﻿CHAPTEE 
  VII. 
  

  

  CANKER 
  WOEMS. 
  

  

  The 
  term 
  Canker 
  Worm 
  has 
  formed 
  the 
  heading 
  of 
  so 
  manj^ 
  articles 
  

   in 
  the 
  various 
  agriculttiral 
  and 
  horticultural 
  journals 
  and 
  magazines^ 
  

   and 
  State 
  and 
  other 
  reports, 
  during 
  the 
  last 
  twenty 
  or 
  twenty-five 
  

   years, 
  and 
  the 
  natural 
  history 
  of 
  these 
  insects 
  has 
  been 
  in 
  many 
  par- 
  

   ticulars 
  so 
  fully 
  given 
  in 
  standard 
  works, 
  that 
  one 
  almost 
  wonders 
  where 
  

   there 
  can 
  be 
  a 
  reading 
  farmer 
  who 
  does 
  not 
  know 
  how 
  properly 
  to 
  cope 
  

   with 
  them; 
  yet 
  information 
  is 
  constantl}^ 
  sought 
  on 
  the 
  subject, 
  and 
  as 
  

   it 
  is 
  only 
  of 
  late 
  years 
  that 
  some 
  essential 
  facts 
  have 
  been 
  fully 
  under- 
  

   stood, 
  we 
  propose 
  to 
  bring 
  together 
  here 
  whatever 
  is 
  necessary 
  to 
  a 
  

   complete 
  understanding 
  of 
  these 
  pests. 
  

  

  To 
  obviate 
  misunderstandings 
  in 
  the 
  outset 
  it 
  should 
  be 
  stated 
  that 
  

   two 
  quite 
  distinct 
  insects 
  have 
  been 
  recognized 
  as 
  properly 
  bearing 
  the 
  

   name 
  of 
  "Canker 
  Worm," 
  while 
  this 
  name 
  is 
  frequently 
  applied 
  improp- 
  

   erly 
  to 
  numerous 
  other 
  insects. 
  

  

  The 
  true 
  Canker 
  Worms 
  of 
  this 
  country 
  are 
  native 
  species, 
  and 
  are 
  

   confined 
  to 
  North 
  America. 
  One 
  of 
  them, 
  however, 
  Anisopteryx 
  pom- 
  

   etaria, 
  is 
  closely 
  related 
  to 
  an 
  European 
  species, 
  Anisopteryx 
  cesculariay 
  

   and 
  resembles 
  the 
  latter 
  so 
  closely, 
  in 
  its 
  adult 
  state, 
  that 
  the 
  two 
  may 
  

   easily 
  be 
  confounded 
  by 
  the 
  inexperienced 
  observer; 
  more 
  easily, 
  

   indeed, 
  than 
  our 
  two 
  native 
  species 
  with 
  each 
  other. 
  The 
  distinctive 
  

   characters 
  of 
  the 
  American 
  and 
  the 
  European 
  Anisopteryx^ 
  even 
  in 
  the 
  

   adult 
  stage, 
  are 
  sufficient, 
  however, 
  for 
  ready 
  discrimination 
  by 
  the 
  

   trained 
  observer, 
  and 
  those 
  in 
  the 
  immature 
  stages 
  are 
  still 
  more 
  evident^ 
  

   as 
  will 
  be 
  shown 
  hereafter. 
  

  

  One 
  of 
  the 
  characters 
  which 
  all 
  species 
  of 
  Canker 
  W^orm 
  moths 
  have 
  

   in 
  common 
  is 
  the 
  possession 
  of 
  ample 
  wings 
  by 
  the 
  male 
  and 
  the 
  lack 
  of 
  

   wings 
  in 
  the 
  female. 
  It 
  is 
  upon 
  this 
  peculiarity 
  of 
  the 
  female 
  that 
  most 
  

   of 
  the 
  propositions 
  of 
  remedies 
  are 
  based. 
  The 
  females 
  generally 
  be- 
  

   ing 
  able 
  to 
  move 
  about, 
  or 
  make 
  their 
  way 
  into 
  the 
  trees 
  to 
  deposit 
  

   their 
  eggs, 
  only 
  by 
  crawling, 
  any 
  efficient 
  means 
  of 
  preventing 
  them 
  

   from 
  ascending 
  upon 
  the 
  trunk 
  to 
  the 
  branches 
  of 
  the 
  trees 
  will 
  

   largely 
  aid 
  in 
  protecting 
  these 
  from 
  damage 
  by 
  the 
  worms, 
  and, 
  if 
  ac- 
  

   companied 
  by 
  such 
  measures 
  as 
  will 
  prevent 
  the 
  newly 
  hatched 
  worms 
  

   from 
  ascending, 
  will 
  prove 
  a 
  perfect 
  preventive. 
  

  

  CLASSIFICATION. 
  

  

  Canker 
  Worms 
  are 
  distinguished 
  from 
  most 
  other 
  caterpillars 
  which 
  

   attack 
  the 
  apple-tree, 
  by 
  having 
  a 
  less 
  number 
  of 
  fleshy 
  supporting 
  legs 
  

  

  157 
  

  

  