﻿792 
  EEPORT 
  UNITED 
  STATES 
  GEOLOGICAL 
  SUEVEY. 
  j 
  

  

  an 
  injurious 
  insect, 
  to 
  Eastern 
  Massachusetts 
  and 
  Connecticut, 
  it 
  is 
  now 
  

   injurious 
  in 
  Illinois 
  and 
  Missouri. 
  It 
  must 
  originally, 
  at 
  least 
  A. 
  vernata, 
  

   have 
  occurred 
  all 
  over 
  the 
  United 
  States 
  east 
  of 
  the 
  Mississippi, 
  as 
  I 
  

   have 
  received 
  it 
  from 
  Texas. 
  It 
  may 
  possibly 
  be 
  introduced 
  into 
  the 
  

   Territories, 
  and 
  therefore 
  I 
  refer 
  to 
  it 
  simply 
  in 
  this 
  connection. 
  

  

  Let 
  us 
  now 
  examine 
  the 
  life-history 
  of 
  a 
  canker-worm. 
  And 
  here 
  we 
  

   will 
  confine 
  ourselves 
  to 
  a 
  single 
  species, 
  the 
  Anisopteryx 
  vernata 
  of 
  

   Peck, 
  which 
  appears 
  in 
  the 
  spring, 
  not 
  touching 
  at 
  present 
  on 
  the 
  ; 
  

   autumnal 
  species. 
  About 
  the 
  1st 
  of 
  May, 
  at 
  the 
  time 
  when 
  the 
  leaves 
  

   of 
  the 
  apple 
  are 
  unfolding, 
  the 
  young 
  canker-worms 
  break 
  through 
  the 
  

   eggs, 
  which 
  have 
  been 
  laid 
  earlier 
  in 
  the 
  season, 
  in 
  March 
  and 
  April, 
  in 
  

   patches 
  on 
  the 
  bark 
  of 
  the 
  trunk 
  and 
  limbs. 
  They 
  may 
  be 
  soon 
  found 
  

   clustering 
  on 
  the 
  terminal 
  buds 
  and 
  partly 
  unfolded 
  leaves, 
  and 
  are 
  

   then 
  about 
  a 
  line 
  in 
  length, 
  and 
  not 
  much 
  thicker 
  than 
  a 
  bit 
  of 
  thick 
  

   thread. 
  

  

  How 
  they 
  grow 
  and 
  devour 
  every 
  green 
  thing 
  on 
  the 
  tree 
  is 
  too 
  well 
  

   known 
  to 
  the 
  fruit-raisers 
  in 
  the 
  eastern 
  j)art 
  of 
  Massachusetts. 
  Fortu- 
  

   nately, 
  owing 
  to 
  the 
  want 
  of 
  wings, 
  the 
  female 
  is 
  exceedingly 
  sedentary, 
  

   and 
  year 
  after 
  year 
  the 
  trees 
  of 
  particular 
  orchards 
  and 
  towns 
  are 
  defo- 
  

   liated 
  and 
  turned 
  brown, 
  while 
  adjoining 
  orchards 
  and 
  towns 
  scarcely 
  

   suffer. 
  By 
  the 
  20th 
  of 
  June, 
  in 
  Essex 
  County, 
  Massachusetts, 
  the 
  orch- 
  

   ard 
  looks 
  as 
  if 
  a 
  iire 
  had 
  run 
  through 
  it. 
  At 
  that 
  date 
  the 
  worms 
  are 
  

   fully 
  fed, 
  and 
  they 
  then 
  descend 
  to 
  the 
  ground, 
  letting 
  themselves 
  down 
  

   by 
  a 
  silken 
  thread. 
  At 
  this 
  time 
  I 
  have 
  destroyed 
  thousands 
  by 
  jarring 
  

   the 
  tree 
  and 
  collecting 
  those 
  which 
  fall 
  down. 
  I 
  have 
  watched 
  old 
  and 
  

   young 
  robins 
  busily 
  engaged 
  in 
  eating 
  them, 
  and 
  from 
  the 
  number 
  of 
  

   toads 
  in 
  my 
  garden, 
  gathered 
  about 
  under 
  the 
  trees, 
  I 
  feel 
  confident 
  

   that 
  they 
  eat 
  multitudes 
  of 
  them. 
  

