﻿652 
  REPORT 
  UNITED 
  STATES 
  GEOLOGICAL 
  SURVEY. 
  

  

  stateraeDts 
  of 
  authors 
  are 
  at 
  variance. 
  The 
  observations 
  of 
  Sydon 
  and 
  

   Bonzingk 
  give 
  about 
  a 
  quarter 
  of 
  a 
  German 
  mile 
  {i. 
  e., 
  about 
  0.975 
  mile 
  

   Englisli) 
  in 
  the 
  hour. 
  Techemewsky 
  asserts 
  that 
  they 
  only 
  advance 
  

   about 
  350 
  feet 
  in 
  the 
  day 
  upon 
  grass 
  land. 
  

  

  Of 
  the 
  senses 
  of 
  the 
  locust, 
  Koppen 
  seems 
  to 
  regard 
  hearing 
  as 
  the 
  

   sharpest. 
  The 
  senses 
  of 
  smell 
  and 
  taste 
  are 
  exerted 
  in 
  the 
  selection 
  of 
  

   food 
  ; 
  and 
  that 
  of 
  touch 
  is 
  displayed 
  in 
  the 
  sensibility 
  of 
  the 
  insects 
  to 
  

   changes 
  of 
  weather, 
  especially 
  temperature. 
  Sociability 
  is 
  regarded 
  by 
  

   the 
  author 
  as 
  characteristic 
  of 
  the 
  locusts. 
  The 
  larvje 
  proceeding 
  from 
  

   one 
  nest 
  seem 
  to 
  keep 
  together 
  for 
  a 
  time 
  ; 
  they 
  afterward 
  associate 
  in 
  

   larger 
  masses 
  which 
  move 
  together 
  in 
  search 
  of 
  nourishment. 
  These 
  

   migrations 
  in 
  mass 
  commence 
  in 
  the 
  second 
  stage 
  of 
  larval 
  life, 
  but 
  be- 
  

   come 
  more 
  general 
  after 
  the 
  second 
  moult. 
  The 
  migration 
  usually 
  takes 
  

   place 
  in 
  the 
  morning 
  and 
  evening. 
  The 
  author 
  remarks 
  upon 
  the 
  direc- 
  

   tion 
  of 
  the 
  migrations 
  of 
  these 
  insects, 
  which 
  he 
  regards 
  as 
  influenced 
  

   to 
  a 
  certain 
  extent 
  by 
  an 
  instinctive 
  perception 
  of 
  the 
  direction 
  in 
  which 
  

   abundant 
  food 
  or 
  a 
  suitable 
  breeding-place 
  is 
  to 
  be 
  found, 
  but 
  modified 
  

   or 
  even 
  sometimes 
  caused 
  by 
  external 
  agents, 
  especially 
  the 
  winds. 
  

   The 
  author 
  also 
  discusses 
  the 
  primary 
  causes 
  of 
  the 
  great 
  migrations 
  

   of 
  these 
  insects 
  and 
  the 
  phenomena 
  observed 
  during 
  their 
  flight. 
  

  

  In 
  the 
  south 
  of 
  Russia 
  the 
  hatching 
  of 
  the 
  eggs 
  takes 
  place, 
  according 
  

   to 
  the 
  weather, 
  at 
  the 
  end 
  of 
  April 
  or 
  beginning 
  of 
  May. 
  A 
  few 
  larvas 
  

   are 
  sometimes 
  produced 
  on 
  warm 
  days 
  in 
  October, 
  but 
  these 
  soon 
  die. 
  

   The 
  hatching 
  occupies 
  from 
  two 
  to 
  three 
  weeks, 
  according 
  to 
  circum- 
  

   stances. 
  The 
  winged 
  insects 
  appear 
  in 
  the 
  beginning 
  and 
  middle 
  of 
  

   July; 
  copulation 
  takes 
  place 
  early 
  in 
  August; 
  and 
  theoviposition 
  ex- 
  

   tends 
  from 
  the 
  middle 
  of 
  August 
  to 
  October. 
  The 
  dry 
  steppes 
  con- 
  

   stitute 
  the 
  chief 
  haunt 
  of 
  the 
  locusts 
  ; 
  damp 
  places 
  they 
  seem 
  to 
  avoid. 
  

