﻿€24 
  REPORT 
  UNITED 
  STATES 
  GEOLOGICAL 
  SURVEY. 
  

  

  of 
  going 
  northward, 
  as 
  is 
  usual 
  with 
  the 
  spring 
  broods 
  hatched 
  in 
  the 
  Missouri 
  River 
  

   Valley. 
  No 
  northward 
  or 
  return 
  flight 
  was 
  noticed 
  over 
  the 
  Big 
  Horn 
  region 
  during 
  

   the 
  season 
  of 
  1876. 
  

  

  About 
  the 
  last 
  of 
  July, 
  1876, 
  the 
  great 
  flights 
  from 
  the 
  northwest 
  swarmed 
  over 
  the 
  

   country 
  along 
  the 
  eastern 
  base 
  of 
  the 
  Big 
  Horn 
  Mountains. 
  They 
  came 
  in 
  such 
  nuna- 
  

   bers 
  as 
  to 
  create 
  a 
  hazy 
  atmosphere 
  which 
  was 
  at 
  first 
  supposed 
  to 
  be 
  due 
  to 
  prairie 
  

   fires. 
  During 
  severals 
  days 
  they 
  covered 
  the 
  earth 
  and 
  obscured 
  the 
  sun. 
  Their 
  line 
  

   of 
  flight 
  was 
  from 
  the 
  west 
  of 
  north, 
  and 
  in 
  general 
  appeared 
  to 
  conform 
  to 
  the 
  contour 
  

   of 
  the 
  mountain-range, 
  following 
  it 
  to 
  the 
  southward 
  and 
  eastward. 
  For 
  some 
  time 
  

   after 
  reaching 
  the 
  ground 
  they 
  seemed 
  bewildered 
  and 
  inactive, 
  but 
  gradually 
  recovered 
  

   and 
  commenced 
  eating 
  voraciously 
  and 
  pairing 
  off. 
  I 
  did 
  not, 
  however, 
  observe 
  them 
  

   lay 
  eggs 
  here. 
  After 
  remaining 
  about 
  a 
  week 
  they 
  nearly 
  all 
  left 
  one 
  afternoon 
  just 
  as 
  

   a 
  stiff 
  breeze 
  was 
  springing 
  up 
  from 
  the 
  northwest, 
  their 
  flight 
  being 
  still 
  to 
  the 
  south- 
  

   east. 
  Of 
  those 
  which 
  remained 
  behind, 
  about 
  one-fourth 
  appeared 
  disabled 
  for 
  vigor- 
  

   ous 
  flight 
  from 
  the 
  presence 
  of 
  the 
  eggs 
  of 
  the 
  parasitic 
  mites 
  which 
  destroy 
  so 
  many 
  ; 
  

   the 
  little 
  red 
  oblong 
  mite^ 
  which 
  were 
  firmly 
  attached 
  to 
  the 
  under 
  side 
  of 
  the 
  wings, 
  

   impeding 
  them 
  greatly 
  and 
  causing 
  their 
  ultimate 
  destruction. 
  Many 
  other 
  individuals 
  

   had 
  a 
  sickly 
  appearance, 
  though 
  I 
  could 
  discover 
  nothing 
  unusual 
  affecting 
  then 
  except- 
  

   ing 
  a 
  general 
  paleness 
  of 
  the 
  body 
  and 
  wings 
  and 
  extreme 
  weakness. 
  These 
  swarms 
  

   appeared 
  in 
  Western 
  Nebraska 
  about 
  the 
  middle 
  of 
  August. 
  

