﻿30 
  REPORT 
  UNITED 
  STATES 
  ENTOMOLOGICAL 
  COMMISSION. 
  

  

  As 
  would 
  be 
  expected, 
  a 
  country 
  as 
  large 
  as 
  this 
  must 
  necessarily 
  

   vary 
  to 
  some 
  extent 
  in 
  its 
  surface 
  configuration, 
  and 
  in 
  its 
  general 
  ap- 
  

   pearance; 
  but, 
  as 
  a 
  rule, 
  it 
  is 
  composed 
  of 
  wide 
  stretches 
  of 
  prairie 
  in- 
  

   terspersed 
  with 
  a 
  few 
  small 
  timbered 
  areas 
  and 
  snow-capped 
  mountain 
  

   ranges. 
  It 
  is 
  watered 
  by 
  the 
  great 
  water 
  systems 
  of 
  the 
  Missouri, 
  the 
  

   Yellowstone, 
  Platte, 
  Colorado, 
  and 
  Columbia, 
  with 
  many 
  minor 
  rivers, 
  

   along 
  the 
  fertile 
  valleys 
  of 
  which 
  the 
  young 
  locusts 
  are 
  reared 
  from 
  

   year 
  to 
  year 
  in 
  numbers 
  sufficiently 
  great 
  always 
  to 
  keep 
  the 
  stock 
  large 
  

   enough 
  so 
  that 
  with 
  a 
  few 
  favorable 
  years 
  this 
  entire 
  area 
  with 
  the 
  

   adjoining 
  country 
  can 
  be 
  stocked 
  and 
  overrun 
  by 
  ravishing 
  swarms. 
  

  

  While 
  the 
  locust 
  is 
  capable 
  of 
  continuing 
  its 
  existence 
  on 
  any 
  favor- 
  

   able 
  portion 
  of 
  this 
  Permanent 
  Eegion, 
  there 
  are 
  in 
  reality 
  but 
  few 
  por- 
  

   tions 
  of 
  it 
  that, 
  on 
  account 
  of 
  their 
  extent, 
  are 
  adapted 
  to 
  its 
  greatest 
  

   increase. 
  These 
  are 
  far 
  apart, 
  and 
  at 
  times 
  are 
  the 
  cradles 
  of 
  swarms 
  

   that 
  visit 
  different 
  sections 
  of 
  the 
  cultivated 
  districts 
  adjoining 
  them. 
  

   The 
  largest, 
  and 
  by 
  far 
  the 
  most 
  important 
  of 
  these, 
  is 
  that 
  of 
  Central 
  

   Montana 
  and 
  portions 
  of 
  the 
  British 
  Possessions 
  immediately 
  to 
  the 
  

   north. 
  The 
  boundaries 
  of 
  this 
  area 
  can 
  be 
  put 
  down 
  as 
  follows 
  : 
  On 
  

   the 
  east 
  a 
  line 
  beginning 
  near 
  the 
  Black 
  Hills 
  and 
  running 
  north 
  by 
  

   the 
  way 
  of 
  the 
  mouth 
  of 
  the 
  Musselshell 
  Eiver 
  to 
  the 
  Saskatchawan 
  

   River 
  and 
  the 
  northern 
  limit 
  of 
  true 
  prairie. 
  The 
  western 
  boundary 
  

   is 
  almost 
  equivalent 
  to 
  the 
  trend 
  of 
  the 
  Eocky 
  Mountain 
  Eange, 
  coming 
  

   as 
  far 
  south 
  as 
  the 
  Sweetwater 
  Basin 
  of 
  Northern 
  Wyoming. 
  In 
  other 
  

   words 
  it 
  passes 
  from 
  the 
  Big 
  Horn 
  Mountains 
  in 
  Northern 
  Wyoming 
  in 
  

   an 
  almost 
  direct 
  line 
  to 
  Fort 
  Shaw, 
  and 
  thence 
  north 
  as 
  far 
  as 
  the 
  prai- 
  

   ries 
  extend, 
  taking 
  in 
  the 
  valleys 
  of 
  the 
  Gallatins, 
  Jefferson, 
  and 
  Prickly 
  

   Pear 
  Eivers 
  as 
  side 
  shoots. 
  The 
  next 
  in 
  importance 
  and 
  size 
  is 
  that 
  of 
  

   which 
  the 
  Snake 
  Eiver 
  Valley 
  is 
  the 
  center. 
  This 
  district 
  comprises 
  

   all 
  of 
  Central 
  and 
  most 
  of 
  Southern 
  Idaho, 
  portions 
  of 
  Northern 
  Utah 
  

   and 
  a 
  small 
  part 
  of 
  Nevada 
  and 
  Eastern 
  Oregon. 
  A 
  third 
  area 
  is 
  that 
  

   of 
  Southern 
  Utah 
  and 
  portions 
  of 
  Northern 
  Arizona 
  and 
  New 
  Mexico, 
  

   with 
  a 
  part 
  of 
  Colorado. 
  

  

  From 
  the 
  former 
  come 
  all 
  the 
  locust 
  swarms 
  that 
  devastate 
  Manitoba, 
  

   Dakota, 
  Minnesota, 
  and 
  at 
  times 
  Nebraska, 
  Iowa, 
  and 
  Kansas, 
  with 
  a 
  

   small 
  portion 
  of 
  Missouri. 
  Oregon, 
  Nevada, 
  and 
  Washington 
  Territory 
  

   receive 
  most 
  of 
  their 
  locust 
  swarms 
  from 
  the 
  second, 
  while 
  Utah 
  and 
  

   Colorado, 
  with 
  adjoining 
  portions 
  of 
  Wyoming, 
  receive 
  theirs 
  from 
  both 
  

   this 
  and 
  the 
  third 
  or 
  that 
  of 
  Arizona 
  and 
  New 
  Mexico. 
  While 
  these 
  

   are 
  the 
  principal 
  courses 
  taken 
  by 
  swarms 
  in 
  leaving 
  these 
  several 
  

   locust 
  centers, 
  they 
  occasionally 
  interchange 
  swarms 
  and 
  then 
  these 
  

   localities 
  receive 
  calls 
  from 
  all 
  three 
  sections. 
  Montana 
  swarms 
  cross 
  

   over 
  the 
  range 
  into 
  the 
  valley 
  of 
  the 
  Snake 
  Eiver, 
  by 
  way 
  of 
  the 
  Madi- 
  

   son, 
  and 
  into 
  the 
  northern 
  part 
  of 
  Idaho 
  and 
  Washington 
  Territory 
  by 
  

   way 
  of 
  the 
  Boundary 
  Pass 
  and 
  Flathead 
  Lake. 
  Those 
  of 
  the 
  Central 
  

   region 
  pass 
  northeast 
  into 
  Montana, 
  both 
  by 
  the 
  Madison 
  and 
  by 
  way 
  

  

  