﻿REMEDIES 
  AGAINST 
  CANKER 
  WORMS. 
  195 
  

  

  ^* 
  The 
  Spring 
  Cauker 
  Worm, 
  with 
  its 
  chrysalis 
  formed 
  in 
  a 
  simple 
  earthen 
  

   cavity, 
  will 
  be 
  very 
  materially 
  alfecteil 
  by 
  late 
  fall 
  plowing 
  of 
  the 
  soil, 
  

   especially 
  if 
  the 
  soil 
  be 
  of 
  such 
  nature 
  as 
  to 
  crumble 
  easily 
  5 
  for 
  I 
  have 
  

   proved 
  by 
  experiment 
  that 
  whenever 
  this 
  fragile 
  cocoon 
  is 
  disturbed 
  or 
  

   broken 
  open 
  in 
  cold 
  weather, 
  as 
  it 
  very 
  readily 
  is 
  by 
  disturbance 
  of 
  the 
  

   soil, 
  at 
  that 
  season 
  the 
  chrysalis 
  has 
  not 
  the 
  power 
  to 
  penetrate 
  the 
  

   ground 
  again 
  or 
  to 
  form 
  a 
  second 
  cavity, 
  and 
  in 
  the 
  great 
  majority 
  of 
  

   instances 
  either 
  rots, 
  dries 
  out, 
  becomes 
  moldy, 
  or, 
  if 
  on 
  the 
  surface, 
  is 
  

   destroyed 
  by 
  birds. 
  

  

  "Even 
  summer 
  plowing, 
  if 
  performed 
  after 
  the 
  first 
  of 
  July 
  w^ould 
  

   work 
  beneficially; 
  and 
  it 
  is 
  for 
  this 
  reason, 
  that 
  clean, 
  well-cultivated 
  

   •orchards 
  are 
  more 
  free 
  from 
  the 
  attacks 
  of 
  this 
  insect, 
  than 
  slovenly 
  

   xind 
  neglected 
  ones. 
  The 
  only 
  advantage 
  of 
  late 
  fall 
  plowing, 
  lies 
  in 
  the 
  

   facts, 
  that 
  the 
  chrysalis 
  is 
  at 
  that 
  time 
  too 
  benumbed 
  to 
  work 
  itself 
  into 
  

   the 
  ground 
  and 
  form 
  another 
  cell, 
  and 
  that 
  birds 
  are 
  then 
  harder 
  pushed 
  

   for 
  food, 
  and 
  more 
  watchful 
  for 
  any 
  such 
  dainty 
  moreeau. 
  

  

  "As 
  to 
  the 
  efficiency 
  of 
  hogs, 
  in 
  rooting 
  up 
  and 
  devouring 
  the 
  chrys- 
  

   alids, 
  during 
  the 
  summer 
  months, 
  abundant 
  favorable 
  testimony 
  might 
  

   be 
  cited; 
  but 
  the 
  facts 
  are 
  too 
  obvious 
  to 
  need 
  argument. 
  

  

  "With 
  the 
  Fall 
  Canker 
  Worm, 
  on 
  the 
  contrary, 
  these 
  measures 
  will 
  

   avail 
  little, 
  if 
  anything; 
  for 
  the 
  cocoon, 
  composed 
  of 
  a 
  thick 
  layer 
  of 
  

   yielding 
  silk 
  strengthened 
  by 
  the 
  interweaving 
  of 
  particles 
  of 
  earth, 
  can- 
  

   not 
  be 
  broken 
  open 
  by 
  any 
  such 
  processes, 
  and 
  a 
  dozen 
  plowings 
  would 
  

   not 
  expose 
  a 
  single 
  chrysalis. 
  Without 
  doubt 
  we 
  have 
  in 
  these 
  facts 
  a 
  

   valid 
  explanation 
  of 
  the 
  contradictory 
  experience 
  as 
  to 
  the 
  value 
  of 
  fall 
  

   plowing 
  or 
  the 
  use 
  of 
  hogs 
  in 
  an 
  orchard 
  as 
  canker-worm 
  checks. 
  

  

  "That 
  the 
  breaking 
  open 
  of 
  the 
  chrysalis 
  of 
  the 
  Fall 
  species 
  would 
  be 
  

   equally 
  injurious 
  to 
  that 
  species 
  seems 
  to 
  be 
  shown 
  by 
  the 
  result 
  of 
  

   experiments 
  which 
  I 
  made 
  in 
  1875, 
  in 
  trying 
  to 
  raise 
  the 
  perfect 
  insects 
  

   from 
  cocoons 
  which 
  I 
  had 
  cut 
  open 
  in 
  order 
  to 
  examine 
  the 
  chrysalids. 
  

   From 
  58 
  chrysalids, 
  two 
  of 
  which 
  were 
  males 
  and 
  the 
  rest 
  females, 
  I 
  

   obtained 
  only 
  2 
  male 
  and 
  25 
  female 
  imagos; 
  the 
  remainder 
  all 
  perished 
  

   by 
  rot, 
  induced 
  doubtless 
  by 
  this 
  premature 
  opening 
  of 
  the 
  cocoons." 
  

  

  Dr. 
  Harris 
  says^°* 
  that 
  Mr. 
  S. 
  P. 
  Fowler 
  and 
  Mr. 
  John 
  Kenrick, 
  of 
  

   I^ewton, 
  Mass., 
  advise 
  us 
  to 
  remove 
  the 
  soil 
  to 
  the 
  distance 
  of 
  four 
  or 
  

   five 
  feet 
  from 
  the 
  trunk 
  of 
  the 
  trees, 
  and 
  to 
  the 
  depth 
  of 
  six 
  inches, 
  to 
  

   cart 
  it 
  away, 
  and 
  replace 
  it 
  with 
  an 
  equal 
  quantity 
  of 
  comi)ost 
  or 
  rich 
  

   earth. 
  In 
  this 
  way 
  many 
  of 
  the 
  insects 
  will 
  be 
  removed 
  also; 
  but 
  unless 
  

   the 
  earth 
  thus 
  carried 
  away 
  is 
  thrown 
  into 
  some 
  pond-hole, 
  and 
  left 
  

   covered 
  with 
  water, 
  many 
  of 
  the 
  insects 
  contained 
  in 
  it 
  will 
  undergo 
  

   their 
  transformations 
  and 
  come 
  out 
  alive 
  next 
  year. 
  

  

  ENCOUEAGEMEiSTT 
  OF 
  BIRDS 
  — 
  BREEDING 
  OF 
  PARASITES. 
  

  

  It 
  is 
  well 
  known 
  that 
  in 
  Philadelphia, 
  as 
  in 
  many 
  other 
  eastern 
  cities, 
  

   the 
  Canker 
  Worm 
  was 
  formerly 
  a 
  great 
  nuisance, 
  not 
  only 
  because 
  of 
  the 
  

  

  1" 
  Report 
  on 
  Insects 
  of 
  Massachusetts, 
  pp, 
  339-340. 
  

  

  