﻿626 
  

  

  cause 
  a 
  loss 
  of 
  35 
  per 
  cent, 
  or 
  even 
  50 
  per 
  cent, 
  of 
  the 
  vintage, 
  and 
  

   vineyards 
  which 
  some 
  years 
  ago 
  yielded 
  from 
  3J 
  to 
  6 
  tons 
  per 
  acre 
  now 
  

   only 
  yield 
  from 
  2 
  J 
  to 
  3 
  tons. 
  

  

  Polychrosis 
  botrana, 
  which 
  has 
  been 
  known 
  in 
  the 
  vineyards 
  since 
  

   1865, 
  is 
  the 
  cause 
  of 
  considerable 
  damage, 
  amounting 
  in 
  1902 
  to 
  over 
  

   £30,000. 
  Control 
  measures 
  against 
  this 
  pest 
  in 
  Astrachan 
  consisted 
  

   in 
  the 
  removal 
  of 
  the 
  damaged 
  grapes 
  during 
  June 
  and 
  July 
  and 
  again 
  

   during 
  the 
  vintage, 
  these 
  periods 
  corresponding 
  with 
  the 
  presence 
  of 
  

   the 
  two 
  generations 
  of 
  caterpillars. 
  Laborde 
  considered 
  spraying 
  with 
  

   Paris 
  green 
  to 
  be 
  as 
  injurious 
  to 
  the 
  vines 
  as 
  to 
  the 
  caterpillars, 
  and 
  

   suggested 
  spraying 
  with 
  substances 
  which 
  form 
  a 
  varnish 
  over 
  the 
  

   vine 
  clusters 
  and 
  thus 
  suffocate 
  the 
  insects 
  in 
  all 
  their 
  stages. 
  Among 
  

   other 
  remedies 
  he 
  recommended 
  : 
  — 
  Catching 
  the 
  moths 
  early 
  in 
  May 
  

   and 
  again 
  in 
  the 
  first 
  half 
  of 
  July 
  by 
  means 
  of 
  special 
  lamps, 
  

   surrounded 
  by 
  tins 
  filled 
  with 
  water, 
  and 
  washing 
  or 
  spraying 
  

   branches 
  after 
  the 
  vintage 
  with 
  water 
  at 
  a 
  temperature 
  of 
  80° 
  C. 
  

   (176° 
  F.), 
  care 
  being 
  taken 
  not 
  to 
  damage 
  the 
  *' 
  eyes 
  " 
  of 
  the 
  yearling 
  

   shoots 
  and 
  directing 
  the 
  water 
  principally 
  on 
  to 
  the 
  bark 
  of 
  the 
  old 
  

   wood 
  as 
  well 
  as 
  over 
  the 
  supporting 
  stakes, 
  in 
  the 
  cracks 
  of 
  which 
  

   the 
  cocoons 
  are 
  mostly 
  found. 
  

  

  In 
  1903, 
  and 
  again 
  in 
  1910, 
  the 
  Board 
  of 
  Agriculture 
  sent 
  Y. 
  F. 
  

   Schreiner 
  specially 
  to 
  Astrachan, 
  and 
  he 
  was 
  of 
  opinion 
  that 
  

   Polychrosis 
  botrana 
  destroys 
  not 
  less 
  than 
  one-third 
  of 
  the 
  yearly 
  vintage 
  

   in 
  that 
  region, 
  and 
  occurs 
  there 
  in 
  three 
  generations 
  ; 
  the 
  first 
  one 
  living 
  

   on 
  weeds, 
  the 
  second 
  on 
  the 
  green 
  grapes, 
  and 
  the 
  third 
  on 
  the 
  

   ripening 
  grapes. 
  Measures 
  must 
  be 
  directed 
  in 
  the 
  first 
  instance 
  against 
  

   the 
  first 
  generation, 
  against 
  which 
  he 
  recommended 
  spraying 
  with 
  

   Paris 
  green 
  and 
  lime 
  (2J 
  oz. 
  of 
  green 
  and 
  about 
  1 
  oz. 
  of 
  freshly 
  slaked, 
  

   fat 
  lime 
  in 
  8 
  gallons 
  of 
  water), 
  to 
  which 
  some 
  rye 
  paste 
  (about 
  10 
  oz. 
  

   to 
  every 
  7 
  gallons 
  of 
  water) 
  is 
  added 
  to 
  make 
  the 
  mixture 
  adhesive. 
  

