﻿700 
  REPORT 
  UNITED 
  STATES 
  GEOLOGICAL 
  SURVEY. 
  

  

  " 
  By 
  carefully 
  watching, 
  I 
  have 
  ascertained 
  that 
  the 
  favorite 
  place 
  to 
  

   which 
  the 
  female 
  consigns 
  her 
  eggs 
  in 
  such 
  grass 
  is 
  along 
  the 
  inner 
  

   base 
  of 
  the 
  terminal 
  blades 
  where 
  they 
  are 
  yet 
  doubled. 
  The 
  com- 
  

   pressed 
  horney 
  ovipositor, 
  which 
  piays 
  with 
  great 
  ease 
  and 
  tentative 
  

   motion 
  on 
  the 
  two 
  telescopic 
  subjoints 
  of 
  the 
  abdomen, 
  * 
  * 
  * 
  * 
  js 
  

   thrust 
  in 
  between 
  the 
  folded 
  sides 
  of 
  the 
  blade, 
  and 
  the 
  eggs 
  are 
  glued 
  

   along 
  the 
  groove 
  in 
  rows 
  of 
  from 
  five 
  to 
  twenty, 
  and 
  covered 
  with 
  a 
  

   white, 
  glistening, 
  adhesive 
  fluid, 
  which 
  not 
  only 
  fastens 
  them 
  to 
  each 
  

   other, 
  but 
  draws 
  the 
  two 
  sides 
  of 
  the 
  grass-blade 
  close 
  around 
  them, 
  so 
  

   that 
  nothing 
  but 
  a 
  narrow, 
  glistening 
  streak 
  is 
  visible. 
  * 
  # 
  * 
  * 
  

   The 
  female, 
  having 
  once 
  commenced 
  to 
  lay, 
  is 
  extremely 
  active 
  and 
  

   busy, 
  especially 
  during 
  warm 
  nights, 
  and 
  I 
  should 
  judge 
  that 
  but 
  two 
  

   or 
  three 
  days 
  are 
  required 
  to 
  empty 
  the 
  ovaries, 
  which 
  have 
  a 
  uniform 
  

   development. 
  A 
  string 
  of 
  fifteen 
  or 
  twenty 
  eggs 
  is 
  placed 
  in 
  position 
  

   in 
  two 
  or 
  three 
  minutes, 
  and 
  by 
  the 
  end 
  of 
  ten 
  more 
  I 
  have 
  known 
  the 
  

   moth 
  to 
  choose 
  another 
  leaf, 
  and 
  supply 
  it 
  with 
  another 
  string. 
  Many 
  

   must 
  be 
  laid 
  very 
  soon 
  after 
  vegetation 
  starts, 
  as 
  some 
  moths 
  taken 
  iia 
  

   the 
  middle 
  of 
  April 
  had 
  already 
  exhausted 
  their 
  supply 
  ; 
  yet 
  the 
  bulk 
  

   of 
  them 
  are 
  not 
  laid 
  till 
  toward 
  the 
  end 
  of 
  April." 
  The 
  hatching 
  of 
  the 
  

   larva 
  in 
  a 
  uniform 
  temperature 
  of 
  75° 
  F. 
  takes 
  place 
  from 
  the 
  8th 
  to 
  the 
  

   10th 
  day 
  after 
  deposition. 
  The 
  larvte 
  molt 
  five 
  times, 
  and 
  but 
  three 
  

   days 
  while 
  in 
  confinement 
  intervened 
  on 
  an 
  average 
  between 
  each. 
  — 
  

   (Eiley's 
  Eighth 
  Report.) 
  

  

  In 
  Illinois, 
  the 
  moth 
  lays 
  its 
  eggs 
  in 
  April 
  and 
  May, 
  from 
  four 
  to 
  six 
  

   weeks 
  earlier 
  than 
  in 
  the 
  Eastern 
  States 
  ; 
  so 
  the 
  larva 
  appears 
  earlier. 
  

