﻿336 
  

  

  THE 
  NATIONAL 
  GEOGRAPHIC 
  MAGAZINE 
  

  

  Photograph 
  by 
  Y. 
  K. 
  Roots 
  

  

  THE 
  EGGS 
  OE 
  THE 
  CATALPA 
  SPHINX 
  (ENLARGED) 
  DEPOSITED 
  

  

  ON 
  A 
  CATALPA 
  LEAP 
  

  

  Each 
  mother 
  moth 
  is 
  capable 
  of 
  laying 
  several 
  hundred 
  eggs. 
  As 
  

   many 
  as 
  a 
  thousand 
  have 
  been 
  taken 
  from 
  a 
  single 
  egg-mass. 
  

  

  eggs 
  in 
  pearly 
  white 
  masses 
  on 
  the 
  leaves 
  

   of 
  the 
  catalpa 
  tree. 
  These 
  eggs 
  within 
  a 
  

   few 
  days 
  give 
  issue 
  to 
  tiny 
  larvae 
  which 
  

   feed 
  upon 
  the 
  foliage 
  and 
  upon 
  reaching 
  

   maturity 
  are 
  as 
  much 
  as 
  three 
  inches 
  long. 
  

   They 
  then 
  pass 
  to 
  the 
  ground, 
  burrow 
  

   down 
  about 
  three 
  inches 
  and 
  transform 
  

   to 
  the 
  pupal 
  stage. 
  

  

  From 
  these 
  pupae 
  emerge 
  the 
  adult 
  

   moths, 
  which 
  proceed 
  to 
  lay 
  their 
  eggs 
  

   for 
  another 
  brood 
  of 
  destructive 
  cater- 
  

   pillars. 
  Only 
  about 
  a 
  month 
  is 
  required 
  

   to 
  pass 
  through 
  the 
  stages 
  from 
  egg 
  to 
  

   moth. 
  

  

  Last 
  year 
  there 
  occurred 
  in 
  Ohio 
  three 
  

   full 
  broods 
  or 
  crops 
  of 
  the 
  caterpillars, 
  

  

  each 
  sufficiently 
  nu- 
  

   merous 
  to 
  defoliate 
  

   completely 
  the 
  grove 
  

   in 
  which 
  they 
  ap- 
  

   peared. 
  Some 
  groves 
  

   put 
  out 
  three 
  full 
  

   crops 
  of 
  foliage 
  and 
  

   each 
  in 
  its 
  turn 
  was 
  

   wholly 
  consumed 
  by 
  

   the 
  ravenous 
  worms. 
  

   Our 
  work 
  was 
  di- 
  

   rected 
  against 
  the 
  sec- 
  

   ond 
  brood 
  of 
  cater- 
  

   pillars 
  working 
  on 
  the 
  

   second 
  crop 
  of 
  foliage. 
  

  

  THE 
  POISON 
  POWDER 
  

  

  RELEASED 
  IN 
  A 
  

  

  DENSE 
  CLOUD 
  

  

  The 
  plane 
  used 
  was 
  a 
  

   Curtis 
  J 
  N 
  6 
  equipped 
  

   with 
  a 
  hopper 
  for 
  

   carrying 
  and 
  liberat- 
  

   ing 
  the 
  poison 
  powder. 
  

   This 
  hopper 
  was 
  se- 
  

   cured 
  to 
  the 
  fuselage 
  

   of 
  the 
  plane 
  by 
  the 
  

   side 
  of 
  the 
  observer's 
  

   seat. 
  It 
  consisted 
  of 
  

   an 
  irregularly 
  shaped 
  

   flat 
  metal 
  box 
  with 
  a 
  

   capacity 
  for 
  holding 
  a 
  

   little 
  more 
  than 
  100 
  

   pounds 
  of 
  dry 
  arse- 
  

   nate 
  of 
  lead 
  powder. 
  

   At 
  the 
  bottom 
  was 
  

   arranged 
  a 
  sliding 
  

   gate, 
  operated 
  by 
  a 
  

   handle 
  accessible 
  to 
  

   the 
  observer 
  in 
  the 
  

   plane. 
  At 
  the 
  top 
  of 
  

   the 
  hopper 
  was 
  a 
  crank, 
  connected 
  by 
  a 
  

   sprocket 
  chain 
  to 
  a 
  revolving 
  mechanism 
  

   in 
  the 
  bottom, 
  which 
  when 
  placed 
  in 
  mo- 
  

   tion 
  dropped 
  the 
  poison 
  powder 
  through 
  

   the 
  previously 
  opened 
  sliding 
  gate. 
  

  

  Immediately 
  upon 
  leaving 
  the 
  hopper 
  

   the 
  dust 
  dropped 
  into 
  the 
  "slip 
  stream" 
  — 
  

   the 
  violent 
  air 
  current 
  set 
  up 
  by 
  the 
  re- 
  

   volving 
  propeller 
  — 
  and 
  was 
  thrown 
  into 
  

   violent 
  agitation 
  in 
  a 
  dense 
  white 
  cloud 
  

   which 
  trailed 
  out 
  behind 
  the 
  moving 
  plane 
  

   as 
  if 
  the 
  machine 
  were 
  on 
  fire 
  and 
  belch- 
  

   ing 
  large 
  volumes 
  of 
  white 
  smoke. 
  

  

  The 
  catalpa 
  grove 
  in 
  which 
  the 
  dusting 
  

   was 
  done 
  was 
  situated 
  on 
  level 
  ground 
  

   and 
  had 
  been 
  planted 
  for 
  the 
  growing 
  of 
  

  

  