﻿REPORT 
  OF 
  TSETSE-FLY 
  INVESTIGATION 
  IN 
  NIGERIA. 
  

  

  389 
  

  

  - 
  No 
  mature 
  infection 
  of 
  the 
  brucei-gambiense 
  group 
  has 
  been 
  met 
  with 
  in 
  dis- 
  

   section, 
  but 
  a 
  member 
  of 
  the 
  group 
  has 
  been 
  recovered 
  from 
  wild 
  G. 
  tachinoides 
  

   by 
  feeding 
  freshly 
  caught 
  wild 
  flies 
  on 
  a 
  healthy 
  dog 
  at 
  Mashiwashi. 
  

  

  T. 
  pecorum 
  and 
  a 
  member 
  of 
  the 
  vivax 
  gfoup, 
  probably 
  T. 
  vivax, 
  have 
  been 
  

   definitely 
  identified 
  both 
  in 
  salivary 
  drops 
  and 
  in 
  proboscides 
  in 
  several 
  G. 
  palpalis, 
  

   arid 
  in 
  many 
  instances 
  in 
  G. 
  tachinoides 
  and 
  G. 
  morsitans. 
  Both 
  T. 
  pecorum 
  and 
  

   T. 
  vivax 
  have 
  been 
  recovered 
  from 
  G. 
  tachinoides 
  by 
  feeding 
  freshly 
  caught 
  wild 
  flies 
  

   on 
  sheep 
  at 
  Mashiwashi. 
  

  

  Of 
  552 
  palpalis 
  examined, 
  trypanosomes 
  were 
  found 
  in 
  31, 
  distributed 
  as 
  follows 
  : 
  

   mid-gut 
  only, 
  16 
  ; 
  gut, 
  proventriculus 
  and 
  proboscis, 
  3 
  ; 
  proboscis 
  only, 
  12. 
  

   (Table 
  IV.) 
  

  

  Of 
  1,500 
  tachinoides 
  examined, 
  trypanosomes 
  were 
  found 
  in 
  170, 
  distributed 
  as 
  

   follows 
  : 
  mid-gut 
  only, 
  72 
  ; 
  gut, 
  proventriculus 
  and 
  proboscis, 
  16 
  ; 
  proboscis 
  

   only, 
  82. 
  (Table 
  IV.) 
  

  

  Of 
  500 
  morsitans 
  examined, 
  trypanosomes 
  were 
  found 
  in 
  132, 
  distributed 
  as 
  

   follows: 
  mid-gut 
  only, 
  26; 
  gut, 
  proventriculus 
  and 
  ' 
  proboscis, 
  30; 
  proboscis 
  

   only, 
  76. 
  (Table 
  IV.) 
  

  

  Of 
  14 
  longipalpis 
  examined, 
  trypanosomes 
  were 
  found 
  in 
  the 
  salivary 
  drop 
  of 
  

   1, 
  these 
  being 
  ghost-like 
  as 
  described 
  above 
  but 
  morphologically 
  resembling 
  the 
  

   infective 
  forms 
  of 
  T. 
  vivax, 
  but 
  not 
  certainly 
  identified 
  as 
  such. 
  

  

  TABLE 
  IV. 
  

  

  Showing 
  the 
  Proportion 
  of 
  G. 
  palpalis, 
  tachinoides 
  and 
  morsitans 
  injected 
  with 
  Trypanosomes, 
  

  

  and 
  their 
  Situation 
  in 
  the 
  Flies. 
  

  

  Species. 
  

  

  Number 
  

   dissected. 
  

  

  Number 
  

  

  showing 
  

  

  trypanosomes 
  

  

  Total 
  

  

  percentage 
  

  

  infected. 
  

  

  Situation 
  of 
  trypanosomes 
  in 
  

   the 
  flies 
  (percentages). 
  

  

  Gut 
  

   only. 
  

  

  Gut 
  and 
  

   proboscis. 
  

  

  Proboscis 
  

   only. 
  

  

  G. 
  palpalis 
  

   G. 
  tachinoides 
  

   G. 
  morsitans 
  

  

  552 
  

  

  1,500 
  

  

  500 
  

  

  31 
  

   170 
  

   132 
  

  

  5-6 
  

   113 
  

   26-4 
  

  

  2-9 
  

   4-8 
  

   5-2 
  

  

  0-5 
  

   1-1 
  

   60 
  

  

  2-2 
  

  

  5-4 
  

  

  15-2 
  

  

  Wherever 
  morsitans 
  and 
  tachinoides 
  were 
  found 
  together, 
  a 
  series 
  of 
  each 
  species 
  

   was 
  dissected 
  in 
  order 
  that 
  their 
  infections 
  and 
  food 
  might 
  be 
  contrasted. 
  The 
  

   total 
  percentage 
  of 
  flagellate 
  infections 
  in 
  663 
  tachinoides 
  was 
  12, 
  and 
  that 
  in 
  471 
  

   morsitans 
  was 
  25. 
  These 
  data 
  are 
  collected 
  from 
  six 
  different 
  localities, 
  each 
  of 
  

   which 
  gives 
  much 
  the 
  same 
  result, 
  viz., 
  that 
  when 
  the 
  two 
  species 
  are 
  found 
  in 
  the 
  

   same 
  area 
  the 
  flagellate 
  infections 
  of 
  morsitans 
  are 
  about 
  double 
  those 
  of 
  tachinoides. 
  

  

  Table 
  V 
  further 
  contrasts 
  these 
  infections 
  in 
  the 
  two 
  species, 
  all 
  that 
  were 
  

   examined 
  being 
  included, 
  and 
  tachinoides 
  being 
  divided 
  into 
  two 
  classes 
  according 
  

   as 
  to 
  whether 
  they 
  were 
  collected 
  in 
  areas 
  where 
  big 
  game 
  is 
  absent 
  and 
  small 
  game 
  

   virtually 
  so, 
  or 
  in 
  areas 
  where 
  big 
  game 
  was 
  present 
  and 
  small 
  antelopes 
  and 
  pig 
  

   correspondingly 
  numerous. 
  The 
  infections 
  are 
  classified 
  according 
  to 
  the 
  location 
  

   of 
  the 
  trypanosomes 
  in 
  the 
  fly. 
  In 
  the 
  populous 
  districts 
  with 
  scanty 
  small 
  game 
  

   but 
  numerous 
  domestic 
  animals 
  tachinoides 
  shows 
  a 
  heavy 
  percentage 
  of 
  gut 
  infec- 
  

   tions, 
  with 
  few 
  in 
  the 
  proboscis. 
  In 
  the 
  game 
  areas 
  the 
  infections 
  of 
  the 
  gut 
  only 
  

  

  (8455) 
  2 
  e 
  

  

  