﻿HISTORY 
  OF 
  THE 
  DISEASES 
  IN 
  THE 
  UNITED 
  STATES. 
  205 
  

  

  sertion 
  is 
  so 
  great. 
  In 
  this 
  particular 
  article 
  [the 
  one 
  in 
  the 
  Lawrence 
  Journal] 
  we 
  

   notice 
  that 
  no 
  dates 
  are 
  given 
  to 
  the 
  letters, 
  and 
  that 
  the 
  correspondents 
  in 
  no 
  way 
  

   show 
  that 
  the 
  supposed 
  healthy 
  bugs 
  were 
  examined 
  critically, 
  the 
  evidence 
  of 
  life 
  

   being 
  assumed 
  to 
  mean 
  healthfulness. 
  The 
  chief 
  difficulty 
  is, 
  that 
  at 
  the 
  time 
  when 
  

   the 
  disease 
  is 
  prevalent 
  in 
  one 
  locality, 
  the 
  same 
  climate 
  and 
  zymotic 
  conditions 
  are 
  

   liable 
  to 
  — 
  and 
  in 
  fact 
  usually 
  do 
  — 
  prevail 
  through 
  a 
  wide 
  extent 
  of 
  country, 
  and 
  

   that 
  the 
  disease 
  may 
  be 
  about 
  to 
  appear 
  over 
  the 
  whole 
  area. 
  This 
  at 
  once 
  estab- 
  

   lishes 
  the 
  necessity 
  of 
  the 
  most 
  careful 
  observations 
  by 
  means 
  of 
  check 
  experiments. 
  

   If 
  the 
  diseased 
  bugs 
  are 
  simply 
  placed 
  among 
  apparently 
  healthy 
  bugs 
  and 
  the 
  lat- 
  

   ter 
  subsequently 
  become 
  diseased, 
  the 
  proof 
  of 
  direct 
  transmittal 
  by 
  contagion 
  is 
  

   but 
  negative. 
  If, 
  however, 
  healthy 
  bugs 
  are 
  isolated 
  from 
  the 
  imported 
  diseased 
  

   bugs 
  and 
  remain 
  healthy, 
  then 
  a 
  probability 
  is 
  established 
  in 
  favor 
  of 
  the 
  contagion 
  

   by 
  contamination. 
  The 
  disease 
  is 
  always 
  most 
  prevalent 
  in 
  cool, 
  wet 
  weather, 
  from 
  

   midsummer 
  on, 
  when 
  large 
  numbers 
  of 
  the 
  older 
  bugs 
  are 
  naturally 
  dying 
  from 
  

   other 
  causes, 
  and 
  are 
  probably 
  more 
  liable 
  to 
  fall 
  victims 
  to 
  any 
  scourge 
  of 
  this 
  

   kind. 
  

  

  The 
  subject 
  is 
  of 
  extreme 
  interest, 
  and 
  while 
  there 
  are 
  reasons 
  which 
  would 
  

   make 
  us 
  doubtful 
  of 
  any 
  tangible 
  and 
  practical 
  results 
  following 
  the 
  attempted 
  ar- 
  

   tificial 
  spread 
  and 
  propagation 
  of 
  the 
  disease, 
  and 
  which 
  make 
  us 
  accept 
  with 
  cau- 
  

   tion 
  the 
  more 
  sanguine 
  views 
  of 
  men 
  like 
  Professors 
  Lugger 
  and 
  Snow, 
  yet 
  there 
  is 
  

   sufficient 
  promise 
  of 
  such 
  results 
  to 
  justify 
  the 
  fullest 
  and 
  most 
  careful 
  experimen- 
  

   tation. 
  This 
  will 
  doubtless 
  be 
  had 
  in 
  the 
  next 
  year 
  or 
  so 
  by 
  the 
  cooperation 
  of 
  the 
  

   entomologists 
  connected 
  with 
  the 
  different 
  experiment 
  stations. 
  The 
  full 
  life-his- 
  

   tory 
  of 
  the 
  particular 
  Entomophthora 
  is 
  of 
  extreme 
  importance 
  in 
  this 
  connection. 
  

