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  CONTAGIOUS 
  DISEASES 
  OF 
  THE 
  CHINCH-BUG. 
  

  

  Illinois 
  State 
  Horticultural 
  Society 
  for 
  1880, 
  Dr. 
  Thomas 
  accounts 
  for 
  the 
  

   oscillations 
  of 
  injurious 
  insects 
  by 
  reference 
  to 
  meteorological 
  conditions, 
  

   considering 
  that 
  years 
  of 
  greatest 
  drouth 
  are 
  generally 
  marked 
  by 
  unusual 
  

   development 
  of 
  insect 
  life. 
  He 
  believes 
  that 
  as 
  a 
  rule 
  two 
  consecutive 
  dry 
  

   seasons 
  are 
  necessary 
  to 
  great 
  development 
  of 
  most 
  injurious 
  species. 
  

  

  Dr. 
  C. 
  V. 
  Riley, 
  writing 
  on 
  the 
  chinch-bug, 
  in 
  the 
  American 
  Agriculturist 
  

   for 
  November 
  and 
  December, 
  1881, 
  says 
  that 
  heavy 
  rains, 
  wet 
  seasons, 
  and 
  

   warm, 
  moist 
  or 
  open 
  winters 
  are 
  very 
  prejudicial 
  to 
  the 
  pest. 
  

  

  In 
  1882, 
  Prof 
  S. 
  A. 
  Forbes, 
  State 
  Entomologist 
  of 
  Illinois, 
  struck 
  the 
  first 
  

   note 
  of 
  doubt 
  concerning 
  the 
  supposed 
  efficacy 
  of 
  wet 
  weather 
  in 
  holding 
  the 
  

   chinch-bug 
  in 
  check. 
  In 
  an 
  article, 
  "The 
  Chinch-bug 
  in 
  1882, 
  Field 
  Notes," 
  

   sent 
  as 
  part 
  of 
  the 
  Illinois 
  crop 
  reports 
  to 
  the 
  United 
  States 
  Department 
  of 
  

   Agriculture, 
  August 
  1, 
  1882, 
  and 
  printed 
  in 
  Circular 
  No. 
  92 
  of 
  the 
  depart- 
  

   ment, 
  Professor 
  Forbes 
  declares 
  that 
  careful 
  experiments 
  seem 
  -to 
  show 
  that 
  

   too 
  much 
  is 
  hoped 
  from 
  the 
  simple 
  influence 
  of 
  wet 
  weather 
  upon 
  these 
  in- 
  

   sects. 
  Bugs 
  in 
  corn 
  drenched 
  10 
  successive 
  days 
  were 
  not 
  affected 
  appreci- 
  

   ably. 
  Prof. 
  E. 
  A. 
  Popenoe, 
  of 
  the 
  Kansas 
  State 
  Agricultural 
  College, 
  in 
  an 
  

   article 
  in 
  the 
  Prairie 
  Farmer 
  for 
  November 
  25, 
  1882, 
  thinks 
  it 
  possible 
  that 
  

   simple 
  excess 
  of 
  moisture 
  drowns 
  young 
  bugs 
  on 
  the 
  ground, 
  but 
  doubts 
  if 
  

   others 
  are 
  so 
  affected. 
  Mr. 
  J. 
  I. 
  Johnson, 
  in 
  the 
  Transactions 
  of 
  the 
  Illinois 
  

   State 
  Horticultural 
  Society 
  for 
  1881 
  (published 
  in 
  1882), 
  records 
  that 
  he 
  

   has 
  held 
  chinch-bugs 
  in 
  water 
  for 
  more 
  than 
  an 
  hour 
  without 
  injuring 
  them. 
  

