﻿97 
  

  

  carefully 
  dusted 
  behind 
  the 
  sheaths 
  of 
  the 
  leaves, 
  on 
  the 
  ground 
  

   among 
  the 
  chinch-bugs 
  themseh-es, 
  about 
  the 
  roots 
  of 
  the 
  corn, 
  etc., 
  

   and 
  the 
  whole 
  culture 
  mass 
  was 
  then 
  broken 
  up 
  and 
  sprinkled 
  among 
  

   the 
  bugs. 
  The 
  examinations 
  made 
  September 
  8, 
  13. 
  and 
  1^, 
  yielded 
  

   only 
  a 
  few 
  bugs 
  in 
  this 
  situation 
  dead 
  with 
  muscardine. 
  On 
  this 
  

   last 
  date, 
  however, 
  many 
  dead 
  were 
  found 
  among 
  the 
  grass 
  along 
  the 
  

   sides 
  of 
  the 
  corn 
  and 
  in 
  the 
  sorghum 
  adjacent, 
  a 
  large 
  proportion 
  of 
  

   them 
  covered 
  with 
  the 
  fungus 
  of 
  white 
  muscardine, 
  especially 
  on 
  

   the 
  damp 
  earth 
  in 
  the 
  sorghum 
  field, 
  where 
  it 
  was 
  estimated 
  that 
  one 
  

   such 
  fungus-covered 
  insect 
  might 
  be 
  found 
  on 
  an 
  average 
  for 
  every 
  

   six 
  inches 
  throughoiit 
  the 
  j)lot. 
  Additional 
  visits 
  made 
  September 
  

   23 
  and 
  30 
  gave 
  practically 
  identical 
  results. 
  

  

  The 
  general 
  inference 
  from 
  this 
  somewhat 
  prolix 
  account 
  confirms 
  

   that 
  often 
  previously 
  drawn, 
  to 
  the 
  effect 
  that 
  hot, 
  dry, 
  bright 
  weather, 
  

   such 
  as 
  here 
  described, 
  even 
  with 
  occasional 
  showers 
  and 
  storms, 
  will 
  

   not 
  permit 
  the 
  development 
  and 
  spread 
  of 
  the 
  so-called 
  white 
  mus- 
  

   cardine 
  disease 
  among 
  chinch-bugs 
  in 
  the 
  open 
  field, 
  whatever 
  may 
  

   be 
  the 
  crop 
  which 
  they 
  infest. 
  The 
  fact 
  is 
  to 
  be 
  especially 
  noted 
  

   that 
  adults 
  of 
  the 
  hibernating 
  generation 
  perished 
  during 
  the 
  period 
  

   covered 
  by 
  this 
  narration, 
  while 
  the 
  field 
  infested 
  by 
  them 
  was 
  being 
  

   frequently 
  and 
  profusely 
  treated 
  with 
  Sporotrichum 
  cultures 
  and 
  

   fungus-covered 
  bugs, 
  but 
  that 
  even 
  these 
  spent 
  adults 
  did 
  not 
  l)ecome 
  

   infected 
  to 
  anj' 
  appreciable 
  extent. 
  On 
  the 
  other 
  hand, 
  there 
  was 
  

   not 
  during 
  this 
  whole 
  season 
  any 
  weather 
  so 
  hot, 
  bright, 
  and 
  dry 
  as 
  

   to 
  put 
  a 
  comj)lete 
  stop 
  to 
  the 
  continuance 
  of 
  the 
  fungus 
  in 
  the 
  field; 
  

   but 
  it 
  was 
  always 
  present 
  in 
  some 
  obscure 
  form 
  at 
  least, 
  likely 
  to 
  in- 
  

   crease 
  with 
  change 
  of 
  conditions. 
  

  

  Inoculation 
  of 
  Dead 
  Chinch-hiij/s 
  trith 
  Sporotrichiiiii. 
  — 
  By 
  a 
  

   preliminary 
  experiment 
  tried 
  on 
  a 
  small 
  scale 
  July 
  26, 
  1895. 
  it 
  was 
  

   ascertained 
  that 
  SporulricJuim 
  f/Iobiiliferuui 
  might 
  be 
  grown 
  with 
  

   great 
  success 
  upon 
  dead 
  chinch-bugs 
  if 
  these 
  were 
  inoculated 
  imme- 
  

   diately 
  after 
  death 
  and 
  kept 
  under 
  conditions 
  suitable 
  to 
  the 
  develop- 
  

   ment 
  of 
  the 
  fungus. 
  To 
  carry 
  this 
  experiment 
  still 
  farther, 
  a 
  num- 
  

   ber 
  of 
  experiments 
  were 
  arranged 
  in 
  September, 
  1895. 
  Upon 
  moist- 
  

   ened 
  sand 
  in 
  the 
  bottom 
  of 
  four 
  tumblers 
  dead 
  bugs 
  were 
  distributed 
  

   and 
  covered 
  with 
  moist 
  filter 
  paper. 
  In 
  one 
  of 
  these 
  dishes 
  was 
  

   placed 
  a 
  lot 
  of 
  about 
  five 
  hundred 
  and 
  twenty 
  chinch-bugs 
  which 
  had 
  

   been 
  killed 
  in 
  vapor 
  of 
  cyanide 
  of 
  potassium 
  and 
  kept 
  exposed 
  con- 
  

   tinuously 
  to 
  this 
  vapor 
  for 
  about 
  twelve 
  hours. 
  In 
  a 
  second 
  experi- 
  

   ment 
  an 
  equal 
  number 
  of 
  chinch-bugs 
  were 
  placed 
  in 
  a 
  tumbler 
  

   after 
  al)out 
  three 
  hours' 
  exposure 
  to 
  the 
  vapor; 
  in 
  a 
  third, 
  after 
  one 
  

   hour; 
  and 
  in 
  a 
  fourth, 
  after 
  ten 
  minutes. 
  In 
  each 
  case 
  the 
  bugs 
  were 
  

   thoroughly 
  dusted 
  with 
  spores 
  from 
  a 
  ripe 
  culture 
  of 
  Sporotrichum 
  

   one 
  remove 
  from 
  an 
  infected 
  insect. 
  In 
  all 
  these 
  trials 
  Sporotrichum 
  

   grew 
  abundantly 
  upon 
  the 
  dead 
  insects, 
  in 
  one 
  case 
  every 
  bug 
  but 
  

   one 
  of 
  the 
  entire 
  lot 
  being 
  profusely 
  covered 
  with 
  a 
  fresh 
  growth. 
  A 
  

   few 
  bugs 
  revived 
  after 
  exposure 
  to 
  the 
  cyanide 
  in 
  all 
  the 
  lots 
  except 
  

   the 
  first, 
  nearly 
  two 
  thirds, 
  in 
  fact, 
  of 
  those 
  exposed 
  for 
  ten 
  minutes 
  

   recovering 
  sufficiently 
  to 
  crawl 
  about. 
  

   —7 
  

  

  