   In 
  Missouri, 
  from 
  the 
  middle 
  of 
  April 
  till 
  the 
  middle 
  of 
  May, 
  and 
  

   about 
  the 
  middle 
  of 
  June 
  probably 
  in 
  Massachusetts, 
  and 
  a 
  week 
  later 
  

   in 
  Maine, 
  the 
  eggs 
  placed 
  in 
  local 
  and 
  confined 
  tracts 
  of 
  grass-land 
  

   hatch 
  their 
  young 
  larvae, 
  which 
  for 
  four 
  weeks 
  or 
  thereabout 
  feed 
  inces- 
  

   santly 
  till 
  full-fed 
  on 
  the 
  grass 
  around 
  the 
  place 
  of 
  their 
  birth, 
  straying 
  

   off 
  as 
  their 
  forage 
  is 
  eaten 
  up 
  to 
  fresh 
  pastures. 
  

  

  The 
  caterpillar 
  state 
  lasts 
  for 
  about 
  a 
  month, 
  when 
  it 
  descends 
  into 
  

   the 
  earth 
  and 
  changes 
  to 
  a 
  chrysalis, 
  remaining 
  in 
  this 
  state 
  two 
  or 
  

   three 
  weeks. 
  In 
  Southern 
  Missouri 
  the 
  moth 
  appears 
  about 
  the 
  fore 
  

   part 
  of 
  June. 
  — 
  (Eiley.) 
  In 
  New 
  England 
  the 
  moth 
  appears 
  in 
  

  

  It 
  is 
  probable, 
  according 
  to 
  the 
  observations 
  of 
  Mr. 
  Riley 
  and 
  myself, 
  

   that 
  while 
  the 
  majority 
  of 
  the 
  moths 
  appear 
  in 
  the 
  late 
  summer 
  or 
  early 
  

   autumn, 
  according 
  to 
  the 
  latitude 
  of 
  the 
  place 
  where 
  they 
  live, 
  a 
  few 
  

   may 
  hybernate 
  in 
  the 
  pupa 
  state 
  in 
  the 
  Middle 
  States, 
  and 
  still 
  more 
  

   in 
  the 
  New 
  England 
  States. 
  Mr. 
  Riley 
  thinks 
  that 
  the 
  moths 
  may 
  

   sometimes 
  lay 
  their 
  eggs 
  upon 
  newly-sown 
  fall-grain. 
  

  

  We 
  first 
  hear 
  of 
  the 
  army-worm 
  when 
  it 
  is 
  about 
  an 
  inch 
  long; 
  but 
  

   it 
  has 
  eaten 
  up 
  all 
  the 
  grass 
  around 
  its 
  place 
  of 
  birth, 
  and 
  in 
  myriads 
  is 
  

   pushing 
  out 
  its 
  columns 
  after 
  forage. 
  The 
  mature 
  larva 
  is 
  about 
  an 
  

   inch 
  and 
  a 
  half 
  long. 
  Its 
  cylindrical 
  body, 
  divided 
  into 
  thirteen 
  rings 
  

   becomes 
  more 
  contracted 
  and 
  wrinkled 
  at 
  each 
  end, 
  and 
  is 
  sparsely 
  

   covered 
  with 
  short 
  hairs. 
  The 
  head 
  is 
  covered 
  by 
  a 
  net-work 
  of 
  con- 
  

   fluent 
  spots, 
  while 
  along 
  the 
  middle 
  of 
  the 
  face 
  run 
  two 
  lines 
  diverging 
  

   at 
  each 
  end. 
  A 
  light-colored 
  waved 
  line 
  just 
  above 
  the 
  legs 
  is 
  suc- 
  

   ceeded 
  by 
  a 
  dark 
  one, 
  then 
  a 
  light 
  one 
  edged 
  with 
  two 
  thread-like 
  lines 
  ; 
  

   while 
  the 
  upper 
  part 
  is 
  dark, 
  with 
  an 
  interrupted 
  white 
  threadru 
  nning 
  

   exactly 
  through 
  the 
  middle 
  of 
  the 
  back. 
  The 
  prolegs, 
  ten 
  in 
  number, 
  

   are 
  marked 
  on 
  their 
  outer 
  middle 
  and 
  on 
  their 
  tip 
  with 
  black. 
  Beneath, 
  

   the 
  caterpillar 
  is 
  of 
  a 
  livid 
  green. 
  

  

  Its 
  name 
  is 
  suggestive 
  of 
  the 
  regular, 
  trained 
  way 
  in 
  which 
  myriads 
  

   of 
  these 
  caterpillars 
  march 
  together 
  in 
  long, 
  deep 
  columns, 
  side 
  by 
  side, 
  

  

  