﻿10() 
  

  

  NOTE 
  ON 
  A 
  NEW 
  DISEASE 
  OF 
  THE 
  ARMY 
  WORM. 
  

  

  iLciicdiiid 
  uuipunvtd 
  Hawokth.i 
  

  

  A 
  minor 
  ontbrrak 
  of 
  the 
  army 
  worm 
  in 
  the 
  vicinity 
  of 
  Champaign 
  

   whicli 
  oc-curred 
  in 
  May, 
  1896, 
  was 
  brought 
  to 
  an 
  extraordinary 
  ter- 
  

   mination 
  by 
  the 
  appearance 
  of 
  a 
  fatal 
  disorder 
  of 
  a 
  kind 
  not 
  hitherto 
  

   observed 
  in 
  this 
  species. 
  While 
  my 
  observations 
  were 
  limited 
  to 
  the 
  

   Experiment 
  Station 
  farm 
  and 
  its 
  immediate 
  vicinity, 
  the 
  widespreafl 
  

   occurrence 
  of 
  this 
  disease 
  throughout 
  Central 
  Illinois 
  was 
  shown 
  ))y 
  

   letters 
  anid 
  specimens 
  sent 
  me 
  by 
  several 
  corresponder.ts 
  at 
  about 
  this 
  

   time. 
  

  

  So 
  far 
  as 
  known, 
  destructive 
  outbre; 
  ks 
  of 
  this 
  insect 
  have 
  heretp- 
  

   fore 
  been 
  brought 
  to 
  a 
  conclusion 
  mainly 
  by 
  insect 
  parasites, 
  which 
  

   multiply 
  so 
  rapidly 
  among 
  the 
  concentrated 
  hordes 
  of 
  the 
  army 
  worm 
  

   that 
  they 
  are 
  almost 
  certain 
  to 
  reduce 
  the 
  species 
  to 
  insigniticance 
  

   before 
  another 
  generation 
  can 
  take 
  the 
  field. 
  In 
  this 
  Champaign 
  count 
  j' 
  

   case, 
  however, 
  deaths 
  by 
  insect 
  parasitism 
  were 
  insignificant 
  in 
  num- 
  

   ber 
  compared 
  with 
  those 
  due 
  to 
  the 
  new 
  disease 
  — 
  a 
  fact 
  which 
  I 
  ascer- 
  

   tained 
  by 
  keeping 
  under 
  observation 
  in 
  breeding-cages, 
  with 
  an 
  

   abundant 
  sujjply 
  of 
  food, 
  large 
  numbers 
  of 
  army 
  worms 
  collected 
  at 
  

   random. 
  

  

  Attention 
  was 
  first 
  called 
  to 
  this 
  disease 
  by 
  the 
  occurrence 
  of 
  many 
  

   dead 
  or 
  disabled 
  arrijy 
  worms 
  fastened 
  to 
  the 
  upper 
  part 
  of 
  standing 
  

   stalks 
  of 
  blue 
  grass, 
  to 
  wdiich 
  they 
  commonly 
  clung 
  b)' 
  theil* 
  false 
  

   legs 
  or 
  sometimes 
  by 
  their 
  entire 
  length. 
  These 
  were 
  in 
  various 
  

   stages 
  of 
  degeneration, 
  some 
  of 
  them 
  still 
  living, 
  and 
  merely 
  torpid 
  

   when 
  disturbed, 
  and 
  others 
  dead 
  and 
  dried 
  away 
  to 
  shriveled 
  rem- 
  

   nants 
  of 
  the 
  emj3ty 
  skin. 
  Looking 
  across 
  an 
  infested 
  field 
  of 
  grass 
  

   hundreds 
  of 
  caterpillars 
  exposed 
  in 
  this 
  manner 
  might 
  be 
  seen 
  at 
  

   once, 
  and 
  search 
  on 
  the 
  groundamongthegrassblades 
  would 
  disclose 
  

   a 
  great 
  many 
  more. 
  Of 
  those 
  brought 
  in 
  from 
  the 
  field 
  and 
  confined 
  

   in 
  boxes 
  or 
  cages 
  for 
  observation 
  scarcely 
  oi;e 
  survived 
  to 
  complete 
  

   its 
  transformations. 
  

  

  The 
  bodies 
  of 
  the 
  insects 
  were 
  always 
  blackened 
  when 
  very 
  se- 
  

   riously 
  affected, 
  and 
  at 
  death 
  would 
  rapidly 
  soften, 
  the 
  whole 
  interior 
  

   becoming 
  finally 
  converted 
  into 
  a 
  thick 
  broth 
  or 
  gruel 
  of 
  a 
  dirty 
  

   cream 
  color 
  or 
  a 
  grayish 
  white. 
  The 
  disease 
  usually 
  began 
  at 
  the 
  

   hinder 
  end 
  of 
  the 
  body 
  and 
  moved 
  gradually 
  forward, 
  the 
  last 
  seg- 
  

   ments 
  l)oing 
  sometimes 
  dead, 
  blackened, 
  and 
  almost 
  rotten 
  while 
  the 
  

   anterior 
  parts 
  were 
  so 
  far 
  alive 
  that 
  the 
  caterpillar 
  could 
  crawl 
  slug- 
  

   gisldy 
  about 
  when 
  disturbed. 
  The 
  bodies 
  did 
  not, 
  however, 
  soften 
  

  

  