﻿338 
  

  

  THE 
  NATIONAL 
  GEOGRAPHIC 
  MAGAZINE 
  

  

  Photograph 
  by 
  J. 
  S. 
  Houser 
  

   THE 
  ADULT 
  CATALPA 
  SPHINX 
  MOTH 
  ON 
  

   THE 
  TRUNK 
  OP 
  A 
  TREE 
  IS 
  SCARCELY 
  

   DISTINGUISHABLE 
  

  

  The 
  gray-mottled 
  wing 
  coloring 
  blends 
  al- 
  

   most 
  perfectly 
  with 
  the 
  bark, 
  presenting 
  an 
  

   excellent 
  example 
  of 
  protective 
  coloration. 
  

  

  requirement, 
  and 
  with 
  experience 
  in 
  ma- 
  

   nipulating 
  the 
  plane 
  in 
  the 
  application 
  of 
  

   the 
  insecticide 
  the 
  amount 
  of 
  poison 
  used 
  

   could 
  be 
  reduced 
  considerably. 
  

  

  POfSON 
  DUST 
  WROUGHT 
  HAVOC 
  AMONG 
  

   CATERPILLAR 
  ENEMY 
  

  

  The 
  outstanding 
  feature 
  of 
  the 
  appli- 
  

   cation 
  was 
  the 
  remarkable 
  precision 
  with 
  

   which 
  the 
  poison 
  could 
  be 
  placed 
  at 
  the 
  

   point 
  intended, 
  thus 
  dispelling 
  the 
  idea 
  

   expressed 
  by 
  many 
  before 
  the 
  test 
  was 
  

   marie 
  that 
  the 
  poison 
  dust 
  would 
  be 
  tossed 
  

   willy-nilly 
  by 
  the 
  air 
  currents 
  — 
  wholly 
  

   beyond 
  control. 
  

  

  On 
  the 
  morning 
  following 
  the 
  applica- 
  

   tion 
  of 
  the 
  dust 
  some 
  of 
  the 
  caterpillars 
  

   were 
  dead 
  and 
  many 
  were 
  ailing. 
  Forty- 
  

  

  six 
  hours 
  after 
  the 
  fog 
  of 
  dust 
  had 
  pol- 
  

   luted 
  their 
  food, 
  the 
  evidences 
  of 
  the 
  

   wholesale 
  destruction 
  of 
  the 
  insects 
  were 
  

   everywhere 
  apparent. 
  

  

  Hanging 
  on 
  the 
  branches 
  and 
  remnants 
  

   of 
  foliage, 
  on 
  fence 
  posts 
  and 
  weeds; 
  

   lying 
  on 
  the 
  forest 
  floor 
  and 
  secreted 
  be- 
  

   neath 
  its 
  refuge 
  were 
  literally 
  millions 
  of 
  

   the 
  insects. 
  Not 
  a 
  step 
  could 
  be 
  taken 
  

   without 
  crushing 
  numbers 
  of 
  them, 
  some 
  

   of 
  which 
  already 
  had 
  begun 
  to 
  putrefy. 
  

  

  Large 
  sheets 
  had 
  been 
  spread 
  beneath 
  

   the 
  trees 
  to 
  record 
  the 
  dead 
  caterpillars 
  

   as 
  they 
  fell, 
  but 
  here 
  again 
  the 
  photo- 
  

   graphic 
  record 
  is 
  inadequate, 
  for 
  the 
  

   dying 
  insects 
  had 
  a 
  tendency 
  to 
  use 
  what 
  

   strength 
  remained 
  to 
  crawl 
  off 
  the 
  sheet 
  

   to 
  die 
  in 
  seclusion. 
  Nevertheless, 
  on 
  five 
  

   square 
  feet 
  of 
  one 
  of 
  the 
  sheets 
  ioo 
  dead 
  

   insects 
  were 
  counted. 
  

  

  The 
  effect 
  on 
  the 
  insects 
  had 
  far 
  ex- 
  

   ceeded 
  our 
  fondest 
  expectations. 
  We 
  

   had 
  confidently 
  believed 
  that 
  the 
  smaller 
  

   caterpillars 
  would 
  be 
  killed, 
  but 
  had 
  

   scarcely 
  dared 
  to 
  hope 
  that 
  we 
  would 
  be 
  

   able 
  to 
  kill 
  the 
  large 
  larvae, 
  since 
  it 
  is 
  a 
  

   well 
  known 
  fact 
  that 
  the 
  full-grown 
  cater- 
  

   pillars 
  are 
  difficult 
  to 
  poison. 
  

  

  A 
  careful 
  investigation 
  revealed 
  the 
  as- 
  

   tonishing 
  fact 
  that 
  not 
  over 
  i 
  per 
  cent 
  of 
  

   the 
  caterpillars 
  remained 
  alive 
  on 
  the 
  trees, 
  

   and 
  the 
  minute 
  observations 
  and 
  notes 
  by 
  

   the 
  experts 
  who 
  witnessed 
  the 
  test 
  pre- 
  

   clude 
  the 
  idea 
  that 
  the 
  destruction 
  of 
  the 
  

   insects 
  could 
  be 
  attributed 
  to 
  any 
  other 
  

   agency 
  than 
  the 
  poison. 
  

  

  MAY 
  BE 
  ADAPTED 
  TO 
  PlGHTlNG 
  COTTON 
  

  

  PESTS 
  

  

  When 
  one 
  considers 
  the 
  success 
  which 
  

   attended 
  the 
  test, 
  conducted 
  as 
  it 
  was 
  with 
  

   crude 
  apparatus 
  and 
  without 
  the 
  aid 
  of 
  a 
  

   guiding 
  experience 
  in 
  the 
  manipulation 
  of 
  

   the 
  machine, 
  it 
  seems 
  certain 
  that 
  the 
  air- 
  

   plane 
  will 
  be 
  used 
  successfully 
  in 
  the 
  

   future 
  to 
  control 
  forest 
  insects. 
  

  

  Whether 
  it 
  will 
  be 
  possible 
  to 
  employ 
  

   this 
  method 
  for 
  the 
  treatment 
  of 
  cotton 
  

   or 
  other 
  low 
  growing 
  crops, 
  or 
  even 
  in 
  

   large 
  fruit 
  orchards 
  which 
  permit 
  the 
  

   economical 
  use 
  of 
  terrestrial 
  machines, 
  re- 
  

   mains 
  to 
  be 
  seen. 
  In 
  the 
  treatment 
  of 
  

   tall 
  trees 
  in 
  park 
  and 
  forest 
  areas 
  the 
  tre- 
  

   mendous 
  saving 
  in 
  time 
  and 
  labor 
  in 
  

   which 
  its 
  use 
  results 
  would 
  seem 
  to 
  indi- 
  

   cate 
  that 
  the 
  method 
  is 
  wholly 
  practicable. 
  

  

  