﻿590 
  REPORT 
  UNITED 
  STATES 
  GEOLOGICAL 
  SURVEY. 
  

  

  The 
  facts 
  here 
  presented 
  may 
  often 
  seem 
  disconnected 
  and 
  desultory, 
  

   but 
  few 
  except 
  experts 
  in 
  natural 
  history 
  are 
  perhaps 
  aware 
  how 
  diffi- 
  

   cult 
  a 
  task 
  it 
  is 
  to 
  follow 
  out 
  the 
  transformations 
  of 
  any 
  particular 
  in- 
  

   sect, 
  and 
  study 
  thoroughly 
  its 
  habits 
  in 
  its 
  different 
  stages 
  of 
  growth. 
  

   Unlike 
  fishes, 
  birds, 
  and 
  quadrupeds, 
  which 
  have 
  similar 
  habits 
  at 
  all 
  

   stages 
  of 
  growth, 
  an 
  insect, 
  with 
  its 
  three 
  separate 
  stages 
  of 
  larva, 
  pupa, 
  

   and 
  adult, 
  leads, 
  as. 
  it 
  were, 
  three 
  lives, 
  with 
  different 
  surroundings, 
  and 
  

   in 
  each 
  of 
  these 
  stages 
  may 
  be 
  regarded 
  as 
  a 
  different 
  animal. 
  Then 
  it 
  

   is 
  often 
  extremely 
  difficult 
  to 
  ascertain 
  of 
  wliat 
  beetle 
  or 
  moth 
  or 
  bee 
  

   such 
  or 
  such 
  a 
  grub 
  or 
  caterpillar 
  is 
  the 
  young. 
  Oup 
  entomologists 
  are 
  

   not 
  numerous 
  enough, 
  and 
  often, 
  from 
  their 
  time 
  being 
  taken 
  up 
  with 
  the 
  

   pursuit 
  of 
  their 
  profession, 
  usually 
  not 
  that 
  of 
  science, 
  are 
  unable 
  to 
  be 
  

   long 
  enough 
  in 
  the 
  field 
  to 
  observe 
  for 
  themselves 
  the 
  habits 
  of 
  insects. 
  

   Unfortunately, 
  also, 
  so 
  backward 
  is 
  the 
  science 
  of 
  entomology 
  in 
  this 
  

   country, 
  that 
  its 
  students 
  are 
  at 
  present 
  fully 
  engrossed 
  with 
  the 
  labor 
  

   of 
  classifying 
  and 
  describing 
  the 
  adult 
  insects. 
  When 
  it 
  is 
  to 
  be 
  borne 
  

   in 
  mind 
  that 
  there 
  are 
  within 
  the 
  limits 
  of 
  the 
  United 
  States, 
  probably 
  

   at 
  a 
  low 
  estimate, 
  10,000 
  species 
  of 
  Hyinenoptera 
  (bees, 
  wasps, 
  ichueu- 
  

   mon-flies, 
  saw-flies, 
  etc.), 
  nearly 
  as 
  many 
  butterflies 
  and 
  moths, 
  about 
  

   10,000 
  species 
  of 
  two-winged 
  flies 
  {Diptera), 
  as 
  many 
  beetles 
  {Coleoptera) 
  

   and 
  bugs 
  [Hemi-ptera)^ 
  and 
  several 
  thousand 
  species 
  of 
  grasshoppers, 
  

   etc. 
  (Orthoptera), 
  and 
  neuropterous 
  insects, 
  such 
  as 
  dragon-flies, 
  cad- 
  

   dis-flies, 
  etc., 
  etc., 
  the 
  whole 
  amounting 
  to 
  upward 
  of 
  50,000 
  species 
  of 
  

   insects, 
  not 
  to 
  speak 
  of 
  the 
  spiders, 
  mites, 
  and 
  ticks, 
  centipedes 
  and 
  

   millipedes, 
  it 
  is 
  evident 
  that 
  in 
  the 
  mere 
  preliminary 
  work 
  of 
  identify- 
  

   ing 
  and 
  properly 
  describing 
  these 
  myriad 
  forms 
  — 
  an 
  intellectual 
  work 
  

   requiring 
  quite 
  as 
  much 
  good 
  sense, 
  discretion, 
  and 
  knowledge 
  as 
  is 
  