  

  The 
  worms 
  at 
  once 
  enter 
  the 
  ground, 
  change 
  to 
  chrysalids 
  several 
  

   inches 
  below 
  the 
  surface, 
  near 
  the 
  trunk 
  of 
  the 
  tree, 
  and 
  there 
  remain 
  

   until 
  the 
  early 
  days 
  of 
  March 
  and 
  April, 
  when 
  the 
  wingless 
  females 
  

   ascend 
  the 
  trees, 
  and 
  the 
  winged 
  males 
  may 
  be 
  seen 
  fluttering 
  about. 
  

  

  I 
  took: 
  pains 
  one 
  spring, 
  in 
  the 
  middle 
  of 
  April, 
  to 
  count 
  the 
  number 
  

   of 
  these 
  moths 
  on 
  my 
  apple-trees, 
  fourteen 
  in 
  number, 
  averaging 
  from 
  

   6 
  to 
  7 
  inches 
  in 
  thickness, 
  besides 
  three 
  elms. 
  They 
  were 
  more 
  abund- 
  

   ant 
  on 
  the 
  apple-trees 
  than 
  the 
  elms. 
  But 
  on 
  those 
  seventeen 
  trees 
  

   there 
  were 
  counted, 
  adhering 
  mostly 
  to 
  the 
  tarred 
  paper, 
  1,000 
  males 
  

   and 
  200 
  females. 
  The 
  spring 
  of 
  1875 
  was 
  cold 
  and 
  backward, 
  and 
  few 
  

   moths 
  were 
  seen 
  before 
  this 
  date. 
  From 
  these 
  data 
  we 
  can 
  ascertain 
  

   approximately 
  the 
  relative 
  numerical 
  proportions 
  between 
  the 
  sexes, 
  

   which 
  seems 
  to 
  approximate 
  five 
  males 
  to 
  one 
  female. 
  

  

  The 
  species 
  I 
  have 
  referred 
  to 
  is 
  the 
  spring 
  moth, 
  the 
  Anisopteryx 
  

   vernata 
  of 
  Peck, 
  but 
  not 
  of 
  Harris. 
  The 
  other 
  species 
  is 
  much 
  less 
  

   abundant 
  in 
  the 
  adult 
  condition, 
  and 
  only 
  appears 
  in 
  the 
  autumn. 
  The 
  

   wings 
  are 
  thicker 
  than 
  those 
  of 
  vernata, 
  and 
  the 
  caterpillar 
  has 
  an 
  addi- 
  

   tional 
  pair 
  of 
  prop-legs, 
  though 
  so 
  short 
  as 
  to 
  be 
  useless. 
  I 
  find 
  that 
  

   most 
  of 
  the 
  damage 
  is 
  done 
  by 
  the 
  caterpillars 
  of 
  vernata. 
  On 
  June 
  

   35, 
  1875, 
  I 
  collected 
  557 
  caterpillars 
  from 
  the 
  apple-trees 
  in 
  my 
  garden. 
  

   Of 
  these 
  520 
  were 
  vernata, 
  and 
  27 
  were 
  the 
  young 
  of 
  the 
  autumn 
  species. 
  

   Peck, 
  in 
  his 
  account 
  published 
  in 
  1795, 
  states 
  that 
  vernata 
  does 
  the 
  

   IDrincipal 
  damage. 
  

  

  As 
  for 
  remedies, 
  the 
  use 
  of 
  printer's 
  ink 
  laid 
  on 
  tarred 
  paper 
  Is 
  the 
  

   cheapest, 
  though 
  the 
  ink 
  should 
  be 
  applied 
  every 
  day 
  or 
  two. 
  The 
  use 
  

   of 
  tin 
  troughs 
  of 
  oil 
  surrounding 
  the 
  tree 
  is 
  almost 
  sure 
  to 
  stop 
  the 
  

   ascent 
  of 
  the 
  females, 
  while 
  wooden 
  troughs 
  of 
  oil 
  built 
  around 
  the 
  bot- 
  

   tom 
  of 
  the 
  trunk 
  is 
  almost 
  equally 
  eflicacious. 
  Care 
  and 
  attention, 
  and, 
  

  

  

  