   The 
  females 
  prefer 
  for 
  the 
  reception 
  of 
  their 
  ova 
  the 
  solid 
  virgin 
  soil, 
  

   and 
  rarely 
  visit 
  ploughed 
  land 
  for 
  this 
  purpose. 
  Damp 
  and 
  cold 
  are 
  

   unfavorable 
  for 
  the 
  development 
  of 
  the 
  eggs. 
  The 
  author 
  discusses 
  in 
  

   great 
  detail 
  the 
  external 
  conditions 
  which 
  act 
  favorably 
  or 
  unfavorably 
  

   upon 
  these 
  insects. 
  The 
  greater 
  part 
  of 
  this 
  section 
  is 
  devoted 
  to 
  the 
  

   consideration 
  of 
  their 
  enemies, 
  of 
  which 
  Koppen 
  gives 
  a 
  formidable 
  

   list 
  (pp. 
  151-166). 
  

  

  Leime 
  and 
  other 
  authors 
  have 
  given 
  Tartary 
  as 
  the 
  true 
  home 
  of 
  the 
  

   migrating 
  locusts; 
  but 
  in 
  Tartary 
  no 
  large 
  swarms 
  occur. 
  In 
  the 
  

   author's 
  opinion, 
  the 
  countries 
  in 
  which 
  the 
  swarms 
  are 
  seen 
  are 
  also 
  

   the 
  countries 
  of 
  their 
  birth. 
  He 
  cites 
  many 
  facts 
  in 
  support 
  of 
  this 
  

   opinion, 
  and 
  in 
  illustration 
  of 
  the 
  geographical 
  distribution 
  of 
  the 
  in- 
  

   sect, 
  the 
  northern 
  limit 
  of 
  their 
  migratory 
  or 
  nomadic 
  life 
  being 
  a 
  line 
  

   passing 
  from 
  Spain 
  through 
  the 
  south 
  of 
  France, 
  Switzerland, 
  Pomera- 
  

   nia, 
  South 
  Russia, 
  and 
  South 
  Siberia, 
  to 
  the 
  north 
  of 
  China. 
  To 
  the 
  

   north 
  of 
  this 
  line 
  the 
  insects 
  generally 
  occur 
  only 
  singly. 
  Many 
  inter- 
  

   esting 
  details 
  as 
  to 
  their 
  occurrence 
  in 
  vast 
  numbers 
  are 
  given 
  by 
  the 
  

   author 
  (pp. 
  190-205). 
  

  

  Koppen 
  also 
  describes 
  the 
  injury 
  done 
  by 
  the 
  locusts 
  when 
  they 
  occur 
  

   in 
  great 
  numbers, 
  and 
  indicates 
  the 
  means 
  adopted 
  for 
  their 
  suppres- 
  

   sion 
  (pp. 
  205-246). 
  

  

  Koppen 
  also 
  notices 
  Caloptemis 
  itaUcns, 
  a 
  congener 
  of 
  our 
  G. 
  spretus, 
  

   which 
  likewise 
  occurs 
  in 
  South 
  Russia, 
  and 
  at 
  such 
  times, 
  as 
  in 
  other 
  

   regions 
  of 
  Southern 
  Europe, 
  sometimes 
  in 
  injurious 
  numbers. 
  Other 
  

   species 
  which 
  are 
  also 
  occasional 
  devastators, 
  especially 
  when 
  asso- 
  

   ciated 
  with 
  the 
  migratory 
  species, 
  are 
  Pachytylus 
  strichtlus, 
  (Edipoda 
  

   vasiator, 
  Stauronotus 
  vastator, 
  S. 
  cruciatus, 
  and 
  Pezotettix 
  alpina. 
  

  

  