   Dr. 
  J. 
  A. 
  Lintner, 
  State 
  Entomologist 
  of 
  New 
  York, 
  in 
  an 
  article 
  in 
  Science 
  

   for 
  October 
  13, 
  1883, 
  reports 
  a 
  serious 
  chinch-bug 
  attack 
  in 
  New 
  York, 
  and 
  

   says 
  that 
  the 
  attack 
  continues 
  to 
  increase 
  notwithstanding 
  wet 
  weather 
  of 
  last 
  

   year 
  (1882), 
  and 
  this 
  (1883). 
  Doctor 
  Riley, 
  writing 
  to 
  Science 
  soon 
  after, 
  

   attributed 
  the 
  apparent 
  lack 
  of 
  susceptibility 
  of 
  the 
  New 
  York 
  chinch-bugs 
  

   to 
  wet 
  weather 
  to 
  the 
  excessive 
  multiplication 
  of 
  the 
  insect 
  during 
  the 
  very 
  

   dry 
  seasons 
  of 
  1880 
  and 
  1881, 
  and 
  the 
  ability 
  of 
  the 
  bugs, 
  already 
  deter- 
  

   mined 
  in 
  the 
  West, 
  to 
  brave 
  unfavorable 
  weather 
  for 
  a 
  time. 
  He 
  thinks 
  that 
  

   the 
  wet 
  weather 
  will 
  tell, 
  however, 
  on 
  the 
  hibernating 
  bugs. 
  In 
  the 
  Twelfth 
  

   Report 
  of 
  the 
  State 
  Entomologist 
  of 
  Illinois 
  ( 
  1882 
  ), 
  Professor 
  Forbes, 
  in 
  dis- 
  

   cussing 
  the 
  history 
  of 
  the 
  chinch-bug 
  in 
  Illinois 
  for 
  the 
  year, 
  says 
  (page 
  39): 
  

  

  That 
  the 
  almost 
  complete 
  destruction 
  or 
  suppression 
  of 
  the 
  spring 
  brood 
  was 
  

   due 
  to 
  the 
  prolonged 
  and 
  violent 
  rains, 
  there 
  can 
  be 
  no 
  reasonable 
  doubt. 
  The 
  ex- 
  

   act 
  method 
  in 
  -which 
  rainy 
  weather 
  affects 
  the 
  bugs 
  is, 
  however, 
  as 
  yet 
  undecided. 
  

   That 
  it 
  cannot 
  be 
  simple 
  submergence 
  that 
  destroys 
  them, 
  is 
  shown 
  by 
  a 
  fact 
  re- 
  

   ported 
  to 
  me 
  by 
  Hon. 
  Wm. 
  McAdams. 
  In 
  his 
  vicinity, 
  in 
  Jersey 
  county, 
  they 
  were 
  

   extremely 
  abundant 
  in 
  the 
  grain 
  in 
  the 
  spring, 
  but 
  were 
  all 
  apparently 
  swept 
  out 
  

   of 
  the 
  country 
  by 
  a 
  long 
  and 
  violent 
  storm. 
  Some 
  days 
  afterwards, 
  wheri 
  the 
  water 
  

   had 
  subsided, 
  he 
  noticed 
  in 
  pulling 
  over 
  the 
  drift-wood 
  in 
  the 
  river 
  bottoms 
  im- 
  

   mense 
  numbers 
  of 
  chinch-bugs 
  among 
  the 
  rubbish, 
  most 
  of 
  them 
  still 
  alive 
  and 
  

   crawling 
  about. 
  On 
  the 
  other 
  hand, 
  it 
  seems 
  unlikely 
  that 
  simple 
  exposure 
  to 
  

   moisture 
  has 
  the 
  effect 
  attributed 
  to 
  rain. 
  An 
  experiment 
  made 
  at 
  the 
  laboratory 
  

   bears 
  upon 
  this 
  question 
  and 
  will 
  be 
  worth 
  reporting, 
  although 
  circumstances 
  pre- 
  

   vented 
  its 
  satisfactory 
  completion. 
  A 
  number 
  of 
  hills 
  infested 
  by 
  the 
  bugs 
  were 
  

  

  