﻿HISTORY 
  OF 
  THE 
  DISEASES 
  IN 
  THE 
  UNITED 
  STATES. 
  213 
  

  

  of 
  Sporotrichum 
  from 
  their 
  bodies. 
  Unfortunately, 
  however, 
  for 
  the 
  significance 
  

   of 
  these 
  results, 
  six 
  specimens 
  from 
  the 
  check 
  of 
  30 
  originally 
  separated 
  had 
  per- 
  

   ished 
  in 
  the 
  same 
  manner, 
  thus 
  giving 
  evidence 
  either 
  that 
  the 
  original 
  lot, 
  obtained 
  

   from 
  Litchfield, 
  Montgomery 
  county, 
  had 
  been 
  diseased 
  when 
  taken, 
  or 
  else 
  that 
  

   the 
  check 
  had 
  become 
  infected 
  from 
  the 
  neighboring 
  experimental 
  lots. 
  

  

  Similar 
  experiments 
  on 
  other 
  insects 
  were 
  tried 
  with 
  similar 
  results. 
  Saw-fly 
  

   larva? 
  (Tenthredinidce), 
  obtained 
  by 
  sweeping 
  from 
  grass 
  May 
  22d, 
  were 
  dusted 
  with 
  

   spores 
  from 
  the 
  Thaxter 
  culture 
  and 
  placed 
  under 
  a 
  bell 
  glass 
  on 
  growing 
  blue-grass 
  

   and 
  clover. 
  On 
  the 
  26th 
  two 
  larvae 
  were 
  dead 
  and 
  covered 
  with 
  the 
  fungus, 
  together 
  

   with 
  a 
  small 
  fly 
  (Dolichopodidce) 
  accidentally 
  enclosed 
  with 
  them. 
  May 
  28 
  more 
  

   larva? 
  were 
  affected, 
  and 
  by 
  the 
  30th 
  all 
  were 
  dead. 
  In 
  the 
  same 
  lot 
  were 
  larvae 
  of 
  

   Apatura 
  and 
  several 
  plant 
  lice, 
  all 
  of 
  which 
  died 
  in 
  the 
  same 
  manner. 
  Saw-fly 
  larva? 
  

   enclosed 
  without 
  treatment 
  had 
  all 
  survived. 
  

  

  Plant 
  lice, 
  obtained 
  by 
  sweeping 
  fields 
  of 
  clover, 
  were 
  similarly 
  treated 
  May 
  25, 
  

   and 
  enclosed 
  on 
  clover 
  plants 
  within 
  a 
  glass 
  cylinder 
  open 
  at 
  the 
  top. 
  June 
  1 
  

   some 
  of 
  the 
  plant 
  lice 
  seemed 
  weak 
  and 
  wandered 
  from 
  their 
  food, 
  and 
  two 
  days 
  later 
  

   all 
  were 
  dead 
  and 
  covered 
  with 
  the 
  fungus. 
  In 
  the 
  check 
  lot, 
  meantime, 
  a 
  few 
  had 
  

   died, 
  but 
  none 
  developed 
  the 
  fungus 
  either 
  then 
  or 
  thereafter. 
  Most, 
  however, 
  were 
  

   alive. 
  

  

  Ten 
  larva? 
  of 
  saw-flies 
  and 
  of 
  Lepidoptera, 
  taken 
  in 
  sweeping, 
  were 
  placed, 
  May 
  

   22, 
  under 
  a 
  bell 
  glass 
  with 
  grass 
  and 
  clover, 
  and 
  well 
  dusted 
  with 
  spores 
  from 
  the 
  

   Thaxter 
  culture 
  tube. 
  On 
  the 
  25th 
  of 
  May, 
  the 
  Sporotrichum 
  had 
  begun 
  to 
  show 
  on 
  

   two 
  of 
  the 
  larva?. 
  May 
  27 
  several 
  more 
  were 
  dead, 
  with 
  the 
  development 
  of 
  spores, 
  

   and 
  by 
  June 
  4 
  all 
  had 
  similarly 
  perished. 
  