   The 
  first 
  spraying 
  must 
  be 
  done 
  in 
  May, 
  immediately 
  after 
  the 
  white 
  

   webs 
  connecting 
  the 
  buds 
  of 
  the 
  inflorescence 
  indicate 
  the 
  presence 
  

   of 
  the 
  young 
  larvae. 
  Two 
  more 
  spra5rings 
  at 
  intervals 
  of 
  5 
  to 
  6 
  days 
  

   are 
  necessary 
  in 
  order 
  to 
  reduce 
  the 
  numbers 
  to 
  a 
  minimum 
  and 
  thus 
  

   prevent 
  an 
  outbreak 
  of 
  the 
  second 
  generation. 
  If 
  necessary, 
  the 
  same 
  

   insecticide 
  can 
  be 
  appHed 
  in 
  June, 
  also 
  in 
  three 
  sprayings. 
  Schreiner 
  

   pointed 
  out 
  that 
  scorching 
  with 
  Paris 
  green 
  is 
  not 
  possible 
  when 
  the 
  

   insecticide 
  is 
  prepared 
  with 
  fat, 
  lump 
  hme, 
  slaked 
  just 
  before 
  the 
  

   mixing 
  takes 
  place 
  ; 
  he 
  has 
  also 
  apphed 
  Paris 
  green 
  with 
  salammoniac 
  

   (1| 
  oz. 
  of 
  green 
  are 
  dissolved 
  in 
  a 
  small 
  amount 
  of 
  salammoniac 
  

   and 
  added 
  to 
  27 
  gallons 
  of 
  water) 
  and 
  another 
  insecticide 
  (consisting 
  

   of 
  1^ 
  oz. 
  of 
  white 
  arsenic 
  in 
  powder 
  and 
  double 
  that 
  amount 
  of 
  

   freshly 
  slaked 
  lime 
  boiled 
  together 
  for 
  15 
  to 
  20 
  minutes 
  in 
  27 
  gallons 
  

   of 
  water) 
  for 
  spraying 
  fruit 
  trees, 
  but 
  has 
  not 
  tried 
  the 
  effect 
  of 
  either 
  

   of 
  these 
  insecticides 
  on 
  vines, 
  and 
  was 
  therefore 
  unable 
  to 
  recommend 
  

   them. 
  It 
  might 
  be 
  admissible, 
  instead 
  of 
  spraying, 
  to 
  dip 
  the 
  branches 
  

   in 
  the 
  insecticides, 
  although 
  this 
  method 
  is 
  less 
  practicable. 
  Vine- 
  

   growers 
  are 
  warned 
  against 
  the 
  use 
  of 
  trap 
  lamps, 
  as 
  the 
  insects 
  are 
  

   attracted 
  only 
  to 
  the 
  spaces 
  illuminated 
  by 
  the 
  hght, 
  but 
  not 
  to 
  the 
  

   hghts 
  themselves 
  nor 
  into 
  the 
  water 
  surrounding 
  them. 
  

  

  In 
  1912, 
  Polychrosis 
  botrana 
  appeared 
  in 
  nearly 
  all 
  the 
  vineyards 
  of 
  

   Astrachan, 
  and 
  as 
  much 
  as 
  75 
  per 
  cent, 
  of 
  the 
  grapes 
  in 
  some 
  cases 
  

   were 
  infested. 
  Hitherto 
  no 
  radical 
  remedy 
  against 
  these 
  pests 
  has 
  

  

  