  

  Upon 
  leaving 
  the 
  Big 
  Horn 
  Mountain 
  I 
  passed 
  in 
  a 
  northeasterly 
  direction 
  over 
  the 
  

   region 
  drained 
  by 
  the 
  Rose 
  Bud, 
  Tongue, 
  Powder, 
  and 
  Yellowstone 
  Rivers, 
  and 
  every- 
  

   where 
  found 
  evidence, 
  in 
  the 
  condition 
  of 
  vegetation 
  and 
  the 
  large 
  quantity 
  of 
  " 
  frass 
  " 
  

   on 
  the 
  ground, 
  that 
  a 
  flight 
  had 
  also 
  been 
  here. 
  I 
  believe 
  this 
  to 
  have 
  been 
  part 
  of 
  

   the 
  great 
  flight 
  observed 
  at 
  the 
  base 
  of 
  the 
  Big 
  Horn 
  Mountains, 
  and 
  it 
  consequently 
  

   must 
  have 
  covered, 
  at 
  the 
  same 
  time, 
  about 
  12,000 
  square 
  miles 
  of 
  territory. 
  

  

  It 
  would 
  appear 
  as 
  though 
  the 
  great 
  swarms, 
  which 
  are 
  so 
  destructive 
  to 
  eastern 
  

   vegetation, 
  follow 
  in 
  their 
  eastward 
  flight 
  the 
  general 
  trend 
  of 
  our 
  western 
  mountains. 
  

   Starting, 
  as 
  we 
  suppose, 
  from 
  the 
  Great 
  Plains 
  at 
  the 
  head 
  of 
  the 
  Saskatchewan 
  River, 
  

   they 
  would 
  follow 
  it 
  down 
  to 
  the 
  spurs 
  of 
  the 
  Rocky 
  Mountain 
  chain, 
  which 
  curve 
  to 
  

   the 
  southeastward 
  and 
  offer 
  a 
  continuous 
  area 
  of 
  vegetation 
  to 
  sustain 
  them 
  in 
  their 
  

   journey. 
  The 
  Big 
  Horn 
  Mountains 
  next 
  come 
  in 
  view, 
  and 
  by 
  their 
  contour 
  tend 
  to 
  

   place 
  tbem 
  well 
  to 
  the 
  south 
  by 
  the 
  time 
  they 
  reach 
  the 
  southern 
  end. 
  

  

  The 
  next 
  objective 
  point 
  in 
  their 
  flight 
  would 
  be 
  the 
  Black 
  Hills, 
  which 
  are 
  densely 
  

   timbered, 
  and 
  would 
  naturally 
  attract 
  them 
  from 
  a 
  distance. 
  After 
  leaving 
  this 
  latter 
  

   region 
  there 
  are 
  no 
  prominent 
  elevations 
  to 
  guide 
  them 
  in 
  their 
  flight, 
  and 
  they 
  con- 
  

   sequently 
  follow 
  the 
  drainage 
  of 
  the 
  Missouri 
  Valley, 
  stopping 
  when 
  the 
  bright 
  green 
  

   fields 
  of 
  our 
  farming 
  communities 
  are 
  reached 
  and 
  suitable 
  food 
  obtained. 
  The 
  short 
  

   prairie 
  grasses 
  at 
  the 
  season 
  of 
  their 
  migratory 
  flight 
  have 
  lost 
  their 
  freshness 
  and 
  

   begun 
  to 
  turn 
  yellow. 
  The 
  prairies 
  are 
  consequently 
  not 
  attractive 
  to 
  them, 
  and 
  they 
  

   only 
  halt 
  briefly 
  for 
  rest. 
  But 
  when 
  the 
  tall, 
  luxuriant 
  vegetation 
  of 
  the 
  east 
  is 
  

   reached, 
  they 
  instinctively 
  realize 
  that 
  they 
  have 
  arrived 
  in 
  a 
  land 
  of 
  plenty, 
  and 
  

   accordingly 
  leave 
  their 
  eggs 
  where 
  their 
  young 
  will 
  find 
  abundance 
  of 
  food 
  upon 
  

   hatching 
  out. 
  

