﻿194 
  CONTAGIOUS 
  DISEASES 
  OF 
  THE 
  CHINCH-BUG. 
  

  

  sota, 
  Dakota, 
  and 
  northern 
  Iowa, 
  in 
  1872. 
  All 
  over 
  the 
  plains 
  the 
  dead 
  were 
  seen 
  

   clasping 
  the 
  stems 
  of 
  grass 
  and 
  weeds, 
  and, 
  before 
  I 
  was 
  aware 
  of 
  this 
  fact, 
  more 
  than 
  

   once 
  I 
  approached 
  cautiously 
  to 
  capture 
  a 
  desired 
  specimen, 
  only 
  to 
  find 
  it 
  dead 
  and 
  

   rigid. 
  In 
  1877 
  the 
  rainy 
  season 
  evidently 
  caused 
  an 
  immense 
  destruction 
  of 
  the 
  

   larva? 
  of 
  Caloptenus 
  spretus 
  [the 
  Rocky 
  Mountain 
  locust]. 
  

  

  In 
  the 
  light 
  of 
  subsequent 
  observations, 
  including 
  my 
  own 
  during 
  the 
  last 
  

   three 
  years, 
  I 
  am 
  convinced 
  that 
  the 
  bugs 
  of 
  1865 
  were 
  carried 
  off 
  as 
  the 
  re- 
  

   sult 
  of 
  the 
  effective 
  parasitism 
  of 
  either 
  Sporotrichum 
  or 
  Empma, 
  the 
  two 
  

   fungi 
  which 
  are 
  continually 
  associated 
  with 
  chinch-bug 
  epidemic 
  diseases. 
  

  

  The 
  wet 
  weather, 
  rather 
  than 
  being 
  the 
  "originating 
  cause," 
  as 
  Doctor 
  

   Thomas 
  unfortunately 
  terms 
  it, 
  was 
  only 
  a 
  condition 
  favorable 
  to 
  the 
  strong- 
  

   est 
  and 
  most 
  rapid 
  development 
  of 
  the 
  parasitic 
  fungus 
  ; 
  a 
  fact 
  plainly 
  shown, 
  

   to 
  my 
  mind, 
  by 
  the 
  data 
  presented 
  in 
  this 
  report. 
  

  

  Messrs. 
  Riley 
  and 
  Walsh, 
  however, 
  were 
  pleased 
  to 
  attribute 
  this 
  wholesale 
  

   destruction 
  of 
  chinches 
  to 
  the 
  direct 
  effect 
  of 
  the 
  moisture.* 
  

  

  Doctor 
  Riley, 
  in 
  his 
  Second 
  Annual 
  Report 
  of 
  the 
  State 
  Entomologist 
  of 
  

   Missouri 
  (1870), 
  ridicules 
  n 
  Doctor 
  Shimer's 
  theory 
  of 
  disease, 
  as 
  follows 
  (pp. 
  

   24,25): 
  

  

  Doctor 
  Shimer, 
  however, 
  is 
  not 
  satisfied 
  with 
  this 
  simple 
  theory 
  [of 
  the 
  destruc- 
  

   tion 
  of 
  chinch-bugs 
  by 
  the 
  direct 
  action 
  of 
  wet 
  weather]. 
  He 
  has 
  gotten 
  up 
  and 
  

   expounded 
  to 
  the 
  world 
  a 
  new 
  and 
  recondite 
  theory 
  of 
  his 
  own, 
  namely, 
  that 
  in 
  the 
  

   terrible 
  wet 
  season 
  of 
  1865, 
  when 
  the 
  Chinch-bug, 
  although 
  in 
  early 
  spring 
  it 
  had 
  

   appeared 
  in 
  very 
  great 
  numbers, 
  was 
  almost 
  annihilated 
  in 
  the 
  course 
  of 
  the 
  sum- 
  

   mer, 
  it 
  perished, 
  not 
  as 
  others 
  had 
  foolishly 
  supposed, 
  from 
  the 
  direct 
  operation 
  of 
  

   the 
  rain, 
  but 
  indirectly, 
  through 
  a 
  mysterious 
  epidemic 
  disease 
  analogous 
  to 
  the 
  

   Cholera 
  or 
  Yellow 
  Fever 
  among 
  human 
  beings. 
  He 
  fully 
  allows 
  that 
  the 
  mortality 
  

   among 
  the 
  Chinch-bugs 
  was 
  contemporaneous 
  with 
  the 
  wet 
  weather; 
  but 
  he 
  will 
  

   have 
  it 
  that 
  it 
  was 
  not 
  the 
  wet 
  weather 
  that 
  killed 
  the 
  Bug, 
  as 
  we 
  common 
  folk 
  have 
  

   always 
  hitherto 
  believed, 
  but 
  that 
  it 
  was 
  his 
  newly-discovered 
  Epidemic 
  Disease. 
  

  

  This 
  matter 
  of 
  the 
  effect 
  of 
  meteorological 
  conditions 
  upon 
  the 
  chinch-bug 
  

   I 
  have 
  treated 
  of 
  in 
  some 
  detail 
  elsewhere 
  in 
  this 
  report, 
  and 
  need 
  not 
  dis- 
  

   cuss 
  here. 
  

  

  In 
  1869, 
  Doctor 
  Shimer, 
  in 
  the 
  Transactions 
  Illinois 
  State 
  Historical 
  So- 
  

   ciety, 
  Vol. 
  in, 
  pp. 
  275-281, 
  referred 
  again 
  to 
  the 
  chinch-bug 
  epidemic 
  of 
  1865, 
  

   and 
  discussed 
  at 
  some 
  length 
  the 
  inherent 
  probability 
  of 
  epidemic 
  diseases 
  

   among 
  the 
  lower 
  forms 
  of 
  life. 
  He 
  declared 
  that 
  the 
  causes 
  of 
  disease 
  among 
  

   insects 
  are 
  laudable 
  and 
  proper 
  objects 
  for 
  the 
  study 
  of 
  the 
  practical 
  ento- 
  

   mologist. 
  

  

  In 
  1879 
  the 
  chinch-bug 
  bulletin 
  issued 
  by 
  the 
  United 
  States 
  Department 
  

   of 
  the 
  Interior 
  contained 
  the 
  comments 
  of 
  Doctor 
  Thomas 
  (previously 
  

   quoted 
  ) 
  on 
  Doctor 
  Shimer's 
  observations. 
  

  

  Previous 
  to 
  this 
  Doctors 
  Riley 
  and 
  Le 
  Baron 
  had 
  each 
  fo^id 
  occasion 
  

   to 
  express 
  the 
  belief 
  that 
  little 
  hope 
  from 
  natural 
  enemies 
  of 
  the 
  chinch-bug 
  

   could 
  be 
  entertained. 
  

  

  In 
  1882, 
  Prof. 
  S. 
  A. 
  Forbes, 
  State 
  Entomologist 
  of 
  Illinois, 
  began 
  his 
  ob- 
  

  

  * 
  Walsh, 
  B. 
  D., 
  American 
  Entomologist, 
  Vol. 
  I, 
  p. 
  175 
  ( 
  1869). 
  

  

  