﻿50 
  

  

  living 
  chinch-bugs 
  iu 
  considcrabh' 
  nunihcr. 
  the 
  iornicr 
  for 
  care- 
  

   ful 
  examination 
  with 
  reference 
  to 
  the 
  i^ossible 
  causes 
  of 
  death, 
  and 
  

   the 
  latter 
  for 
  continuous 
  observation 
  at 
  the 
  laboratory 
  and 
  for 
  ex- 
  

   perimental 
  use 
  in 
  determining 
  the 
  rate 
  of 
  death, 
  the 
  causes 
  thereof, 
  

   the 
  stages 
  in 
  which 
  dcatlis 
  were 
  occurring, 
  and 
  other 
  matters 
  of 
  

   kindred 
  interest. 
  

  

  The 
  living 
  specimens 
  thus 
  brought 
  in 
  from 
  time 
  to 
  lime 
  were 
  kept 
  

   under 
  conditions 
  as 
  nearly 
  normal 
  as 
  many 
  years' 
  experience 
  enabled 
  

   us 
  to 
  supply, 
  and 
  the 
  dead 
  were 
  removed 
  from 
  each 
  collection 
  day 
  

   by 
  day, 
  those 
  whose 
  bodies 
  gave 
  no 
  obvious 
  clue 
  to 
  the 
  cause 
  of 
  

   death' 
  being 
  commonly 
  placed 
  on 
  moist 
  sand 
  under 
  conditions 
  to 
  

   promote 
  the 
  external 
  development 
  of 
  any 
  infesting 
  fungus 
  to 
  whose 
  

   attacks 
  they 
  might 
  have 
  succumbed. 
  It 
  scarcely 
  need 
  be 
  said 
  that 
  

   these 
  collections 
  were 
  carefully 
  watched 
  and 
  laboriously 
  searched 
  

   with 
  the 
  microscope 
  for 
  evidences 
  of 
  disease 
  other 
  tlian 
  the 
  two 
  con- 
  

   tagious 
  diseases 
  definitely 
  known 
  to 
  prevail 
  among 
  these 
  itisects. 
  

  

  THE 
  DISTRICT 
  AS 
  A 
  WHOLE. 
  

  

  Taking 
  the 
  district 
  under 
  ol)servation 
  as 
  a 
  whole, 
  it 
  appears 
  from 
  

   the 
  data 
  herewith 
  presented 
  that 
  the 
  bugs 
  l)egan 
  to 
  leave 
  their 
  win- 
  

   ter 
  quarters 
  about 
  the 
  middle 
  of 
  April, 
  and 
  were 
  generally 
  distributed 
  

   to 
  their 
  breeding 
  and 
  feeding 
  grounds 
  —mainly 
  in 
  wheat 
  and 
  rye 
  — 
  

   ])y 
  the 
  end 
  of 
  that 
  month, 
  laying 
  of 
  eggs 
  beginning 
  before 
  the 
  first 
  

   of 
  May. 
  The 
  eggs 
  began 
  to 
  hatch 
  about 
  the 
  middle 
  of 
  that 
  month. 
  

   ])y 
  which 
  time 
  also 
  the 
  hibernating 
  adults 
  were 
  dying 
  (most 
  of 
  them 
  

   probably 
  in 
  the 
  normal 
  course 
  of 
  events). 
  In 
  some 
  cases 
  by 
  the 
  end 
  

   of 
  May, 
  and 
  in 
  others 
  not 
  till 
  the 
  middle 
  of 
  June, 
  these 
  old 
  adults 
  

   had 
  practically 
  all 
  disappeared. 
  Deaths 
  in 
  winter 
  quarters 
  varied 
  

   greatly, 
  from 
  twenty-five 
  per 
  cent., 
  as 
  at 
  Trbaiia, 
  to 
  almost 
  nothing, 
  

   as 
  at 
  Odin. 
  

  

  The 
  common 
  fungus 
  of 
  white 
  muscardine 
  was 
  everywhere 
  present 
  

   iu 
  winter 
  ([uarters 
  and 
  among 
  the 
  earliest 
  bugs 
  to 
  infest 
  the 
  wheat, 
  

   in 
  small 
  quantity, 
  it 
  is 
  true, 
  but 
  apparently 
  always 
  sufficient 
  to 
  fur- 
  

   nish 
  a 
  start 
  for 
  the 
  rapid 
  develojHnent 
  of 
  this 
  fungus 
  if 
  conditions, 
  

   meteorological 
  and 
  other, 
  should 
  become 
  favorable 
  to 
  its 
  germination 
  

   and 
  growth. 
  The 
  green 
  muscardine. 
  on 
  the 
  other 
  hand, 
  was 
  not 
  ob- 
  

   served 
  in 
  winter 
  cpiarters 
  anywhere, 
  and 
  appeared 
  in 
  the 
  fields 
  later 
  

   than 
  the 
  other, 
  usually 
  not 
  until 
  June. 
  At 
  Trbana. 
  however, 
  both 
  

   Hrst 
  appeared 
  together 
  about 
  the 
  middle 
  of 
  May. 
  Both 
  these 
  fungus 
  

   parasites 
  were 
  powerfully 
  affected 
  by 
  the 
  weather, 
  evidently 
  recpiir- 
  

   ing 
  a 
  moist 
  atmosphere 
  for 
  their 
  growth. 
  I 
  saw 
  nothing 
  in 
  our 
  ob- 
  

   servations 
  and 
  experinn^nts 
  to 
  indicate 
  that 
  one 
  is 
  any 
  more 
  virulent 
  

   as 
  a 
  parasite 
  than 
  the 
  other,* 
  although 
  we 
  have 
  no 
  evidence 
  that 
  the 
  

   fungus 
  of 
  green 
  muscardine 
  ( 
  Entomophthora) 
  will 
  take 
  its 
  start 
  upon 
  

   the 
  insect 
  body 
  already 
  dead. 
  The 
  wliite 
  fungus, 
  on 
  the 
  other 
  hand, 
  

   grows 
  much 
  more 
  readily 
  on 
  the 
  freshly 
  killed 
  chinch-bug 
  tiian 
  on 
  

   the 
  living. 
  Both 
  muscardines 
  were 
  most 
  abundant 
  in 
  th(> 
  fields, 
  with 
  

   the 
  exception 
  of 
  the 
  Mahomet 
  neighborhood, 
  where 
  the 
  adults 
  of 
  the 
  

  

  * 
  Set- 
  here 
  especially 
  the 
  dissections 
  reported 
  unfler 
  Odin. 
  July 
  tJ. 
  

  

  