﻿168 
  REPORT 
  UNITED 
  STATES 
  ENTOMOLOGICAL 
  COMMISSION. 
  

  

  coal-oil, 
  or 
  any 
  oily 
  or 
  greasy 
  matter, 
  is 
  sure 
  death, 
  provided 
  the 
  oily 
  

   substance 
  comes 
  in 
  contact 
  with 
  the 
  body 
  or 
  any 
  part 
  of 
  it. 
  As 
  quickly 
  

   as 
  the 
  oil 
  touches 
  the 
  insect 
  it 
  spreads 
  rapidly 
  over 
  the 
  skin, 
  covering 
  the 
  

   spiracles 
  or 
  air-holes 
  with 
  a 
  thin 
  film. 
  

  

  As 
  fields 
  of 
  young 
  grain 
  and 
  corn 
  are 
  sometimes 
  attacked 
  by 
  the 
  

   crickets, 
  one 
  of 
  the 
  best 
  means 
  of 
  getting 
  rid 
  of 
  them 
  adopted 
  in 
  Utah 
  

   is 
  to 
  drive 
  a 
  flock 
  of 
  sheep 
  into 
  the 
  grain- 
  field, 
  keeping 
  them 
  compactly 
  

   herded. 
  By 
  so 
  doing 
  the 
  grain 
  is 
  not 
  materially 
  damaged, 
  we 
  are 
  told, 
  

   and 
  great 
  numbers 
  of 
  the 
  crickets 
  are 
  stamped 
  to 
  death. 
  

  

  It 
  is 
  obvious 
  that 
  most 
  of 
  the 
  means 
  used 
  in 
  fighting 
  the 
  young 
  of 
  

   the 
  Eocky 
  Mountain 
  locust, 
  and 
  already 
  described 
  at 
  length 
  in 
  the 
  First 
  

   Eeport 
  of 
  the 
  Commission, 
  may 
  be 
  applied 
  to 
  the 
  cricket. 
  

  

  Geographical 
  distribution 
  of 
  the 
  species 
  of 
  Andbrus. 
  — 
  The 
  species 
  of 
  this 
  

   genus 
  are 
  characteristic 
  of 
  the 
  central 
  province 
  of 
  the 
  United 
  States, 
  as 
  

   none 
  are 
  found 
  east 
  of 
  longitude 
  95°, 
  and 
  none 
  on 
  the 
  Pacific 
  slope 
  of 
  the 
  

   Cascade 
  Mountains 
  and 
  the 
  Sierra 
  Nevadas. 
  In 
  fact, 
  the 
  geographical 
  

   limits 
  of 
  the 
  Western 
  cricket 
  are 
  probably 
  nearly 
  or 
  quite 
  co-extensive 
  

   with 
  those 
  of 
  the 
  Eocky 
  Mountain 
  locust. 
  210 
  The 
  northern 
  and 
  southern 
  

   limits 
  have 
  not 
  been 
  ascertained. 
  The 
  species 
  are 
  known, 
  however, 
  to 
  

   extend 
  northward 
  as 
  far 
  as 
  Manitoba, 
  and 
  southward 
  into 
  Northern 
  

   New 
  Mexico 
  and 
  into 
  Arizona, 
  but 
  these 
  limits 
  are 
  very 
  indefinitely 
  

   known. 
  

  

  Within 
  the 
  limits 
  of 
  the 
  central 
  zoo-geographical 
  province 
  there 
  are 
  

   two 
  distinct 
  regions 
  tenanted 
  by 
  different 
  species 
  of 
  Anabrus, 
  the 
  line 
  of 
  

   division 
  being 
  the 
  great 
  continental 
  divide, 
  i. 
  e., 
  the 
  highest 
  range 
  of 
  the 
  

   Eocky 
  Mountains. 
  The 
  great 
  basin, 
  with 
  adjoining 
  regions, 
  extending 
  

   from 
  the 
  Columbia 
  Eiver 
  on 
  the 
  north 
  to 
  Nevada 
  and 
  Central 
  — 
  and 
  

   probably 
  Southern 
  — 
  Utah 
  and 
  Arizona 
  on 
  the 
  south, 
  is 
  tenanted 
  by 
  

   Anabrus 
  simplex; 
  while 
  the 
  eastern 
  flank 
  of 
  the 
  Eocky 
  Mountain 
  range, 
  

   with 
  the 
  great 
  plains 
  eastward 
  to 
  about 
  longitude 
  97°, 
  extending 
  from 
  

   Manitoba 
  on 
  the 
  north 
  to 
  Northwestern 
  Texas 
  on 
  the 
  south, 
  is 
  the 
  home 
  

   of 
  Anabrus 
  purpurascens 
  and 
  its 
  ally, 
  Anabrus 
  coloradus. 
  

  

  Mr. 
  Thomas 
  has 
  noticed 
  during 
  his 
  journeys 
  into 
  Utah, 
  Idaho, 
  

   Montana, 
  and 
  Colorado, 
  that 
  whenever 
  he 
  passed 
  to 
  the 
  east 
  side 
  

   of 
  the 
  Eocky 
  Mountain 
  divide, 
  no 
  matter 
  at 
  what 
  point 
  of 
  the 
  range, 
  

   Anabrus 
  purpurascens 
  prevailed, 
  no 
  specimens 
  of 
  Anabrus 
  simplex 
  appear- 
  

   ing 
  $ 
  while, 
  on 
  the 
  other 
  hand, 
  when 
  he 
  passed 
  to 
  the 
  next 
  side 
  Anabrus 
  

   simplex 
  prevailed, 
  no 
  specimens 
  of 
  A. 
  purpurascens 
  appearing. 
  He 
  never 
  

   knew 
  of 
  any 
  exception 
  to 
  this 
  rule. 
  Our 
  own 
  observations 
  and 
  the 
  re- 
  

   corded 
  statements 
  of 
  others 
  bear 
  out 
  this 
  conclusion. 
  211 
  

  

  So 
  far 
  as 
  ascertained, 
  the 
  northern 
  limits 
  of 
  distribution 
  of 
  Anabrus 
  

  

  210 
  While 
  the 
  distribution 
  of 
  the 
  Rocky 
  Mountain 
  locust 
  has 
  been 
  given 
  in 
  the 
  First 
  Report 
  of 
  this 
  

   Commission 
  and 
  mapped, 
  tlic 
  general 
  characteristics 
  distinguishing 
  the 
  central 
  province 
  from 
  the 
  

   eastern 
  and 
  Pacific 
  or 
  western, 
  have 
  been 
  briefly 
  discussed 
  in 
  the 
  American 
  Naturalist 
  for 
  August, 
  

   1878; 
  the 
  species 
  of 
  Anabrus 
  may 
  be 
  added 
  to 
  tho 
  insects 
  there 
  enumerated. 
  

  

  211 
  Mr. 
  Thomas 
  has 
  observed 
  A. 
  purpurascens 
  at 
  the 
  following 
  places 
  in 
  addition 
  to 
  Colorado, 
  to 
  wit: 
  

   Nebraska; 
  Southeast 
  Dakota, 
  to 
  tho 
  west 
  boundary 
  of 
  Minnesota; 
  on 
  tho 
  Sweetwater, 
  in 
  Wyoming 
  ; 
  

   also 
  in 
  Montana, 
  from 
  Pleasant 
  Valley, 
  where 
  wo 
  cross 
  the 
  range 
  to 
  Virginia 
  City. 
  

  

  