﻿80 
  

  

  and 
  that 
  the 
  oflPect 
  of 
  the 
  same 
  temperatures 
  in 
  dry 
  air 
  was 
  not 
  very 
  

   materially 
  different. 
  Careful 
  observations 
  of 
  temperatures 
  in 
  all 
  out- 
  

   door 
  situations 
  where 
  chinch-bugs 
  are 
  likely 
  to 
  iiarbor 
  in 
  the 
  hottest 
  

   midsummer 
  days, 
  gave 
  no 
  such 
  fatal 
  temperatures. 
  It 
  seemed 
  

   l^ossible, 
  however, 
  that 
  chinch-bugs' 
  eggs 
  might 
  be 
  destroyed 
  by 
  mid- 
  

   summer 
  heat, 
  even 
  when 
  concealed 
  by 
  clods 
  of 
  earth 
  of 
  considerable 
  

   size. 
  

  

  Experiments 
  with 
  the 
  eggs 
  of 
  these 
  insects 
  show 
  that 
  they 
  will 
  

   hatch 
  without 
  loss 
  if 
  kept 
  coutituiousl}'' 
  submerged 
  in 
  water 
  from 
  the 
  

   time 
  that 
  they 
  were 
  laid, 
  but 
  that 
  the 
  young 
  hatching 
  under 
  water 
  

   will 
  almost 
  invariably 
  drown; 
  that 
  eggs 
  may 
  also 
  hatch 
  if 
  kept 
  con- 
  

   tinuously 
  in 
  a 
  saturated 
  atmosphere, 
  but 
  that 
  a 
  large 
  percentage 
  may 
  

   fail 
  under 
  these 
  conditions 
  and 
  that 
  the 
  freshly 
  hatched 
  young 
  uiay 
  

   drown 
  ; 
  and 
  that 
  ke[)t 
  continuously 
  in 
  very 
  dry 
  air 
  the 
  eggs 
  may 
  fail 
  to 
  

   hatch 
  almost 
  entirely, 
  large 
  numbers 
  of 
  the 
  young 
  not 
  succeeding 
  in 
  

   freeing 
  themselves 
  fully 
  from 
  the 
  shell. 
  Drouth 
  of 
  this 
  degree, 
  how- 
  

   ever, 
  is 
  probably 
  never 
  experienced 
  in 
  the 
  held. 
  

  

  Contrary 
  to 
  an 
  earlier 
  conclusion 
  it 
  was 
  proven 
  that 
  eggs 
  of 
  chinch- 
  

   bugs 
  are 
  but 
  little 
  susceptible 
  to 
  infection 
  by 
  the 
  muscardine 
  fuugi^ 
  

   S[)orotrichum 
  being, 
  however, 
  more 
  effective 
  than 
  Entomophthora, 
  

   This 
  latter 
  fungus 
  was 
  shown 
  t(i 
  spread 
  among 
  bugs 
  in 
  confinement 
  

   slowly 
  and 
  imperfectly, 
  less 
  actively 
  indeed 
  tlian 
  Sporotrichum, 
  A 
  

   field 
  experiment 
  confirmed 
  again 
  the 
  already 
  frequently 
  repeated 
  

   conclusion 
  that 
  hot 
  and 
  dry 
  weather 
  prevents 
  the 
  spread 
  of 
  white- 
  

   muscardine 
  in 
  the 
  field, 
  but 
  showed 
  also 
  that 
  the 
  fungus 
  of 
  this 
  dis- 
  

   ease 
  manages 
  to 
  persist, 
  in 
  a 
  small 
  way, 
  here 
  and 
  there, 
  under 
  general 
  

   conditions 
  extremely 
  unfavorably 
  to 
  it. 
  

  

  An 
  instructive 
  series 
  of 
  laboratory 
  experiments 
  showed 
  that 
  the 
  

   fungus 
  of 
  white 
  muscardine 
  can 
  be 
  grown 
  very 
  readily 
  upon 
  the 
  

   dead 
  bodies 
  of 
  chinch-bugs 
  freshly 
  killed 
  if 
  these 
  are 
  well 
  infected 
  

   immediately 
  after 
  death 
  and 
  kept 
  under 
  conditions 
  of 
  temperature 
  

   and 
  moisture 
  favorable 
  to 
  the 
  growth 
  of 
  the 
  fungus. 
  This 
  is 
  a 
  point 
  

   of 
  some 
  practical 
  interest, 
  since 
  it 
  suggests 
  a 
  p')sslbi!ity 
  that 
  chinch- 
  

   bugs 
  found 
  dead 
  in 
  the 
  field 
  and 
  covered 
  with 
  the 
  fungus 
  of 
  mus- 
  

   cardine 
  may 
  not 
  always 
  have 
  been 
  killed 
  by 
  it, 
  but 
  may 
  have 
  grown 
  

   it 
  as 
  a 
  consequence 
  of 
  posl-morlon 
  infection. 
  

  

  Tt 
  is 
  also 
  clearly 
  shown 
  by 
  these 
  experiments 
  that 
  cliinch-bugs 
  can- 
  

   not 
  be 
  killed 
  in 
  early 
  spring 
  in 
  their 
  winter 
  quarters 
  by 
  burning 
  over 
  

   a 
  grassy 
  turf 
  in 
  which 
  they 
  have 
  sought 
  shelter 
  for 
  hibernation. 
  

  

  The 
  burial 
  of 
  chinch-bugs' 
  egus 
  by 
  plowing 
  and 
  rolling 
  was 
  imitated 
  

   by 
  a 
  laboratory 
  experiment 
  with 
  the 
  effect 
  to 
  prev(Mit 
  the 
  hatching 
  of 
  

   from 
  one 
  fifth 
  to 
  one 
  fourth 
  of 
  them 
  when 
  buried 
  to 
  a 
  (le[)th 
  of 
  two 
  

   to 
  four 
  inches. 
  

  

  It 
  is 
  also 
  shown 
  that 
  salt 
  ai>plie(l 
  to 
  soil 
  and 
  mixed 
  with 
  it 
  to 
  the- 
  

   amount 
  ef 
  twenty 
  ])er 
  cent, 
  pao 
  lu(;ed 
  no 
  elfet-t 
  up'iii 
  th(> 
  tiatching 
  of 
  

   c1\inch-bugs' 
  eggs 
  distributetl 
  through 
  the 
  eartii. 
  

  

  K.rpcriiiiciif^ 
  on 
  Ci'Dijxn-dtivc 
  V^ilalihi 
  of 
  HihcrNnfin;/ 
  Chiiirh- 
  

   h>i(jx. 
  — 
  On 
  ])au:e 
  1::)7 
  of 
  my 
  Eighth 
  Rep 
  irt 
  it 
  is 
  sho\tn 
  that 
  adult 
  

   chinch-buiis 
  of 
  the 
  midsummer 
  generation 
  may 
  live 
  floating 
  u[)on 
  

  

  