  

  June 
  1 
  eight 
  Cecropia 
  moths 
  were 
  dusted 
  with 
  Sporotrichum 
  spores 
  and 
  placed 
  

   in 
  a 
  breeding 
  cage 
  over 
  damp 
  earth. 
  Two 
  days 
  later 
  two 
  of 
  the 
  moths 
  were 
  dead, 
  

   and 
  June 
  8 
  all 
  had 
  died; 
  but 
  it 
  was 
  not 
  until 
  the 
  12th 
  that 
  the 
  spores 
  appeared 
  ex- 
  

   ternally. 
  

  

  It 
  seems 
  clear, 
  from 
  the 
  foregoing, 
  that 
  Sporotrichum 
  globuliferum 
  is 
  an 
  entomogen- 
  

   ous 
  fungus 
  capable 
  of 
  attacking 
  healthy 
  insects 
  in 
  great 
  variety, 
  young 
  and 
  old; 
  that 
  

   it 
  may 
  take 
  first 
  effect 
  in 
  about 
  two 
  days, 
  but 
  that 
  mature 
  spores 
  will 
  be 
  9 
  or 
  10 
  days 
  

   in 
  forming. 
  Experiments 
  not 
  here 
  reported 
  have 
  satisfied 
  me 
  that, 
  although 
  the 
  

   fungus 
  may 
  be 
  successfully 
  transferred 
  to 
  culture 
  media 
  in 
  any 
  stage, 
  the 
  complete 
  

   maturity 
  of 
  the 
  spores 
  is 
  probably 
  necessary 
  to 
  the 
  infection 
  of 
  living 
  insects. 
  It 
  

   may 
  be 
  readily 
  grown 
  by 
  the 
  methods 
  of 
  sterile 
  culture, 
  on 
  agar 
  or 
  on 
  almost 
  any 
  

   substance 
  soaked 
  with 
  sterilized 
  beef 
  broth, 
  and 
  cultures 
  so 
  produced 
  may 
  be 
  used 
  

   to 
  infect 
  insects. 
  On 
  the 
  other 
  hand, 
  this 
  seems 
  not 
  to 
  be 
  a 
  very 
  virulent 
  insect 
  para- 
  

   site, 
  and 
  I 
  am 
  not 
  as 
  yet 
  at 
  all 
  certain 
  that 
  it 
  will 
  be 
  found 
  especially 
  useful 
  to 
  the 
  

   economic 
  entomologist, 
  except 
  where 
  both 
  meteorological 
  and 
  entomological 
  condi- 
  

   tions 
  unite 
  to 
  favor 
  its 
  growth 
  and 
  rapid 
  spread. 
  

  

  In 
  the 
  North 
  American 
  Practitioner 
  for 
  September, 
  1891, 
  Professor 
  Forbes 
  

   published 
  a 
  paper, 
  "On 
  a 
  Bacterial 
  Insect 
  Disease." 
  He 
  presents 
  a 
  careful 
  

   anatomical 
  description 
  of 
  the 
  alimentary 
  canal 
  of 
  the 
  chinch-bug, 
  calling 
  es- 
  

   pecial 
  attention 
  to 
  a 
  whorl 
  of 
  eight 
  coeca, 
  or 
  stomachic 
  appendages: 
  

  

  The 
  coeca, 
  radically 
  arranged, 
  are 
  about 
  .12 
  mm. 
  in 
  diameter, 
  and 
  average 
  1.5 
  mm. 
  

   in 
  length. 
  They 
  are 
  straight 
  or 
  slightly 
  contorted, 
  with 
  smoothly-rounded 
  ends, 
  and 
  

   are 
  nearly 
  filled, 
  when 
  in 
  normal 
  condition, 
  with 
  large 
  pole 
  loosely 
  attached; 
  sub- 
  

   spherical 
  cells, 
  similar 
  to 
  those 
  of 
  the 
  gastric 
  epithelium, 
  but 
  containing 
  more 
  fatty 
  

   granules. 
  These 
  cells 
  are 
  variable 
  in 
  size, 
  and 
  individual^ 
  ones 
  become 
  greatly 
  swol- 
  

   len, 
  and 
  probably 
  break 
  down 
  in 
  secretion. 
  The 
  lumen 
  of 
  the 
  tube 
  is 
  an 
  irregular 
  

   linear 
  space, 
  not 
  readily 
  distinguishable 
  in 
  the 
  midst 
  of^the 
  cells. 
  . 
  . 
  . 
  Curiously 
  

   —14 
  

  

  