  

  In 
  the 
  southward 
  flight 
  of 
  these 
  great 
  swarms, 
  I 
  believe 
  that 
  they 
  never 
  extend 
  as 
  

   far 
  as 
  Laramie 
  Plains. 
  The 
  valley 
  of 
  the 
  Upper 
  North 
  Platte 
  appears 
  to 
  be 
  the 
  southern 
  

   limit 
  of 
  their 
  migration, 
  although 
  they 
  cross 
  the 
  Platte 
  farther 
  to 
  the 
  eastward 
  and 
  

   overrun 
  Eastern 
  Colorado 
  and 
  Kansas. 
  The 
  Upper 
  North 
  Platte 
  Valley 
  is 
  a 
  region 
  of 
  

   very 
  high 
  winds 
  and 
  perhaps 
  unsuited 
  for 
  this 
  reason 
  as 
  a 
  highway 
  of 
  travel 
  ; 
  while 
  

   the 
  line 
  of 
  flight 
  chosen 
  by 
  them 
  is 
  through 
  a 
  country 
  unusually 
  free 
  from 
  atmospheric 
  

   disturbances. 
  

  

  The 
  grasshoppers 
  which 
  visit 
  that 
  part 
  of 
  Colorado 
  extending 
  for 
  some 
  distance 
  east- 
  

   ward 
  of 
  the 
  mountains, 
  I 
  believe, 
  take 
  their 
  flight 
  from 
  Utah, 
  and 
  travel 
  nearly 
  due 
  

   east 
  over 
  the 
  vast 
  intervening 
  mountain-ranges. 
  The 
  members 
  of 
  Professor 
  Hayden's 
  

   Geological 
  Survey 
  of 
  Colorado 
  observed 
  them 
  in 
  1873, 
  on 
  the 
  summits 
  of 
  all 
  the 
  high- 
  

   est 
  peaks, 
  in 
  vast 
  numbers. 
  I 
  have 
  never 
  heard 
  of 
  a 
  flight 
  crossing 
  the 
  Union 
  Pacific 
  

   Railroad 
  near 
  Cheyenne, 
  Wyo., 
  and 
  moving 
  due 
  south 
  into 
  Colorado 
  along 
  the 
  mount- 
  

   ain-range 
  which 
  here 
  runs 
  north 
  and 
  south. 
  And 
  this 
  would 
  have 
  been 
  observed 
  

   if 
  they 
  entered 
  Northern 
  Colorado 
  from 
  the 
  north 
  instead 
  of 
  from 
  the 
  west. 
  The 
  main 
  

   range 
  of 
  Colorado, 
  from 
  its 
  great 
  altitude, 
  offers 
  a 
  formidable 
  barrier 
  to 
  their 
  eastward 
  

   progress, 
  causing 
  myriads 
  to 
  perish 
  from 
  the 
  cold 
  which 
  pervades 
  these 
  elevated 
  re- 
  

   gions. 
  

  

  If 
  the 
  country 
  between 
  the 
  Big 
  Horn 
  Mountains 
  and 
  the 
  Black 
  Hills 
  and 
  the 
  Upper 
  Mis- 
  

   souri 
  and 
  North 
  Platte 
  Rivers 
  were 
  a 
  thickly-settled 
  farming 
  region, 
  the 
  great 
  swarms 
  

   on 
  their 
  eastward 
  journey 
  would 
  stop 
  here, 
  and 
  never 
  reach 
  the 
  Lower 
  Missouri 
  Valley. 
  

   The 
  westward 
  progress 
  of 
  civilization 
  must 
  ever 
  decrease 
  the 
  amount 
  of 
  damage 
  done 
  

   to 
  eastern 
  agriculture 
  ; 
  and 
  finally 
  when 
  the 
  entire 
  "West 
  shall 
  be 
  settled, 
  the 
  cultivated 
  

   fields 
  will 
  be 
  extended 
  over 
  such 
  a 
  wide 
  area 
  that 
  the 
  swarms 
  will 
  be 
  proportionately 
  

   arrested 
  and 
  scattered, 
  and 
  the* 
  destruction 
  of 
  crops 
  in 
  any 
  particular 
  State 
  be 
  incon- 
  

   siderable. 
  

  

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