﻿AND 
  1676 
  CONTRASTED. 
  7 
  i 
  

  

  Some 
  sections 
  of 
  Minnesota, 
  Dakota, 
  and 
  Northern 
  Iowa 
  were 
  vis 
  

   in 
  this 
  year, 
  but 
  it 
  is 
  impossible 
  to 
  ascertain 
  now 
  whether 
  these 
  were 
  

   "invaders" 
  or 
  not. 
  It 
  is 
  known 
  that 
  in 
  some 
  cases 
  they 
  were 
  from 
  the 
  

   south. 
  

  

  1870. 
  — 
  It 
  is 
  only 
  necessary 
  to 
  refer 
  to 
  our 
  former 
  report 
  to 
  Bee 
  that 
  

   this 
  year 
  was 
  one 
  of 
  general 
  invasion 
  from 
  the 
  northwest 
  reaching 
  from 
  

   Dakota 
  to 
  Texas. 
  

  

  Now 
  let 
  us 
  refer 
  to 
  the 
  locust 
  movements 
  during 
  these 
  years 
  in 
  the 
  

   permanent 
  region. 
  

  

  In 
  1875 
  the 
  locusts 
  visiting 
  Fort 
  Benton 
  and 
  Eastern 
  Montana 
  were 
  

   from 
  the 
  east 
  and 
  southeast 
  ; 
  while 
  those 
  which 
  appeared 
  in 
  1876 
  came 
  

   from 
  the 
  northwest 
  in 
  immense 
  swarms. 
  

  

  In 
  Wyoming 
  vast 
  numbers 
  were 
  observed 
  at 
  Laramie 
  City 
  in 
  1875. 
  

   flying 
  south 
  and 
  southeast. 
  In 
  August 
  of 
  1876 
  swarms 
  were 
  observed 
  

   in 
  Southeast 
  Wyoming, 
  east 
  of 
  the 
  Big 
  Horn 
  Mountains 
  and 
  north 
  of 
  

   Black 
  Hills, 
  flying 
  southeast. 
  In 
  Colorado 
  the 
  flights 
  of 
  1875 
  were 
  from 
  

   the 
  north 
  and 
  northwest, 
  over 
  Greeley 
  and 
  Denver. 
  

  

  In 
  1875, 
  as 
  stated 
  by 
  Professor 
  Dawson 
  — 
  

  

  Foreign 
  swarms 
  from 
  the 
  south 
  crossed 
  the 
  49th 
  parallel 
  with 
  a 
  wide 
  front 
  stretch- 
  

   ing 
  from 
  the 
  98th 
  to 
  the 
  106th 
  meridian, 
  and 
  are 
  quite 
  distinguishable 
  from 
  those 
  pro- 
  

   duced 
  in 
  the 
  country 
  (British 
  Columbia), 
  from 
  the 
  fact 
  that 
  many 
  of 
  them 
  arrived 
  

   before 
  the 
  latter 
  were 
  mature. 
  These 
  flights 
  constituted 
  the 
  extreme 
  northern 
  part 
  

   of 
  the 
  army 
  returning 
  northward 
  and 
  northwestward 
  from 
  the 
  States 
  ravaged 
  in 
  the 
  

   autumn 
  of 
  1874. 
  

  

  From 
  the 
  same 
  authority 
  we 
  learn 
  that 
  the 
  locusts 
  hatched 
  north 
  of 
  

   the 
  boundary 
  line 
  in 
  1876 
  flew 
  southward 
  into 
  the 
  United 
  States. 
  

  

  These 
  facts 
  are 
  sufficient 
  to 
  show 
  that 
  the 
  invading 
  swarms 
  which 
  

   visit 
  the 
  temporary 
  regions 
  south 
  of 
  Dakota 
  come, 
  as 
  a 
  general 
  and 
  al- 
  

   most 
  universal 
  rule, 
  from 
  the 
  permanent 
  area 
  lying 
  to 
  the 
  northwest 
  ;. 
  

   and 
  that 
  the 
  resulting 
  brood 
  of 
  the 
  following 
  year 
  return 
  over 
  the 
  same 
  

   course 
  to 
  the 
  northwest. 
  

  

  The 
  movements 
  in 
  Wyoming 
  and 
  Colorado 
  appear 
  to 
  be 
  independent; 
  

   coming 
  out 
  of 
  the 
  mountains, 
  they 
  move 
  down 
  the 
  east 
  flank 
  into 
  Colo- 
  

   rado, 
  sometimes 
  stopping 
  and 
  producing 
  a 
  brood 
  which 
  next 
  year 
  either 
  

   returns 
  northwestward 
  over 
  the 
  mountains, 
  or 
  as 
  is 
  sometimes 
  the 
  case 
  

   moves 
  farther 
  southward, 
  some 
  passing 
  southwest 
  into 
  South 
  Park 
  and 
  

   adjoining 
  regions, 
  and 
  at 
  other 
  times 
  passing 
  southeast 
  into 
  Texas- 
  

   This 
  will 
  account 
  for 
  the 
  appearance 
  in 
  Texas 
  of 
  invading 
  swarms 
  when 
  

   in 
  the 
  sections 
  north, 
  as 
  in 
  1875, 
  there 
  were 
  no 
  invading 
  swarms. 
  

  

  It 
  appears 
  that 
  returning 
  swarms 
  moving 
  north 
  from 
  Kansas 
  and 
  

   Nebraska 
  through 
  Dakota 
  often 
  turn 
  westward 
  near 
  the 
  middle 
  of 
  the 
  

   Territory, 
  following 
  up 
  the 
  course 
  of 
  the 
  Missouri. 
  

  

  Those 
  invading 
  Manitoba 
  come 
  from 
  the 
  west 
  generally, 
  sometimes 
  

   from 
  the 
  northwest, 
  but 
  occasionally 
  from 
  the 
  direction 
  of 
  Eastern 
  Mon- 
  

   tana. 
  Those 
  invading 
  Minnesota, 
  from 
  the 
  west 
  and 
  northwest. 
  

  

  In 
  the 
  western 
  States 
  these 
  invading 
  swarms 
  are 
  very 
  commonly 
  desig- 
  

  

  