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  distinguishing 
  it 
  from 
  the 
  San 
  Jose 
  scale. 
  The 
  oyster-shell 
  

   scale 
  passes 
  the 
  winter 
  in 
  the 
  egg 
  stage, 
  the 
  eggs 
  hatching 
  

   about 
  1st 
  June. 
  There 
  is 
  only 
  one 
  brood 
  a 
  year 
  in 
  Ontario. 
  

   The 
  chief 
  means 
  of 
  distribution 
  of 
  this 
  insect 
  is 
  the 
  shipment 
  of 
  

   infested 
  nursery 
  stock, 
  as 
  well 
  as 
  the 
  carrying 
  of 
  the 
  larvae 
  by 
  birds 
  

   and 
  other 
  animals. 
  Among 
  the 
  natural 
  enemies 
  of 
  this 
  pest 
  are 
  lady- 
  

   bird 
  beetles 
  (adults 
  and 
  larvae), 
  a 
  few 
  mites 
  and 
  a 
  fungus 
  disease. 
  

   The 
  lime-sulphur 
  wash, 
  properly 
  appHed, 
  will 
  readily 
  control 
  this 
  

   scale. 
  Two 
  sprayings 
  should 
  be 
  given 
  for 
  the 
  best 
  results, 
  the 
  first 
  

   at 
  the 
  strength 
  of 
  1 
  "030 
  and 
  the 
  second 
  at 
  1 
  '009 
  specific 
  gravity. 
  The 
  

   spray 
  not 
  only 
  destroys 
  the 
  oyster-shell 
  scale, 
  but 
  many 
  other 
  insects. 
  

   Bordeaux 
  mixture 
  may 
  be 
  used 
  in 
  place 
  of 
  the 
  lime-sulphur, 
  just 
  before 
  

   the 
  blossoms 
  burst. 
  Old 
  trees 
  should 
  be 
  pruned 
  before 
  spraying 
  and 
  

   the 
  rough 
  bark 
  scraped 
  off. 
  

  

  OouGH 
  (L. 
  H.) 
  & 
  Storey 
  (G.). 
  Methods 
  for 
  the 
  Destruction 
  of 
  the 
  

   Pink 
  Boll 
  Worm 
  in 
  Cotton 
  Seed. 
  — 
  Ministry 
  Agric, 
  Egypt, 
  Cairo, 
  

   1914, 
  21 
  pp. 
  

  

  The 
  history 
  of 
  the 
  pink 
  boll 
  worm 
  in 
  Egypt 
  has 
  been 
  a 
  short, 
  but 
  

   disastrous 
  one. 
  The 
  moth 
  (Gelechia 
  gossypiella, 
  Saund.) 
  was 
  intro- 
  

   duced 
  from 
  abroad 
  not 
  many 
  years 
  ago. 
  The 
  first 
  specimens 
  recorded 
  

   by 
  the 
  Entomological 
  Section 
  were 
  bred 
  on 
  29th 
  November 
  1911, 
  and 
  

   in 
  1913 
  Gelechia 
  larvae 
  caused 
  more 
  damage 
  than 
  all 
  the 
  other 
  cotton 
  

   pests 
  put 
  together. 
  In 
  1912 
  experiments 
  to 
  destroy 
  the 
  caterpillars 
  

   by 
  fumigation 
  were 
  all 
  carried 
  out 
  on 
  seeds 
  in 
  sacks, 
  but 
  the 
  method 
  

   was 
  recognised 
  as 
  very 
  imperfect. 
  In 
  1913 
  other 
  experiments 
  were 
  

   made 
  and 
  the 
  methods 
  may 
  be 
  classed 
  into 
  mechanical 
  and 
  chemical. 
  

   The 
  mechanical 
  methods 
  included 
  hot 
  water 
  treatment, 
  cold 
  air 
  treat- 
  

   ment, 
  hot 
  air 
  treatment, 
  and 
  enclosure 
  in 
  a 
  vacuum. 
  In 
  the 
  experi- 
  

   ments 
  on 
  the 
  first 
  method, 
  small 
  equal 
  quantities 
  of 
  seeds 
  were 
  tied 
  

   up 
  in 
  mushn 
  bags 
  and 
  immersed 
  in 
  beakers 
  of 
  hot 
  water 
  for 
  one 
  minute, 
  

   the 
  temperature 
  being 
  recorded 
  by 
  a 
  thermometer 
  in 
  the 
  water 
  and 
  

   another 
  with 
  its 
  bulb 
  within 
  the 
  seeds. 
  From 
  experiments 
  it 
  is 
  

   shown 
  that 
  the 
  fatal 
  temperature 
  for 
  Gelechia 
  larvae 
  must 
  lie 
  very 
  

   close 
  to 
  50° 
  C, 
  while 
  the 
  fatal 
  temperature 
  for 
  cotton 
  seed 
  is 
  very 
  near 
  

   75°. 
  This 
  is 
  not 
  a 
  suitable 
  method 
  for 
  employment 
  on 
  a 
  large 
  scale 
  

   on 
  account 
  of 
  the 
  necessity 
  for 
  the 
  immediate 
  sowing 
  or 
  immediate 
  

   drying 
  of 
  the 
  tested 
  seed. 
  An 
  experiment 
  was 
  made 
  with 
  tempera- 
  

   tures 
  under 
  0°, 
  and 
  -6° 
  C. 
  was 
  found 
  to 
  have 
  no 
  effect 
  on 
  the 
  larvae. 
  

   Experiments 
  on 
  the 
  effect 
  of 
  temperatures 
  over 
  60° 
  C. 
  gave 
  positive 
  

   results. 
  In 
  the 
  first 
  series 
  a 
  hot 
  water 
  bath 
  was 
  constructed 
  and 
  

   traversed 
  from 
  end 
  to 
  end 
  by 
  a 
  square 
  tunnel 
  which 
  sloped 
  gently 
  

   upwards. 
  Two 
  rollers 
  outside 
  the 
  ends 
  of 
  the 
  tunnel 
  carried 
  an 
  endless 
  

   band 
  of 
  cloth, 
  on 
  which 
  the 
  seeds 
  to 
  be 
  tested 
  were 
  placed 
  and 
  thus 
  

   carried 
  through 
  the 
  tunnel. 
  It 
  was 
  found 
  that 
  exposure 
  to 
  a 
  tempera- 
  

   ture 
  between 
  75° 
  and 
  94° 
  killed 
  all 
  the 
  larvae 
  without 
  affecting 
  germi- 
  

   nation. 
  The 
  results 
  might 
  possibly 
  have 
  been 
  different 
  if 
  the 
  seed 
  had 
  

   been 
  resting 
  on 
  metal 
  instead 
  of 
  cloth, 
  and 
  caution 
  is 
  urged 
  if 
  this 
  

   method 
  of 
  hot 
  air 
  treatment 
  is 
  used. 
  In 
  a 
  second 
  series 
  of 
  experi- 
  

   ments, 
  the 
  seed 
  was 
  lying 
  on 
  a 
  sheet 
  of 
  asbestos, 
  and 
  here 
  four 
  minutes 
  

   s,t 
  80° 
  appear 
  to 
  have 
  been 
  perfectly 
  effective 
  in 
  kilHng 
  the 
  caterpillars, 
  

   without 
  unduly 
  affecting 
  the 
  seed. 
  Any 
  hot-air 
  machine 
  must 
  be 
  

  

  ted. 
  To 
  test 
  the 
  possibility 
  of 
  killing 
  Gelechia 
  larvae 
  by 
  subjecting 
  

  

  