   shown 
  in 
  the 
  f>ursuit 
  of 
  medicine, 
  the 
  law, 
  or 
  teaching 
  — 
  it 
  is 
  evident 
  

   that 
  all 
  this 
  work, 
  which 
  is 
  simply 
  preliminary 
  in 
  its 
  nature, 
  is 
  ^a 
  vast 
  

   oue, 
  and 
  that 
  the 
  combined 
  exertions 
  of 
  many 
  minds 
  over 
  several 
  gen- 
  

   erations 
  will 
  not 
  exhaust 
  the 
  subject. 
  As 
  it 
  is, 
  there 
  are 
  in 
  this 
  country 
  

   only 
  about 
  thirty 
  entomologists 
  who 
  publish 
  anything 
  relating 
  to 
  in- 
  

   sects. 
  Necessary 
  as 
  it 
  is, 
  this 
  work 
  of 
  classification 
  is 
  by 
  no 
  means 
  the 
  

   highest 
  and 
  most 
  useful 
  branch 
  of 
  natural 
  science. 
  He 
  who 
  studies 
  

   carefully 
  the 
  habits 
  and 
  structure 
  of 
  one 
  insect, 
  and, 
  if 
  it 
  is 
  iojurious 
  to 
  

   agriculture, 
  lays 
  before 
  the 
  farmer 
  or 
  gardener 
  a 
  true 
  story 
  of 
  its 
  life, 
  is 
  

   a 
  true 
  benefactor 
  to 
  agriculture, 
  and 
  at 
  the 
  same 
  time 
  benefits 
  science 
  

   more 
  than 
  he 
  who 
  describes 
  hundreds 
  of 
  new 
  species. 
  

  

  We 
  have 
  little 
  idea 
  how 
  many 
  kinds 
  of 
  insects 
  are 
  preying 
  upon 
  our 
  

   field 
  and 
  garden 
  crops, 
  our 
  shade, 
  ornamental, 
  and 
  forest 
  trees. 
  There 
  

   are, 
  probably, 
  within 
  the 
  limits 
  of 
  our 
  country 
  5,000 
  different 
  kinds, 
  

   which 
  are 
  either 
  at 
  present 
  engaged 
  in 
  the 
  work 
  of 
  devastation, 
  or 
  are 
  

   destined 
  to 
  be, 
  with 
  the 
  growth 
  of 
  civilization, 
  which 
  means 
  in 
  this 
  in- 
  

   stance 
  the 
  destruction 
  of 
  the 
  natural 
  food 
  of 
  these 
  insects 
  and 
  the 
  sub- 
  

   stitution 
  of 
  a 
  similar 
  diet, 
  our 
  choicest 
  grains 
  and 
  fruits, 
  in 
  its 
  stead. 
  

  

  In 
  the 
  densely-populated 
  countries 
  of 
  Europe 
  the 
  losses 
  occasioned 
  

   by 
  injurious 
  insects 
  are 
  most 
  severely 
  felt, 
  though 
  from 
  many 
  causes, 
  such 
  

   as 
  the 
  greater 
  abundance 
  of 
  their 
  insect-parasites 
  and 
  the 
  far 
  greater 
  

   care 
  tal^en 
  by 
  the 
  people 
  to 
  exterminate 
  their 
  insect-enemies, 
  they 
  have 
  

   not 
  proved 
  so 
  destructive 
  as 
  in 
  our 
  own 
  land. 
  MM. 
  Pasteur 
  and 
  Qua- 
  

   trefages, 
  whose 
  names 
  are 
  illustrious 
  as 
  original 
  investigators, 
  were 
  com- 
  

   missioned 
  by 
  the 
  French 
  government 
  to 
  study 
  the 
  causes 
  of 
  the 
  silk- 
  

   worm 
  disease, 
  jje&rine, 
  and, 
  as 
  the 
  result 
  of 
  their 
  studies, 
  silk-culture, 
  an 
  

   interest 
  involving 
  millions 
  of 
  dollars, 
  will 
  probably 
  again 
  be 
  restored 
  to 
  

   France 
  and 
  Italy. 
  It 
  should 
  be 
  remembered 
  that 
  this 
  remarkable 
  result 
  is 
  

   due, 
  primarily, 
  to 
  the 
  most 
  abstruse 
  researches 
  upon 
  a 
  microscopic 
  plant 
  

  

  