﻿92 
  

  

  ceding. 
  Among 
  the 
  great 
  number 
  of 
  chinch-bugs 
  contained 
  in 
  these 
  

   boxes 
  a 
  considerable 
  number 
  dead 
  with 
  Entomophthora 
  were 
  scat- 
  

   tered 
  Sei:)tember 
  l-i 
  on 
  the 
  damp 
  earth 
  among 
  the 
  living 
  bugs. 
  Fresh 
  

   food 
  was 
  at 
  the 
  same 
  time 
  introduced, 
  and 
  the 
  earth 
  in 
  the 
  bottom 
  of 
  

   the 
  boxes 
  moistened. 
  No 
  trace 
  of 
  an 
  extension 
  of 
  the 
  Entomoph- 
  

   thora 
  to 
  living 
  insects 
  was 
  seen 
  until 
  September 
  20, 
  when 
  a 
  single 
  

   specimen 
  was 
  found 
  dead 
  and 
  covered 
  with 
  a 
  fresh 
  growth 
  of 
  this 
  

   fungus. 
  Sporotrichum 
  was, 
  however, 
  increasing 
  in 
  both 
  the 
  boxes, 
  

   appearing 
  not 
  only 
  on 
  chinch-bugs, 
  but 
  on 
  other 
  insects 
  accidentally 
  

   introduced. 
  No 
  more 
  Entomophthora 
  was 
  seen 
  until 
  September 
  26, 
  

   when 
  two 
  bugs 
  were 
  found 
  dead 
  with 
  it, 
  one 
  in 
  each 
  box. 
  More 
  than 
  

   fifty 
  insects 
  in 
  the 
  meantime, 
  among 
  them 
  a 
  blow-fly 
  maggot, 
  had 
  

   produced 
  a 
  fresh 
  growth 
  of 
  Sporotrichum. 
  The 
  Entomophthora 
  at- 
  

   tack 
  had, 
  however, 
  increased 
  somewhat 
  by 
  the 
  28th, 
  when 
  about 
  a 
  

   dozen 
  insects 
  exhibited 
  a 
  profuse 
  growth 
  of 
  it, 
  some 
  of 
  them 
  on 
  the 
  

   ground 
  and 
  others 
  attached 
  to 
  leaves; 
  this 
  in 
  one 
  of 
  the 
  boxes 
  only. 
  

   By 
  September 
  30 
  this 
  appearance 
  had 
  died 
  away, 
  only 
  a 
  single 
  

   chinch-bug 
  being 
  found 
  dead 
  with 
  Entomophthora 
  on 
  that 
  day. 
  

  

  Sporotiichum 
  was, 
  however, 
  quite 
  abundant, 
  some 
  twenty-five 
  or 
  

   more 
  showing 
  fresh 
  growth. 
  October 
  9 
  the 
  Entomophthora 
  seemed 
  

   to 
  have 
  disappeared 
  entirely, 
  but 
  on 
  the 
  12th 
  it 
  had 
  appeared 
  again, 
  

   showing 
  a 
  good 
  growth 
  on 
  several 
  bugs, 
  specimens 
  covered 
  with 
  

   Sporotrichum 
  being 
  at 
  least 
  equally 
  common. 
  The 
  experiment 
  was 
  

   at 
  this 
  time 
  neglected, 
  the 
  contents 
  of 
  the 
  boxes 
  being 
  permitted 
  to 
  

   dry 
  out 
  and 
  to 
  remain 
  dry 
  until 
  November 
  30, 
  at 
  which 
  time 
  most 
  of 
  

   the 
  bugs 
  were 
  dead, 
  such 
  of 
  them 
  as 
  were 
  microscopically 
  examined 
  

   being 
  filled 
  with 
  a 
  fungus 
  mycelium. 
  Water 
  was 
  now 
  added, 
  with 
  the 
  

   effect 
  to 
  develop 
  a 
  few 
  days 
  later 
  a 
  good 
  growth 
  of 
  Sporotrichum 
  on 
  

   many 
  of 
  the 
  bugs, 
  but 
  none 
  at 
  all 
  of 
  Entomophthora. 
  

  

  There 
  is 
  a 
  suggestion 
  of 
  periodicity 
  in 
  these 
  results 
  which 
  leads 
  me 
  

   to 
  suppose 
  that 
  the 
  coming 
  and 
  going 
  of 
  the 
  fungus 
  in 
  these 
  boxes 
  

   is 
  to 
  be 
  connected 
  with 
  the 
  period 
  of 
  incubation 
  between 
  the 
  ripening 
  

   of 
  the 
  spores 
  and 
  the 
  growth 
  and 
  fruiting 
  of 
  the 
  plant 
  anew. 
  The 
  

   first 
  and 
  second 
  of 
  such 
  intervals 
  seem 
  to 
  have 
  been 
  six 
  days 
  After 
  

   the 
  second 
  interval, 
  for 
  a 
  period 
  of 
  eight 
  days, 
  from 
  October 
  1 
  to 
  9, 
  

   the 
  contents 
  of 
  the 
  box 
  were 
  not 
  watered, 
  and 
  it 
  is 
  to 
  this 
  fact, 
  per- 
  

   haps, 
  that 
  the 
  long 
  interval 
  of 
  fourteen 
  to 
  sixteen 
  days, 
  running 
  to 
  

   October 
  12, 
  is 
  to 
  be 
  attributed. 
  During 
  the 
  next 
  month 
  the 
  contents 
  

   of 
  the 
  box 
  dried 
  out 
  completely, 
  this 
  treatment 
  apparently 
  killing 
  

   the 
  Entomophthora, 
  as 
  it 
  did 
  not 
  revive 
  upon 
  the 
  addition 
  of 
  water 
  

   Noveml)er 
  30. 
  Sporotrichum 
  was, 
  however, 
  much 
  more 
  persistent 
  in 
  

   this 
  experiment, 
  and 
  evidently 
  attacked 
  from 
  beginningto 
  end 
  a 
  larger 
  

   number 
  of 
  bugs 
  than 
  did 
  the 
  Entomophthora. 
  Although 
  this 
  Sporo- 
  

   trichum 
  had 
  not 
  been 
  experimentally 
  introduced 
  in 
  the 
  beginning, 
  

   its 
  presence 
  among 
  the 
  chinch-bugs 
  used 
  in 
  the 
  experiment 
  had 
  al- 
  

   ready 
  been 
  noted. 
  

  

  Field 
  Expcriiiicnis 
  with 
  White 
  Muscardine 
  Fungus 
  {Sporo- 
  

   trichum 
  (jlohiilifcru.m) 
  on 
  ChincJt-bugn. 
  — 
  The 
  occurrence 
  in 
  1895 
  of 
  

   the 
  chinch-bug 
  in 
  moderate 
  numbers 
  in 
  a 
  field 
  of 
  wheat 
  on 
  the 
  Ex- 
  

   periment 
  Station 
  premises, 
  at 
  a 
  distance 
  of 
  a 
  quarter 
  of 
  a 
  mile 
  from 
  

  

  