﻿80 
  REPORT 
  UNITED 
  STATES 
  ENTOMOLOGICAL 
  COMMISSION. 
  

  

  to 
  incorrect 
  conclusions; 
  hence 
  we 
  haAe 
  found 
  it 
  necessary, 
  in 
  dis- 
  

   cussing 
  points 
  relating 
  to 
  migrations, 
  to 
  use 
  some 
  term 
  that 
  would 
  

   distinguish 
  these 
  flights 
  from 
  what 
  may 
  be 
  more 
  properly 
  termed 
  true 
  

   migrations. 
  

  

  Strange 
  as 
  it 
  may 
  appear 
  to 
  those 
  who 
  have 
  not 
  carefully 
  studied 
  the- 
  

   characteristics 
  and 
  habits 
  of 
  our 
  western 
  locust 
  that 
  it 
  should 
  be 
  possi- 
  

   ble 
  to 
  distinguish 
  a 
  local 
  from 
  an 
  invading 
  swarm 
  ; 
  yet, 
  as 
  we 
  have 
  here- 
  

   tofore 
  stated, 
  this 
  may 
  be 
  done 
  in 
  almost 
  every 
  instance, 
  even 
  when 
  

   moving 
  in 
  the 
  same 
  direction, 
  and 
  apparently 
  from 
  the 
  same 
  point. 
  As 
  

   an 
  illustration 
  of 
  the 
  use 
  of 
  the 
  term, 
  we 
  call 
  attention 
  to 
  the 
  records 
  of 
  

   autumn 
  flights 
  of 
  1877 
  in 
  Appendix 
  XII 
  of 
  our 
  former 
  report. 
  These 
  

   were 
  in 
  nearly 
  every 
  instance, 
  where 
  south 
  of 
  Minnesota, 
  from 
  the 
  north- 
  

   west, 
  yet, 
  as 
  was 
  then 
  pretty 
  well 
  known, 
  and 
  as 
  since 
  ascertained, 
  those 
  

   hatched 
  in 
  the 
  temporary 
  regions, 
  most 
  of 
  which 
  having 
  flown 
  north 
  as 
  

   far 
  as 
  Dakota 
  again 
  turned 
  southward, 
  being 
  joined 
  usually 
  by 
  those 
  of 
  

   the 
  section 
  where 
  they 
  again 
  started 
  southward. 
  In 
  some 
  instances 
  our 
  

   data 
  from 
  local 
  observers 
  enabled 
  us 
  to 
  designate 
  the 
  time 
  and 
  section 
  

   when 
  and 
  where 
  this 
  change 
  of 
  course 
  began. 
  

  

  The 
  data 
  obtained 
  for 
  1877 
  — 
  which, 
  as 
  will 
  be 
  seen 
  by 
  reference 
  to 
  our 
  

   former 
  report, 
  are 
  very 
  full 
  — 
  show 
  that 
  there 
  is 
  considerable 
  difference 
  in 
  

   these 
  local 
  flights 
  in 
  the 
  area 
  from 
  Dakota 
  south 
  to 
  Texas 
  and 
  the 
  area 
  

   embracing 
  Minnesota 
  and 
  Northern 
  Iowa, 
  the 
  Coteau 
  des 
  Prairies 
  form- 
  

   ing 
  the 
  dividing 
  line. 
  In 
  the 
  former 
  the 
  flights 
  were 
  uniformly 
  northward 
  

   until 
  in 
  July, 
  after 
  which 
  they 
  were 
  southward 
  until 
  in 
  September, 
  the 
  

   turning 
  point 
  being 
  somewhere 
  in 
  Dakota, 
  after 
  which 
  there 
  was 
  but 
  

   little 
  flying 
  either 
  way, 
  the 
  locusts 
  doubtless 
  perishing 
  after 
  their 
  flight 
  

   southward, 
  and 
  generally 
  without 
  doing 
  injury 
  or 
  depositing 
  any 
  eggs. 
  

   On 
  the 
  other 
  hand, 
  there 
  were, 
  as 
  will 
  be 
  seen 
  by 
  the 
  following 
  extract 
  

   from 
  Mr. 
  Whitman's 
  report, 
  repeated 
  flights 
  to 
  the 
  northwest 
  and 
  south- 
  

   east 
  through 
  Minnesota 
  : 
  

  

  To 
  sum 
  up 
  ; 
  July 
  1 
  the 
  air 
  was 
  thick 
  with 
  locusts 
  over 
  a 
  considerable 
  portion 
  of 
  the 
  

   State. 
  July 
  3 
  to 
  6 
  they 
  moved 
  across 
  the 
  State 
  to 
  the 
  northwest, 
  and 
  turning 
  at 
  Mor- 
  

   ris 
  westward; 
  on 
  July 
  8 
  to 
  10, 
  crossed 
  the 
  State 
  to 
  the 
  southeast;; 
  July 
  11 
  and 
  12, 
  

   crossed 
  the 
  State 
  to 
  the 
  northwest 
  ; 
  July 
  20 
  and 
  21, 
  after 
  the 
  wind 
  had 
  been 
  blowing 
  

   from 
  the 
  northwest 
  for 
  four 
  days, 
  they 
  crossed 
  the 
  State 
  again 
  to 
  the 
  southeast 
  ; 
  July 
  

   28, 
  after 
  some 
  flying 
  to 
  the 
  northwest, 
  crossed 
  the 
  southwestern 
  corner 
  of 
  the 
  State 
  to 
  

   the 
  southeast 
  ; 
  August 
  2, 
  crossed 
  the 
  State 
  to 
  the 
  southeast 
  in 
  full 
  force. 
  To 
  all 
  ap- 
  

   pearance 
  the 
  locusts 
  have 
  spent 
  the 
  greater 
  part 
  of 
  their 
  time 
  in 
  the 
  air 
  since 
  July 
  10. 
  

  

  In 
  1875 
  the 
  local 
  flights 
  were 
  not 
  so 
  marked 
  as 
  in 
  1877 
  ; 
  in 
  that 
  year 
  

   the 
  return 
  flights 
  generally 
  reached 
  their 
  destination 
  — 
  their 
  native 
  

   habitats 
  in 
  the 
  permanent 
  region 
  — 
  but 
  in 
  the 
  latter 
  year, 
  on 
  account 
  of 
  

   adverse 
  winds 
  or 
  their 
  diseased 
  condition, 
  which 
  was 
  very 
  marked, 
  they 
  

   failed 
  to 
  accomplish 
  the 
  apparent 
  object 
  of 
  their 
  return 
  flights, 
  and 
  hence 
  

   became 
  aimless 
  wanderers, 
  driven 
  to 
  and 
  fro, 
  the 
  weaker 
  dropping 
  out 
  

   and 
  dying 
  as 
  they 
  moved 
  until 
  all 
  had 
  disappeared. 
  Our 
  local 
  reports 
  

   are 
  full 
  of 
  accounts 
  of 
  their 
  dropping 
  as 
  swarms 
  moved 
  over. 
  

  

  As 
  heretofore 
  stated, 
  it 
  is 
  true 
  that 
  it 
  is 
  possible 
  in 
  almost 
  every 
  in- 
  

  

  