﻿REPORT 
  OF 
  THE 
  STATE 
  ENTOMOLOGIST 
  34I 
  

  

  back. 
  Watch 
  the 
  gradual 
  but 
  rapid 
  expansion 
  of 
  the 
  wings, 
  as 
  they 
  

   grow 
  before 
  your 
  eyes 
  — 
  the 
  two 
  membranes 
  of 
  which 
  they 
  are 
  com- 
  

   posed 
  steadily 
  distending 
  as 
  the 
  circulation 
  from 
  the 
  body 
  is 
  forced 
  into 
  

   the 
  veins 
  that 
  lie 
  between. 
  The 
  innumerable 
  wrinkles 
  of 
  the 
  mem- 
  

   branes 
  are 
  smoothed 
  out 
  ; 
  the 
  scales 
  that 
  are 
  implanted 
  in 
  them 
  also 
  in- 
  

   crease 
  in 
  size, 
  until 
  within 
  perhaps 
  half 
  an 
  hour 
  the 
  wings 
  have 
  assumed 
  

   their 
  full 
  development, 
  and 
  display 
  their 
  perfect 
  ornamentation, 
  in 
  pat- 
  

   terns 
  resulting 
  from 
  the 
  combination 
  of 
  nearly 
  half 
  a 
  million 
  of 
  individ- 
  

   ual 
  scales 
  — 
  the 
  most 
  delicate 
  imbrication 
  that 
  may 
  be 
  found 
  in 
  nature, 
  

   and 
  far 
  surpassing 
  any 
  thing 
  that 
  art 
  can 
  produce. 
  

  

  If 
  not 
  deterred 
  by 
  my 
  long 
  recital 
  you 
  will 
  undertake 
  what 
  I 
  have 
  

   proposed 
  — 
  to 
  follow 
  out 
  the 
  life-history 
  of 
  one 
  of 
  our 
  silk-worms, 
  and 
  

   having 
  done 
  so, 
  if 
  you 
  do 
  not 
  find 
  that 
  the 
  study 
  has 
  been 
  one 
  of 
  surpass- 
  

   ing 
  interest, 
  leading 
  you 
  to 
  further 
  study 
  of 
  the 
  kind, 
  and 
  wedding 
  you 
  

   to 
  entomology 
  — 
  then 
  you 
  have 
  been 
  given 
  or 
  have 
  acquired 
  a 
  nature 
  

   that 
  I 
  can 
  not 
  comprehend. 
  

  

  IV. 
  The 
  Practical 
  Importance 
  of 
  the 
  Study. 
  

  

  It 
  is 
  universally 
  conceded 
  that 
  Agricultural 
  pursuits 
  form 
  the 
  basis 
  of 
  

   National 
  prosperity, 
  and 
  that 
  upon 
  the 
  products 
  of 
  the 
  soil 
  our 
  existence 
  

   is 
  dependant. 
  

  

  The 
  existence 
  of 
  the 
  insect 
  world 
  also 
  depends 
  upon 
  vegetable 
  life 
  : 
  

   hence 
  arises 
  that 
  constant 
  antagonism 
  of 
  man 
  to 
  the 
  insect 
  world, 
  which 
  

   becomes 
  so 
  intensified 
  when 
  through 
  his 
  agency 
  as 
  a 
  cultivator 
  of 
  the 
  

   soil, 
  there 
  results 
  excessive 
  multiplication 
  of 
  injurious 
  species 
  preying 
  

   upon 
  crops 
  which 
  he 
  deems 
  essential 
  to 
  him. 
  

  

  Every 
  crop 
  grown 
  is 
  exposed 
  to 
  their 
  attack. 
  It 
  has 
  been 
  estimated 
  

   that 
  there 
  are 
  upon 
  an 
  average, 
  six 
  species 
  of 
  attacking 
  insects 
  to 
  each 
  

   knoAvn 
  plant. 
  From 
  their 
  minute 
  size 
  and 
  the 
  secrecy 
  of 
  their 
  depreda- 
  

   tions, 
  we 
  can 
  not 
  fence 
  them 
  out, 
  as 
  we 
  do 
  our 
  large 
  domestic 
  animals. 
  

   Probably 
  there 
  is 
  no 
  cultivated 
  crop 
  which 
  is 
  not 
  lessened 
  by 
  one-tenth 
  

   through 
  insect 
  injury. 
  Often 
  there 
  is 
  a 
  diminution 
  in 
  yield 
  of 
  one 
  fourth; 
  

   frequently 
  of 
  one-half, 
  and 
  at 
  times 
  there 
  is 
  a 
  total 
  loss, 
  as 
  when 
  during 
  

   the 
  prevalence 
  of 
  the 
  wheat-midge, 
  forty 
  years 
  ago, 
  entire 
  fields 
  of 
  wheat 
  

   were 
  left 
  uncut 
  in 
  New 
  York 
  and 
  other 
  of 
  the 
  wheat 
  states, 
  and 
  for 
  a 
  

   term 
  of 
  years 
  wheat 
  could 
  not 
  be 
  grown. 
  In 
  one 
  year, 
  in 
  our 
  State 
  

   (1854), 
  the 
  loss 
  from 
  this 
  tiny 
  insect 
  was 
  calculated 
  at 
  fifteen 
  millions 
  of 
  

   dollars. 
  Illinois 
  suffered 
  in 
  a 
  single 
  year, 
  in 
  its 
  wheat 
  and 
  corn 
  crops, 
  to 
  

   the 
  amount 
  of 
  seventy-three 
  millions 
  of 
  dollars, 
  according 
  to 
  estimate, 
  

   from 
  the 
  ravages 
  of 
  the 
  chinch-bug 
  {Blissus 
  leucopterus). 
  True, 
  these 
  

   were 
  exceptional 
  years, 
  but 
  from 
  another 
  insect 
  pest, 
  the 
  cotton-worm 
  

  

  