  

  In 
  1890, 
  the 
  sixteenth 
  report 
  of 
  the 
  Illinois 
  State 
  Entomologist 
  (Professor 
  

   Forbes's 
  fifth 
  report) 
  for 
  the 
  years 
  1887 
  and 
  1888 
  was 
  issued. 
  The 
  report 
  

   records 
  no 
  observations 
  made 
  after 
  1888. 
  The 
  contagious 
  diseases 
  of 
  the 
  

   chinch-bug 
  are 
  discussed 
  on 
  pp. 
  45-49. 
  After 
  referring 
  briefly 
  to 
  his 
  earlier 
  

   observations, 
  Professor 
  Forbes 
  presents 
  his 
  observations 
  during 
  1887 
  and 
  

   1888, 
  stating 
  that 
  it 
  is 
  not 
  a 
  full 
  account, 
  as 
  follows 
  : 
  

  

  The 
  first 
  clearly 
  recognizable 
  cases 
  of 
  fungous 
  disease 
  among 
  these 
  chinch-bugs 
  

   were 
  found 
  by 
  me 
  in 
  a 
  corn 
  field 
  near 
  Shattuc, 
  Clinton 
  county, 
  July 
  7, 
  1887; 
  but 
  as 
  

   the 
  fungus 
  affecting 
  these 
  insects 
  was 
  not 
  an 
  Empusa, 
  but 
  belonged 
  to 
  a 
  genus 
  

   (Botrytis) 
  [Sporotrichum] 
  but 
  very 
  rarely 
  parasitic, 
  no 
  especial 
  attention 
  was 
  paid 
  

   to 
  it 
  at 
  the 
  time. 
  The 
  same 
  fungous 
  affection 
  was 
  next 
  noticed 
  August 
  7, 
  1888, 
  at 
  

   Flora, 
  111. 
  September 
  13 
  the 
  Empusa 
  of 
  1882 
  was 
  collected 
  in 
  Marion 
  county 
  ; 
  and 
  

   September 
  14 
  the 
  bacterial 
  form 
  discovered 
  in 
  1882 
  was 
  observed 
  in 
  immense 
  num- 
  

   bers 
  in 
  the 
  intestines 
  of 
  chinch-bugs 
  obtained 
  at 
  Odin. 
  

  

  With 
  this 
  inspiring 
  evidence 
  that 
  at 
  least 
  three 
  kinds 
  of 
  diseases 
  were 
  at 
  work 
  on 
  

   the 
  chinch-bugs 
  of 
  southern 
  Illinois, 
  active 
  measures 
  were 
  taken 
  at 
  once 
  for 
  the 
  

   fullest 
  possible 
  study 
  of 
  them 
  from 
  every 
  point 
  of 
  view, 
  entomological, 
  bacterial, 
  

   and 
  economic. 
  

  

  Without 
  attempting 
  at 
  this 
  time 
  a 
  full 
  account 
  of 
  our 
  work 
  (still 
  in 
  progress), 
  I 
  

   give 
  a 
  few 
  items 
  bearing 
  especially 
  on 
  the 
  distribution 
  and 
  activity 
  of 
  these 
  dis- 
  

   eases 
  in 
  the 
  State. 
  

  

  The 
  field 
  at 
  Odin, 
  where 
  the 
  bacterial 
  disease 
  was 
  first 
  detected, 
  contained 
  only 
  a 
  

   very 
  moderate 
  number 
  of 
  chinch-bugs 
  for 
  the 
  time 
  and 
  circumstances, 
  and 
  these 
  

   very 
  unequally 
  distributed. 
  The 
  number 
  of 
  adults, 
  especially, 
  was 
  relatively 
  very 
  

   small. 
  The 
  bugs 
  had 
  also 
  a 
  feeble 
  vitality, 
  as 
  shown 
  by 
  the 
  rapidity 
  with 
  which 
  

   they 
  died 
  in 
  transit, 
  although 
  put 
  up 
  with 
  special 
  care. 
  Many 
  pupae 
  were 
  very 
  slug- 
  

  

  