﻿AND 
  BIG 
  GAME 
  IN 
  S. 
  RHODESIA. 
  107 
  

  

  bloodsucking 
  flies 
  would 
  seem 
  to 
  be 
  beyond 
  question, 
  when 
  we 
  consider 
  how 
  little 
  

   attention 
  Stomoxys, 
  Haematopota, 
  Tabanus, 
  etc., 
  pay 
  to 
  fowls, 
  for 
  instance, 
  even 
  in 
  

   the 
  absence 
  of 
  larger 
  animals. 
  The 
  only 
  bloodsucking 
  flies 
  that 
  have 
  made 
  a 
  thorough 
  

   success 
  of 
  feeding 
  on 
  birds 
  appear 
  to 
  be 
  some 
  members 
  of 
  the 
  Hippoboscidae, 
  which 
  

   have 
  developed 
  a 
  parasitic 
  habit 
  and 
  become 
  specially 
  adapted 
  to 
  moving 
  about 
  

   amongst 
  feathers. 
  The 
  flat 
  form 
  of 
  Olfersia 
  is 
  obviously 
  of 
  advantage 
  to 
  it 
  in 
  this 
  

   respect, 
  and 
  we 
  can 
  see 
  how 
  ill-adapted 
  the 
  tsetse 
  is 
  in 
  comparison. 
  

  

  With 
  regard 
  to 
  the 
  smaller 
  antelopes 
  and 
  Quadrumana 
  there 
  is 
  no 
  doubt 
  at 
  all 
  

   that 
  the 
  fly 
  feeds 
  upon 
  these 
  animals 
  whenever 
  appetite 
  and 
  opportunity 
  coincide, 
  or 
  

   that 
  a 
  regular 
  supply 
  of 
  the 
  blood 
  of 
  these 
  species 
  would 
  serve 
  the 
  fly 
  indefinitely. 
  

   The 
  small 
  buck, 
  such 
  as 
  Cervicapra 
  and 
  Cephalophus, 
  however, 
  do 
  not 
  run 
  in 
  herds 
  and 
  

   are 
  very 
  scattered, 
  and 
  on 
  this 
  account 
  are 
  not 
  fitted 
  to 
  afford 
  a 
  regular 
  meal 
  to 
  large 
  

   quantities 
  of 
  tsetse. 
  It 
  is 
  conceivable 
  that 
  monkeys 
  and 
  baboons, 
  in 
  spite 
  of 
  the 
  

   great 
  troops 
  of 
  the 
  latter, 
  also 
  fail 
  to 
  some 
  extent 
  in 
  this 
  respect. 
  They 
  are 
  also 
  by 
  

   no 
  means 
  constant 
  denizens 
  of 
  fly-belts.* 
  

  

  A 
  feasible 
  explanation 
  of 
  the 
  dependence 
  of 
  G. 
  morsitans 
  on 
  the 
  larger 
  Ungulata 
  

   seems 
  to 
  be 
  that 
  a 
  regular 
  supply 
  of 
  blood 
  is 
  essential 
  to 
  the 
  continuance 
  of 
  the 
  fly, 
  

   and 
  that 
  this 
  is 
  only 
  afforded 
  by 
  the 
  presence 
  during 
  the 
  greater 
  part 
  of 
  the 
  year 
  of 
  

   these 
  grass-feeding 
  animals. 
  An 
  irregular 
  supply 
  is 
  afforded 
  by 
  monkeys, 
  baboons, 
  

   small 
  buck 
  and 
  other 
  animals, 
  and 
  possibly 
  birds, 
  which 
  may 
  help 
  to 
  tide 
  the 
  insect 
  

   over 
  periods 
  of 
  scarcity. 
  It 
  does 
  not 
  appear 
  to 
  be 
  incomprehensible 
  that 
  a 
  regular 
  

   supply 
  of 
  food 
  should 
  be 
  of 
  such 
  importance 
  to 
  the 
  species 
  when 
  we 
  recollect 
  the 
  great 
  

   expenditure 
  of 
  substance 
  of 
  the 
  female 
  in 
  the 
  comparatively 
  slow 
  process 
  of 
  repro- 
  

