﻿MISCELLANEOUS 
  CHINCH-BUG 
  EXPERIMENTS. 
  

  

  I 
  have 
  next 
  to 
  report 
  a 
  considerable 
  number 
  of 
  miscellaneous 
  ex- 
  

   periments 
  on 
  chinch-bugs 
  carried 
  on 
  from 
  my 
  office 
  in 
  the 
  year 
  1895, 
  

   the 
  object 
  of 
  which 
  was 
  either 
  to 
  verify 
  earlier 
  experiments 
  or 
  to 
  

   settle 
  new 
  points 
  in 
  the 
  economy 
  of 
  these 
  insects. 
  

  

  Some 
  of 
  these 
  experiments 
  related 
  to 
  the 
  vitality 
  of 
  the 
  hibernating 
  

   generation 
  of 
  the 
  chinch-bug 
  as 
  compared 
  with 
  the 
  midsummer 
  gen- 
  

   eration, 
  with 
  especial 
  reference 
  to 
  the 
  possibility 
  of 
  introducing 
  con- 
  

   tagious 
  disease 
  among 
  this 
  hibernating 
  generation 
  while 
  concentrated 
  

   in 
  their 
  winter 
  quarters, 
  just 
  before 
  the 
  spring 
  dispersal. 
  I 
  thought 
  

   it 
  possible 
  that 
  the 
  much 
  longer 
  life 
  of 
  this 
  generation 
  and 
  its 
  ex- 
  

   posure 
  to 
  the 
  vicissitudes 
  of 
  hibernation 
  might 
  so 
  reduce 
  its 
  vigor 
  as 
  

   to 
  make 
  it 
  more 
  liable 
  than 
  the 
  generation 
  next 
  to 
  follow 
  to 
  injury 
  by 
  

   rains 
  and 
  drouth 
  and 
  by 
  the 
  attack 
  of 
  its 
  muscardine 
  parasites. 
  The 
  

   results 
  of 
  the 
  experiments 
  give, 
  however, 
  no 
  support 
  to 
  this 
  hypoth- 
  

   esis. 
  On 
  the 
  contrary, 
  hibernating 
  chinch-bugs 
  immersed 
  contin- 
  

   uously 
  in 
  water, 
  confined 
  in 
  a 
  saturated 
  atmosphere, 
  or 
  exposed 
  to 
  

   death 
  by 
  drouth 
  or 
  by 
  starvation, 
  showed 
  powers 
  of 
  resistance 
  prac- 
  

   tically 
  equal 
  to 
  those 
  of 
  the 
  midsummer 
  generation, 
  as 
  these 
  had 
  been 
  

   determined 
  by 
  my 
  experiments 
  of 
  previous 
  years. 
  

  

  Attempts 
  to 
  introduce 
  the 
  contagious 
  disease 
  known 
  as 
  white 
  mus- 
  

   cardine 
  among 
  hibernating 
  chinch-bugs 
  completely 
  failed 
  so 
  far 
  as 
  

   could 
  be 
  seen, 
  owing 
  iDrimarily 
  to 
  the 
  fact, 
  learned 
  in 
  the 
  course 
  of 
  these 
  

   experiments, 
  that 
  the 
  fungus 
  of 
  this 
  disease 
  would 
  neither 
  germinate 
  

   nor 
  grow 
  in 
  the 
  hibernating 
  quarters 
  of 
  the 
  chinch-bug 
  until 
  the 
  

   weather 
  had 
  warmetl 
  sufficiently 
  to 
  lead 
  the 
  bugs 
  to 
  abandon 
  them 
  

   for 
  the 
  fields 
  of 
  growing 
  grain. 
  The 
  beginning 
  of 
  growth 
  of 
  the 
  

   muscardine 
  fungus 
  at 
  outdoor 
  temperatures 
  in 
  jars 
  placed 
  on 
  the 
  

   ground 
  was, 
  in 
  fact, 
  quite 
  simultaneous 
  with 
  the 
  spring 
  disjjersal 
  of 
  

   the 
  bug. 
  It 
  is 
  i30ssible, 
  of 
  course, 
  that 
  the 
  muscardine 
  infection 
  was 
  

   conveyed 
  to 
  the 
  field 
  by 
  these 
  scattering 
  bugs, 
  to 
  take 
  effect 
  there 
  

   later; 
  but 
  I 
  have 
  no 
  definite 
  evidence 
  to 
  that 
  effect. 
  

  

  Another 
  series 
  of 
  experiments 
  was 
  intended 
  to 
  test 
  the 
  possibility 
  

   of 
  the 
  destruction 
  of 
  chinch-bugs 
  under 
  natural 
  conditions 
  in 
  the 
  

   fields 
  by 
  extreme 
  midsummer 
  heat. 
  Here, 
  also, 
  the 
  results 
  were 
  mainly 
  

   negative. 
  It 
  was 
  found 
  by 
  laboratory 
  experimentation 
  that 
  a 
  moist 
  

   heat 
  of 
  117^ 
  applied 
  continuously 
  for 
  twenty 
  hours, 
  of 
  119" 
  for 
  six 
  

   hours, 
  and 
  of 
  120" 
  to 
  122" 
  for 
  two 
  hours 
  was 
  fatal 
  to 
  chinch-bugs; 
  

  

  