﻿RETURNING 
  SWARMS 
  DO 
  LITTLE 
  INJURY. 
  81 
  

  

  stance 
  to 
  distinguish 
  an 
  invading 
  from 
  a 
  local 
  swarm, 
  although 
  moving 
  

   in 
  the 
  same 
  direction 
  and 
  apparently 
  from 
  the 
  same 
  point. 
  Those 
  who 
  

   have 
  had 
  considerable 
  experience 
  with 
  them 
  are 
  generally 
  able, 
  from 
  an 
  

   inspection 
  of 
  the 
  insects 
  alone, 
  to 
  decide 
  with 
  reasonable 
  certainty 
  this 
  

   point. 
  But 
  there 
  are 
  other 
  and 
  still 
  more 
  important 
  methods 
  of 
  deter- 
  

   mining 
  it. 
  

  

  It 
  may 
  appear 
  of 
  but 
  little 
  importance 
  to 
  the 
  formers 
  and 
  agricultur- 
  

   ists 
  of 
  Kansas 
  or 
  Nebraska, 
  on 
  whose 
  fields 
  a 
  swarm 
  of 
  locusts 
  has 
  fallen, 
  

   whether 
  they 
  are 
  from 
  the 
  plains 
  of 
  Montana 
  or 
  from 
  the 
  prairies 
  of 
  an 
  

   adjoining 
  State 
  ; 
  but 
  if 
  a 
  careful 
  study 
  of 
  their 
  habits 
  shows 
  it 
  to 
  be 
  a 
  

   general 
  rule 
  that 
  the 
  invading 
  swarms 
  are 
  always, 
  or 
  nearly 
  always, 
  

   destructive 
  in 
  their 
  operations, 
  and 
  that 
  the 
  local 
  swarms 
  are 
  seldom 
  

   injurious, 
  then 
  this 
  knowledge 
  is 
  important. 
  

  

  One 
  object 
  of 
  the 
  Commission 
  has 
  been 
  to 
  study 
  carefully 
  this 
  point, 
  

   for 
  the 
  purpose 
  of 
  ascertaining 
  whether 
  there 
  is 
  any 
  difference 
  in 
  this 
  

   respect 
  between 
  the 
  invading 
  swarms 
  and 
  those 
  which 
  are 
  local 
  or 
  re- 
  

   turning 
  swarms 
  ; 
  not 
  only 
  on 
  account 
  of 
  its 
  direct 
  importance 
  to 
  the 
  

   agriculturists 
  of 
  the 
  invaded 
  States, 
  but 
  also 
  on 
  account 
  of 
  its 
  bearing 
  

   upon 
  the 
  question 
  of 
  their 
  continued 
  vitality 
  in 
  these 
  States. 
  

  

  Early 
  in 
  the 
  season, 
  when 
  rumors 
  of 
  flying 
  locusts 
  came 
  from 
  the 
  

   South, 
  the 
  commissioners 
  in 
  the 
  field 
  were 
  asked 
  to 
  express 
  an 
  opinion 
  

   as 
  to 
  the 
  result 
  ; 
  each, 
  when 
  asked, 
  expressed 
  his 
  opinion 
  without 
  hesi- 
  

   tation, 
  and 
  allowed 
  it 
  to 
  be 
  published 
  far 
  and 
  wide 
  : 
  

  

  We 
  do 
  not 
  apprehend 
  any 
  danger 
  from 
  them. 
  In 
  fact, 
  this 
  is 
  precisely 
  what 
  the 
  

   Commission 
  anticipated, 
  and 
  is 
  one 
  of 
  the 
  strongest 
  possible 
  corroborations 
  of 
  the 
  

   theory 
  held, 
  that 
  these 
  insects 
  can 
  never 
  become 
  permanent 
  residents 
  of 
  this 
  part 
  of 
  the 
  

   Mississippi 
  Valley. 
  

  

  The 
  result 
  confirmed 
  to 
  the 
  fullest 
  extent 
  this 
  opinion, 
  and 
  our 
  pre- 
  

   dictions 
  were 
  fulfilled 
  in 
  a 
  most 
  remarkable 
  manner. 
  Although 
  from 
  

   the 
  middle 
  of 
  June 
  to 
  the 
  last 
  of 
  August 
  of 
  that 
  year 
  swarms 
  were 
  con- 
  

   stantly 
  moving 
  over 
  Minnesota, 
  Dakota, 
  Iowa, 
  Nebraska, 
  and 
  Kansas, 
  

   some 
  days 
  covering 
  an 
  area 
  equal 
  to 
  any 
  two 
  of 
  these 
  States, 
  yet 
  in 
  all 
  

   that 
  time, 
  though 
  visited 
  by 
  myriads 
  after 
  myriads, 
  scarcely 
  a 
  dozen 
  

   fields 
  in 
  all 
  these 
  States 
  were 
  reported 
  as 
  injured. 
  It 
  may 
  therefore 
  be 
  

   stated 
  as 
  a 
  general 
  rule 
  that 
  returning 
  and 
  local 
  swarms 
  do 
  but 
  little 
  

   injury. 
  It 
  is 
  possible 
  that 
  with 
  a 
  different 
  season 
  the 
  result 
  may 
  be 
  

   different, 
  but, 
  so 
  far 
  as 
  the 
  facts 
  heretofore 
  ascertained 
  are 
  concerned, 
  

   they 
  point 
  to 
  the 
  same 
  conclusion 
  5 
  therefore, 
  with 
  the 
  experience 
  of 
  the 
  

   past 
  season 
  adde£* 
  we 
  are 
  justified 
  in 
  giving 
  this 
  as 
  one 
  general 
  rule 
  in 
  

   reference 
  to 
  their 
  habits. 
  

  

  From 
  the 
  facts 
  we 
  have 
  obtained 
  it 
  is 
  evident 
  that 
  there 
  is 
  a 
  marked 
  

   difference 
  between 
  local 
  flights 
  in 
  the 
  permanent 
  and 
  temporary 
  regions. 
  

   In 
  the 
  latter, 
  as 
  just 
  stated, 
  the 
  swarms 
  appear 
  to 
  have 
  little 
  disposition 
  

   to 
  injure 
  vegetation 
  or 
  to 
  deposit 
  eggs, 
  the 
  presumable 
  reasons 
  for 
  which 
  

   are 
  given 
  in 
  our 
  former 
  report. 
  While 
  in 
  the 
  permanent 
  area, 
  apparen 
  tly 
  

  

  ^ 
  at 
  

  

  