
  South 
  Tyrol, 
  consists 
  of 
  wrapping 
  strips 
  of 
  cloth, 
  

   10 
  to 
  12 
  inches 
  long 
  by 
  4 
  to 
  5 
  inches 
  wide, 
  at 
  the 
  base 
  of 
  the 
  

   branches 
  and 
  on 
  two-year-old 
  wood. 
  The 
  quality 
  of 
  the 
  cloth 
  

   is 
  immaterial 
  provided 
  it 
  is 
  odourless. 
  This 
  method 
  is 
  valuable 
  

   because 
  it 
  permits 
  the 
  destruction 
  of 
  a 
  large 
  number 
  of 
  Clysia 
  

   and 
  Polychrosis 
  pupae, 
  but 
  spares 
  their 
  parasites 
  to 
  a 
  certain 
  

   extent. 
  The 
  proper 
  time 
  to 
  remove 
  these 
  traps 
  vnW 
  be 
  indicated 
  

   by 
  the 
  moths 
  themselves. 
  A 
  too 
  early 
  removal 
  will 
  entail 
  the 
  

   destruction 
  of 
  the 
  useful 
  parasites 
  and 
  one 
  that 
  is 
  too 
  long 
  delayed 
  

   will 
  permit 
  the 
  moths 
  to 
  emerge. 
  The 
  best 
  system 
  is 
  to 
  inspect 
  daily 
  

   those 
  traps 
  which 
  are 
  in 
  sunny 
  situations, 
  protected 
  against 
  mnd. 
  

   When 
  the 
  first 
  moths 
  appear 
  all 
  the 
  useful 
  insects 
  will 
  have 
  left 
  the 
  

   traps. 
  The 
  strips 
  must 
  be 
  placed 
  in 
  position 
  before 
  the 
  caterpillars 
  

   of 
  the 
  second 
  generation 
  (Clysia) 
  or 
  of 
  the 
  third 
  generation 
  (Polychrosis) 
  

   have 
  reached 
  the 
  adult 
  state. 
  Such 
  traps 
  are 
  also 
  useful 
  against 
  

   Sparganothis 
  and, 
  in 
  this 
  case, 
  should 
  be 
  used 
  much 
  earlier, 
  usually 
  early 
  

   in 
  August. 
  If 
  properly 
  executed, 
  decortication 
  is 
  a 
  certain 
  remedy, 
  

   but 
  it 
  must 
  be 
  complete, 
  and 
  the 
  work 
  must 
  be 
  done 
  in 
  mid- 
  winter 
  and 
  

   after 
  pruning, 
  the 
  debris 
  being 
  collected 
  and 
  burnt. 
  Care 
  must 
  be 
  

   taken 
  not 
  to 
  touch 
  the 
  young 
  bark 
  still 
  adhering 
  to 
  the 
  trunk. 
  The 
  

   cost 
  works 
  out 
  at 
  about 
  22s. 
  per 
  acre 
  or 
  less, 
  according 
  to 
  the 
  number 
  

   of 
  stocks. 
  This 
  is 
  not 
  expensive 
  when 
  it 
  is 
  remembered 
  that 
  the 
  effects 
  

   last 
  for 
  3 
  or 
  4 
  years 
  and 
  also 
  involves 
  the 
  destruction 
  of 
  scale- 
  insects. 
  

   The 
  work 
  is 
  rendered 
  much 
  easier 
  if 
  a 
  10 
  per 
  cent, 
  solution 
  of 
  sulphuric 
  

   acid 
  be 
  apphed 
  to 
  the 
  stocks, 
  as 
  the 
  bark 
  is 
  then 
  more 
  easily 
  removable. 
  

   The 
  gravest 
  objection 
  to 
  decortication 
  is 
  that 
  the 
  stripping 
  off 
  of 
  the 
  

   bark 
  leaves 
  the 
  vines 
  ill-protected 
  against 
  the 
  cold. 
  Sluicing 
  with 
  

   hot 
  w^ater, 
  when 
  applied 
  immediately 
  after 
  the 
  grape 
  harvest, 
  appears 
  

   to 
  kill 
  a 
  large 
  number 
  of 
  Clysia 
  caterpillars. 
  In 
  1900, 
  Laborde 
  

   ascertained 
  that 
  Clysia 
  pupae 
  in 
  their 
  cocoons 
  are 
  destroyed 
  by 
  a 
  

   temperature 
  of 
  131° 
  Fahr. 
  maintained 
  for 
  15 
  seconds. 
  With 
  Polychrosis 
  

   pupae, 
  Feytaud 
  and 
  Capus 
  found 
  that 
  1 
  minute 
  at 
  113°-122° 
  Fahr., 
  

   30 
  seconds 
  at 
  128° 
  Fahr., 
  and 
  20 
  seconds 
  at 
  131° 
  Fahr., 
  are 
  sufficient 
  to 
  

   cause 
  death, 
  which 
  is 
  instantaneous 
  at 
  158° 
  Fahr. 
  The 
  experiments 
  

   conducted 
  at 
  the 
  Montpellier 
  school 
  by 
  G. 
  Verge 
  during 
  the 
  winter 
  

   of 
  1910-11 
  are 
  most 
  valuable 
  from 
  a 
  practical 
  point 
  of 
  view. 
  The 
  

   water 
  is 
  taken 
  at 
  a 
  temperature 
  of 
  212° 
  Fahr. 
  from 
  an 
  ordinary 
  

   boiler 
  and 
  put 
  into 
  a 
  container 
  of 
  14 
  J 
  pints 
  capacity 
  for 
  distribution 
  

   purposes. 
  This 
  container 
  stands 
  on 
  a 
  tripod 
  and 
  is 
  fitted 
  mth 
  a 
  heater 
  

   which 
  maintains 
  the 
  temperature 
  nearly 
  at 
  boihng 
  point, 
  so 
  that 
  the 
  

   water 
  reaches 
  the 
  vine-stock 
  at 
  about 
  that 
  degree 
  of 
  heat. 
  Careful 
  

   thermometric 
  measurements 
  prove 
  that 
  the 
  water 
  penetrates 
  to 
  the 
  

   deepest 
  bark 
  at 
  198° 
  Fahr. 
  Two 
  plots, 
  each 
  containing 
  12 
  stocks, 
  were 
  

   used 
  in 
  the 
  test. 
  In 
  the 
  first, 
  each 
  stock 
  was 
  treated 
  with 
  2| 
  pints 
  of 
  

   water 
  and 
  a 
  mortality 
  of 
  87 
  per 
  cent, 
  resulted, 
  95 
  pupae 
  being 
  killed 
  

   out 
  of 
  109. 
  In 
  the 
  second, 
  4 
  pints 
  were 
  applied 
  and 
  the 
  mortality 
  

   reached 
  97 
  per 
  cent., 
  99 
  pupae 
  dying 
  out 
  of 
  103. 
  In 
  the 
  laboratory 
  

   experiments 
  referred 
  to 
  above, 
  Laborde 
  obtained 
  a 
  percentage 
  of 
  77 
  

   to 
  100 
  and 
  Feytaud, 
  80 
  to 
  88. 
  At 
  the 
  time 
  of 
  Verge's 
  test 
  (the 
  23rd 
  of 
  

  

  