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  OBSERVATIONS 
  ON 
  GLOSSINA 
  MORSITANS 
  IN 
  NORTHERN 
  

  

  RHODESIA. 
  

  

  The 
  British 
  South 
  Africa 
  Company 
  have 
  recently 
  received 
  a 
  report 
  from 
  Mr. 
  

   R. 
  A. 
  F. 
  Eminson, 
  one 
  of 
  the 
  three 
  Entomologists 
  whom 
  they 
  have 
  engaged 
  for 
  the- 
  

   special 
  study 
  of 
  the 
  bionomics 
  of 
  Glossina 
  morsitans 
  in 
  Northern 
  Rhodesia, 
  upon 
  

   the 
  work 
  done 
  by 
  him 
  from 
  May 
  to 
  July, 
  1914. 
  

  

  In 
  the 
  course 
  of 
  his 
  remarks 
  on 
  breeding 
  places 
  Mr. 
  Eminson 
  states 
  that 
  he 
  has 
  

   not 
  yet 
  succeeded 
  in 
  ascertaining 
  definitely 
  why 
  certain 
  spots 
  are 
  specially 
  preferred 
  

   by 
  G. 
  morsitans 
  for 
  breeding 
  purposes 
  ; 
  but 
  two 
  negative 
  points 
  are 
  noted, 
  namely, 
  

   that 
  in 
  country 
  otherwise 
  suitable, 
  no 
  favoured 
  breeding 
  places 
  have 
  been 
  found 
  in 
  

   any 
  localities 
  in 
  which 
  there 
  was 
  any 
  depth 
  of 
  sandy 
  soil, 
  or 
  in 
  which 
  there 
  was 
  a 
  

   dense 
  growth 
  of 
  long 
  grass. 
  Although 
  a 
  search 
  was 
  made 
  for 
  pupae 
  over 
  a 
  con- 
  

   siderable 
  area, 
  the 
  great 
  majority 
  were 
  found 
  within 
  a 
  comparatively 
  restricted 
  space. 
  

   This 
  favoured 
  area 
  is 
  described 
  as 
  being 
  " 
  uniformly 
  covered 
  with 
  forest 
  trees 
  ; 
  

   very 
  little 
  grass 
  grows 
  amongst 
  the 
  trees, 
  and 
  that 
  little 
  is 
  short 
  ; 
  the 
  soil 
  is 
  of 
  a 
  

   sandy 
  gravelly 
  nature 
  and 
  very 
  thin, 
  merely 
  covering 
  the 
  underlying 
  granite 
  which 
  

   crops 
  out 
  in 
  places. 
  The 
  surface 
  of 
  the 
  ground 
  shows 
  a 
  gentle 
  slope 
  in 
  a 
  north- 
  

   westerly 
  direction 
  to 
  a 
  vlei 
  [open, 
  moist, 
  low-lying 
  land] 
  in 
  which 
  a 
  little 
  water 
  

   stands 
  in 
  the 
  wet 
  season, 
  but 
  which 
  is 
  completely 
  dry 
  at 
  this 
  season 
  [mid- 
  winter]. 
  

   I 
  cannot 
  say 
  that 
  I 
  have 
  noticed 
  much 
  spoor 
  of 
  game, 
  except 
  some 
  impala 
  and 
  wart- 
  

   hog 
  ; 
  certainly 
  I 
  should 
  not 
  say 
  that 
  there 
  was 
  any 
  more 
  game 
  than 
  in 
  the 
  surrounding 
  

   country, 
  if 
  as 
  much. 
  The 
  breeding 
  places 
  which 
  yielded 
  the 
  greatest 
  number 
  of 
  

   pupae 
  and 
  empty 
  pupa-cases 
  were 
  situated 
  near 
  the 
  path 
  ; 
  the 
  fly 
  had 
  evidently 
  been 
  

   feeding 
  on 
  game, 
  or 
  more 
  probably 
  human 
  beings, 
  preparatory 
  to 
  depositing 
  their 
  

   larvae." 
  

  

  It 
  is 
  noted 
  that 
  many 
  of 
  the 
  logs 
  under 
  which 
  large 
  numbers 
  of 
  pupae 
  were 
  found 
  

   were 
  devoid 
  of 
  bark, 
  and 
  in 
  Mr. 
  Eminson's 
  opinion, 
  the 
  female 
  tsetses 
  prefer 
  a 
  smooth 
  

   barkless 
  log 
  on 
  which 
  to 
  rest 
  before 
  depositing 
  their 
  larvae. 
  They 
  also 
  show 
  a 
  

   preference 
  for 
  a 
  log 
  which 
  in 
  some 
  part 
  of 
  its 
  length 
  is 
  raised 
  a 
  few 
  inches 
  above 
  the 
  

   ground, 
  thus 
  affording 
  a 
  shady 
  resting 
  place 
  ; 
  a 
  point 
  which 
  has 
  already 
  been 
  empha- 
  

   sised 
  by 
  Mr. 
  Llewellyn 
  Lloyd. 
  

  

  An 
  account 
  is 
  given 
  of 
  some 
  experiments 
  in 
  feeding 
  captive 
  flies 
  on 
  avian 
  blood 
  

   only, 
  but 
  the 
  results 
  are 
  vitiated 
  by 
  the 
  fact 
  that 
  the 
  insects 
  were 
  kept 
  in 
  cages 
  which 
  

   were 
  clearly 
  unsuitable. 
  In 
  any 
  case, 
  laboratory 
  experiments 
  of 
  this 
  kind 
  can 
  never 
  

   be 
  regarded 
  as 
  entirely 
  satisfactory. 
  

  

  A 
  much 
  safer 
  method 
  of 
  arriving 
  at 
  the 
  normal 
  food 
  of 
  Glossina 
  is 
  by 
  an 
  examination 
  

   of 
  the 
  gut 
  contents 
  of 
  captured 
  flies 
  in 
  various 
  conditions 
  of 
  environment. 
  During 
  

   May 
  1914, 
  300 
  flies 
  were 
  examined 
  for 
  this 
  purpose, 
  and 
  recognisable 
  blood 
  was. 
  

   found 
  in 
  43 
  ; 
  of 
  these, 
  41 
  contained 
  mammalian 
  and 
  2 
  non-mammalian 
  blood, 
  so 
  

   that 
  the 
  latter 
  amounted 
  to 
  5 
  per 
  cent. 
  It 
  is 
  stated 
  that 
  a 
  similar 
  investigation 
  

   during 
  the 
  wet 
  season 
  months 
  of 
  February 
  and 
  March 
  yielded 
  only 
  1 
  per 
  cent, 
  of 
  flies, 
  

   containing 
  non-mammalian 
  blood, 
  but 
  the 
  actual 
  numbers 
  are 
  not 
  given. 
  As 
  a 
  

   possible 
  explanation 
  of 
  this 
  difference, 
  it 
  is 
  suggested 
  that 
  the 
  flies 
  are 
  probably 
  

  

  