﻿300 
  REPORT 
  UNITED 
  STATES 
  ENTOMOLOGICAL 
  COMMISSION. 
  

  

  with, 
  stunted 
  sage, 
  or 
  are 
  barren. 
  It 
  is 
  unnecessary 
  to 
  go 
  into 
  details 
  

   regarding 
  them, 
  as 
  the 
  accompanying 
  map 
  expresses 
  them 
  better 
  than 
  

   any 
  description 
  could 
  do 
  it. 
  

  

  There 
  is 
  a 
  plainly 
  marked 
  gradation 
  southward 
  in 
  the 
  vegetation. 
  

  

  Of 
  the 
  Mojave 
  Desert, 
  of 
  Southeastern 
  California, 
  little 
  need 
  be 
  said, 
  

   save 
  that 
  it 
  is 
  almost 
  without 
  vegetation, 
  excepting 
  at 
  a 
  few 
  isolated 
  

   spots, 
  where 
  springs 
  break 
  through 
  to 
  the 
  surface, 
  forming 
  small 
  oases, 
  

   and 
  the 
  narrow 
  belt 
  along 
  the 
  Mojave 
  Eiver. 
  On 
  the 
  borders 
  of 
  the 
  

   San 
  Bernardino 
  Range, 
  however, 
  there 
  is 
  a 
  narrow 
  belt 
  of 
  grass, 
  while 
  

   the 
  higher 
  portion 
  of 
  the 
  range 
  is 
  well 
  timbered. 
  

  

  PREVENTIVE 
  MEASURES 
  IN 
  THE 
  PLAINS 
  AREA. 
  

  

  From 
  the 
  foregoing 
  account 
  of 
  the 
  topographical 
  and 
  botanical 
  char- 
  

   acteristics 
  of 
  the 
  different 
  areas 
  in 
  the 
  Permanent 
  Eegion, 
  taken 
  in 
  con- 
  

   nection 
  with 
  what 
  we 
  have 
  said 
  both 
  in 
  this 
  and 
  our 
  previous 
  report, 
  it 
  

   is 
  obvious 
  that 
  the 
  plains 
  area 
  transcends 
  in 
  importance 
  all 
  the 
  other 
  

   areas 
  here 
  considered, 
  from 
  the 
  locust 
  point 
  of 
  view. 
  

  

  The 
  surface 
  conditions 
  under 
  which 
  Caloptenus 
  sjpretus 
  breeds 
  in 
  the 
  

   greatest 
  abundance 
  are 
  a 
  loose, 
  warm, 
  gravelly 
  soil 
  covered 
  by 
  a 
  tolerably 
  

   luxuriant 
  growth 
  of 
  grasses, 
  such 
  as 
  are 
  found 
  in 
  most 
  river 
  bottoms 
  ; 
  

   in 
  the 
  northern 
  part 
  of 
  the 
  plains 
  of 
  British 
  America, 
  along 
  the 
  bases 
  of 
  

   the 
  mountain 
  ranges, 
  and 
  in 
  the 
  high 
  mountain 
  valleys. 
  Such 
  areas 
  are 
  

   of 
  greater 
  extent 
  in 
  the 
  northern 
  portion 
  of 
  the 
  region 
  which 
  we 
  have 
  

   described, 
  becoming 
  very 
  much 
  more 
  limited 
  in 
  the 
  Southern 
  States 
  and 
  

   Territories. 
  

  

  While 
  it 
  is 
  quite 
  possible 
  that 
  the 
  insects 
  may 
  breed 
  anywhere 
  on 
  the 
  

   plains, 
  it 
  is 
  certain 
  that, 
  as 
  shown 
  in 
  our 
  first 
  report, 
  the 
  more 
  fertile 
  

   portions 
  of 
  this 
  area, 
  and 
  especially 
  that 
  great 
  fertile 
  belt 
  between 
  the 
  

   two 
  Saskatchewans, 
  in 
  British 
  America, 
  is 
  the 
  principal 
  source 
  of 
  the 
  

   swarms 
  which 
  at 
  times 
  sweep 
  down 
  upon 
  the 
  prairies. 
  The 
  extent 
  of 
  

   these 
  breeding 
  grounds 
  in 
  British 
  America 
  may 
  be 
  approximately 
  esti- 
  

   mated 
  at 
  about 
  100,000 
  square 
  miles. 
  

  

  In 
  Montana 
  there 
  is 
  a 
  broad 
  belt 
  at 
  the 
  eastern 
  base 
  of 
  the 
  Missouri 
  

   Range, 
  extending 
  down 
  the 
  branches 
  of 
  the 
  Missouri 
  River 
  for 
  long 
  

   distances. 
  The 
  country 
  about 
  Sun 
  and 
  Teton 
  Rivers 
  is 
  very 
  luxuriant, 
  

   even 
  as 
  far 
  as 
  their 
  mouths. 
  The 
  Gallatin 
  Valley 
  is 
  luxuriantly 
  grassed. 
  

   The 
  lower 
  slopes 
  of 
  the 
  Judith 
  and 
  other 
  neighboring 
  groups 
  of 
  mount- 
  

   ains, 
  the 
  country 
  about 
  the 
  base 
  of 
  the 
  Yellowstone 
  Range, 
  the 
  valleys 
  

   of 
  the 
  Jefferson 
  and 
  its 
  branches, 
  with 
  the 
  hills 
  in 
  their 
  neighborhood, 
  

   may 
  also 
  be 
  looked 
  upon 
  as 
  breeding 
  places 
  of 
  the 
  pest. 
  On 
  the 
  west- 
  

   ern 
  or 
  Pacific 
  Slope, 
  the 
  valleys 
  of 
  the 
  Deer 
  Lodge, 
  Bitterroot, 
  and 
  Hell- 
  

   gate, 
  and 
  of 
  several 
  of 
  their 
  branches, 
  fall 
  into 
  the 
  same 
  category, 
  as 
  

   also 
  the 
  valleys 
  of 
  the 
  Kootenai, 
  and 
  of 
  Flathead 
  Lake. 
  

  

  The 
  bottom 
  lands 
  of 
  many 
  of 
  the 
  streams 
  of 
  the 
  plains, 
  though 
  com- 
  

   paratively 
  narrow, 
  afford 
  probable 
  breeding 
  grounds. 
  Those 
  of 
  the 
  

   Missouri 
  are 
  quite 
  narrow, 
  but 
  on 
  the 
  Yellowstone 
  they 
  have 
  an 
  average 
  

  

  