   duction. 
  The 
  tsetse 
  is 
  obviously 
  very 
  delicately 
  poised 
  in 
  the 
  balance 
  of 
  nature, 
  and 
  

   any 
  retardation 
  of 
  the 
  rate 
  of 
  reproduction 
  would 
  obviously 
  have 
  a 
  tendency 
  to 
  result 
  

   in 
  the 
  failure 
  of 
  the 
  species 
  to 
  maintain 
  itself. 
  When 
  food 
  is 
  scarce 
  there 
  is 
  no 
  doubt 
  

   that 
  reproduction 
  is 
  retarded, 
  and 
  in 
  belts 
  where 
  a 
  season 
  of 
  scarcity 
  occurs 
  annually 
  

   there 
  will 
  be 
  comparatively 
  few 
  offspring 
  produced 
  during 
  certain 
  seasons 
  of 
  the 
  year. 
  

   The 
  very 
  few 
  pupae 
  found 
  by 
  the 
  writer 
  on 
  the 
  thickly 
  infested 
  Gorai 
  River 
  supports 
  

   this 
  view, 
  especially 
  when 
  compared 
  with 
  the 
  results 
  obtained 
  elsewhere 
  in 
  belts 
  not 
  

   subjected 
  to 
  annual 
  periods 
  of 
  dearth. 
  During 
  a 
  portion 
  of 
  the 
  time 
  when 
  the 
  flies 
  

   are 
  congregated 
  in 
  the 
  shade 
  provided 
  by 
  the 
  banks 
  of 
  the 
  watercourses 
  reproduction 
  

   is 
  apparently 
  very 
  slow, 
  and 
  it 
  must 
  be 
  assumed 
  that 
  the 
  numbers 
  of 
  the 
  tsetse 
  are 
  

   maintained 
  by 
  the 
  breeding 
  which 
  occurs 
  at 
  other 
  times 
  of 
  the 
  year. 
  Where, 
  by 
  the 
  

   removal 
  of 
  the 
  main 
  source 
  of 
  food, 
  tsetse 
  is 
  subjected 
  permanently 
  to 
  an 
  irregular 
  

   supply 
  and 
  also 
  forced 
  to 
  draw 
  this 
  from 
  sources 
  involving 
  some 
  danger 
  to 
  the 
  fly 
  

   itself, 
  reproduction 
  could 
  quite 
  conceivably 
  fail 
  to 
  keep 
  pace 
  with 
  the 
  death 
  rate, 
  and 
  

   the 
  species 
  die 
  out 
  on 
  this 
  account. 
  

  

  The 
  writer 
  would 
  emphasise 
  the 
  fact 
  that 
  no 
  claim 
  is 
  made 
  to 
  have 
  explained 
  in 
  the 
  

   foregoing 
  pages 
  all 
  the 
  phenomena 
  connected 
  with 
  the 
  disappearance 
  of 
  tsetse-fly. 
  

   There 
  are 
  far 
  too 
  many 
  factors 
  affecting 
  the 
  situation. 
  Nor 
  does 
  he 
  hesitate 
  to 
  admit, 
  

   first, 
  that 
  there 
  are 
  many 
  abler 
  students 
  who 
  could 
  have 
  handled 
  the 
  subject 
  with 
  far 
  

   more 
  knowledge 
  and 
  dexterity 
  than 
  himself 
  ; 
  and 
  secondly, 
  that 
  many 
  of 
  his 
  

  

  * 
  Dr. 
  R. 
  E. 
  McConnelTs 
  observations 
  on 
  the 
  actions 
  of 
  his 
  pet 
  monkeys 
  when 
  attacked 
  

   by 
  tsetse 
  show 
  that 
  making 
  a 
  meal 
  of 
  monkey's 
  blood 
  is 
  not 
  without 
  danger 
  to 
  the 
  fly 
  

   itself. 
  In 
  connexion 
  with 
  a 
  species 
  to 
  which 
  the 
  prolonged 
  survival 
  of 
  the 
  individual 
  is 
  of 
  

   such 
  importance 
  as 
  it 
  is 
  for 
  Glossina, 
  this 
  may 
  not 
  be 
  without 
  significance. 
  

  

  