﻿138 
  EEPORT 
  UNITED 
  STATES 
  ENTOMOLOGICAL 
  COMMISSION. 
  

  

  those 
  that 
  have 
  undergoue 
  their 
  changes 
  and 
  lay 
  their 
  eggs 
  in 
  a 
  higher 
  

   temperature. 
  I 
  have 
  noticed 
  that 
  a 
  high 
  temperature 
  has 
  a 
  good 
  deal 
  

   to 
  do 
  with 
  the 
  activity 
  of 
  the 
  moth 
  of 
  the 
  Army 
  Worm. 
  

  

  The 
  migration 
  of 
  the 
  worms 
  is 
  not 
  always 
  in 
  quest 
  of 
  food, 
  though 
  at 
  

   this 
  period, 
  like 
  all 
  worms 
  of 
  this 
  class, 
  they 
  are 
  ravenous. 
  There 
  has 
  

   been 
  a 
  migration 
  into 
  a 
  field 
  in 
  this 
  vicinity 
  which 
  I 
  have 
  closely 
  

   watched. 
  Before 
  leaving 
  a 
  wheat-field, 
  where 
  there 
  was 
  an 
  abundance 
  

   of 
  food, 
  the 
  worms 
  showed 
  an 
  uneasiness 
  similar 
  to 
  that 
  shown 
  by 
  the 
  

   silk 
  worm 
  before 
  spinning 
  its 
  cocoon 
  (moving 
  the 
  head 
  from 
  right 
  to 
  

   left). 
  The 
  first 
  move 
  was 
  into 
  the 
  blue 
  grass 
  {Poa 
  pratensis), 
  and 
  then 
  

   across 
  a 
  traveled 
  road 
  into 
  a 
  field 
  of 
  corn 
  partly 
  plowed 
  over 
  with 
  the 
  

   rows 
  in 
  the 
  same 
  direction 
  the 
  worms 
  were 
  going. 
  They 
  ate 
  for 
  10 
  to 
  

   15 
  rows 
  every 
  bit 
  of 
  corn 
  on 
  the 
  ploiced 
  grotindand 
  but 
  little 
  on 
  the 
  un- 
  

   plowed. 
  As 
  they 
  advanced 
  the 
  destruction 
  was 
  less 
  and 
  less, 
  nearly 
  

   stripping 
  the 
  leaves 
  of 
  the 
  30th 
  and 
  40th 
  rows, 
  and 
  entirely 
  leaving 
  the 
  

   unplowed 
  ground. 
  These 
  worms 
  were 
  of 
  a 
  very 
  uniform 
  size 
  — 
  full 
  

   grown. 
  

  

  To-day 
  I 
  examined 
  a 
  few 
  hills 
  of 
  corn 
  on 
  the 
  boundary 
  of 
  their 
  eating 
  

   as 
  they 
  were 
  congregating 
  around 
  the 
  hills 
  of 
  corn 
  in 
  their 
  migration. 
  

   I 
  looked 
  there 
  first, 
  and 
  at 
  a 
  single 
  hill 
  found 
  18 
  chrysalides 
  under 
  one 
  

   small 
  clod. 
  I 
  think 
  this 
  horde 
  of 
  worms 
  left 
  this 
  wheat-field 
  because 
  it- 
  

   was 
  unfit 
  for 
  the 
  change 
  from 
  larva 
  to 
  chrysalis, 
  not 
  offering 
  any 
  shelter, 
  

   as 
  the 
  ground 
  in 
  the 
  wheat-field 
  was 
  smoothly 
  beaten 
  down 
  by 
  rain 
  

   and 
  was 
  very 
  hard. 
  Where 
  food 
  is 
  abundant 
  and 
  shelter 
  can 
  be 
  found 
  

   for 
  the 
  larvae 
  to 
  undergo 
  their 
  changes, 
  they 
  will 
  not 
  migrate, 
  but 
  from 
  

   either 
  a 
  shortness 
  of 
  food 
  or 
  unfavorable 
  locality 
  for 
  chrysalides 
  they 
  

   will 
  move. 
  If 
  the 
  worms 
  are 
  full 
  grown 
  the 
  damage 
  will 
  be 
  but 
  little 
  

   compared 
  with 
  the 
  migration 
  from 
  a 
  shortness 
  of 
  food 
  by 
  the 
  worms 
  of 
  

   a 
  small 
  size. 
  

  

  In 
  the 
  shape 
  of 
  the 
  ditch, 
  to 
  defend 
  a 
  field 
  against 
  their 
  incursions, 
  

   there 
  has 
  been 
  in 
  this 
  locality 
  quite 
  an 
  imj)rovement 
  over 
  the 
  old 
  un- 
  

   dercut 
  ditch. 
  It 
  is 
  made 
  by 
  dragging 
  along 
  the 
  ditch 
  a 
  ditching-gouge, 
  

   such 
  as 
  is 
  used 
  in 
  laying 
  3-inch 
  tile 
  in 
  the 
  angle 
  of 
  the 
  ditch. 
  

  

  The 
  cutting 
  is 
  on 
  the 
  side 
  you 
  wish 
  to 
  defend, 
  this 
  half-round 
  cut 
  

   being 
  made 
  by 
  a 
  horizontal 
  motion, 
  leaving 
  a 
  smoother 
  surface 
  on 
  the 
  

   half-round 
  than 
  can 
  be 
  done 
  by 
  undercutting 
  with 
  a 
  spade, 
  and 
  I 
  have 
  

   never 
  seen 
  a 
  worm 
  pass 
  the 
  ui)per 
  angle 
  in- 
  this 
  pattern 
  of 
  ditch. 
  — 
  [J. 
  

   0. 
  Andras, 
  Manchester, 
  Scott 
  Countj^, 
  Illinois, 
  June 
  22, 
  1882. 
  

  

  My 
  brother, 
  Alfred 
  R. 
  Swann, 
  who 
  resides 
  on 
  his 
  farm 
  in 
  Jefferson 
  

   County, 
  Tennessee, 
  writes 
  me 
  that 
  Army 
  Worms 
  have 
  appeared 
  in 
  vast 
  

   numbers 
  and 
  are 
  now 
  destroying 
  his 
  grain 
  and 
  grass 
  crops. 
  The 
  same 
  

   thing 
  occurred 
  last 
  season, 
  and 
  as 
  this 
  farm 
  is 
  a 
  very 
  valuable 
  one 
  — 
  

   nearly 
  one 
  thousand 
  acres, 
  a 
  large 
  part 
  of 
  which 
  is 
  river-bottom 
  lands 
  — 
  

   the 
  loss 
  involved 
  will 
  amount 
  to 
  several 
  thousand 
  dollars. 
  (It 
  is 
  known 
  

   as 
  the 
  Eagle 
  Bend 
  Farm.) 
  — 
  [James 
  Swann, 
  New 
  York, 
  June 
  30, 
  1882. 
  

  

  