﻿REPORT 
  OF 
  TSETSE-FLY 
  INVESTIGATION 
  IN 
  NIGERIA. 
  

  

  379 
  

  

  found. 
  These 
  were 
  mainly 
  concentrated 
  in 
  the 
  wider 
  parts 
  of 
  the 
  bed 
  and 
  pupae 
  

   were 
  almost 
  absent 
  where 
  this 
  became 
  narrow. 
  The 
  shade 
  above 
  them 
  was 
  high 
  

   and 
  moderately 
  dense. 
  This 
  had 
  undoubtedly 
  been 
  the 
  main 
  breeding 
  ground 
  in 
  

   the 
  dry 
  season, 
  the 
  number 
  of 
  empty 
  cases 
  which 
  were 
  found 
  in 
  patches 
  of 
  sand 
  

   outside 
  the 
  bed 
  being 
  negligible. 
  A 
  portion 
  of 
  this 
  breeding 
  ground 
  is 
  shown 
  in 
  

   Plate 
  xxii, 
  fig. 
  2. 
  

  

  Among 
  the 
  pupa-cases 
  collected 
  in 
  this 
  last 
  locality 
  a 
  few 
  of 
  palpalis 
  may 
  be 
  

   included, 
  as 
  this 
  fly 
  was 
  present 
  to 
  the 
  small 
  extent 
  of 
  0-7 
  per 
  cent, 
  among 
  the 
  

   tachinoides. 
  A 
  number 
  of 
  each 
  species 
  were 
  bred 
  out 
  and 
  the 
  cases 
  carefully 
  com- 
  

   pared, 
  but 
  no 
  specific 
  distinguishing 
  characters 
  could 
  be 
  found, 
  differences 
  in 
  size 
  

   and 
  shape 
  being 
  unreliable. 
  

  

  (b) 
  Breeding 
  Season. 
  

  

  After 
  the 
  middle 
  of 
  May 
  at 
  Mashiwashi 
  all 
  the 
  sand 
  became 
  thoroughly 
  wet 
  and 
  

   compact, 
  and 
  pupae 
  or 
  cases 
  were 
  not 
  found 
  except 
  in 
  insignificant 
  numbers 
  in 
  

   sand 
  and 
  none 
  in 
  vegetable 
  debris. 
  

  

  After 
  this 
  date 
  a 
  considerable, 
  though 
  much 
  reduced, 
  number 
  must 
  have 
  been 
  

   deposited, 
  as 
  was 
  indicated 
  by 
  the 
  pregnant 
  condition 
  of 
  many 
  of 
  the 
  females. 
  We 
  

   do 
  not 
  yet 
  know 
  where 
  the 
  pupae 
  are 
  deposited 
  in 
  the 
  rains, 
  but 
  there 
  is 
  much 
  

   evidence 
  of 
  a 
  restraint 
  in 
  the 
  breeding 
  rate. 
  Breeding 
  in 
  the 
  rains 
  seems 
  uneconomical. 
  

   There 
  had 
  already 
  been 
  a 
  heavy 
  storm 
  when 
  work 
  was 
  started 
  at 
  Mashiwashi, 
  and, 
  

   as 
  stated 
  above, 
  of 
  the 
  124 
  whole 
  pupae 
  collected 
  from 
  the 
  stream-bed 
  70 
  per 
  cent, 
  

   contained 
  dead 
  flies, 
  almost 
  certainly 
  killed 
  by 
  the 
  wet, 
  though 
  the 
  water 
  did 
  not 
  

  

  3 
  \J 
  

  

  80 
  

  

  

  

  

  X/ 
  \ 
  A 
  \ 
  

  

  

  

  70 
  

  

  - 
  

  

  

  / 
  • 
  

  

  " 
  v* 
  \ 
  // 
  \ 
  

  

  

  

  

  

  

  jl 
  

  

  

  

  

  

  

  II 
  

  

  * 
  ^^ 
  // 
  \ 
  

  

  

  

  60 
  

  

  

  

  II 
  

   II 
  

  

  

  

  

  50 
  

  

  

  // 
  

  

  

  \ 
  X 
  

  

  \ 
  \ 
  

  

  

  

  40 
  

  

  ■■ 
  

  

  // 
  

   1 
  

   1 
  

  

  ■ 
  

  

  \ 
  \ 
  

  

  

  

  

  

  1 
  

  

  

  VX 
  o-V 
  

  

  . 
  — 
  — 
  o 
  — 
  — 
  

  

  -s 
  

  

  30 
  

  

  ■• 
  

  

  1 
  1 
  

   6 
  1 
  

  

  

  

  

  \ 
  

   \ 
  

   \ 
  

   > 
  

  

  20 
  

  

  

  

  

  .^— 
  _ 
  Represents 
  percentage 
  of 
  fema/es 
  preyn&nt. 
  

   _ 
  Represents 
  tne 
  nutrition 
  of 
  t/ie 
  f/ies. 
  

  

  

  \ 
  

  

  \ 
  

  

  o 
  

  

  10 
  

   n 
  

  

  

  1 
  

  

  I 
  

  

  1 
  1 
  1 
  1 
  1 
  1 
  1 
  

  

  1 
  

  

  1 
  1 
  

  

  Oct 
  

  

  A/on. 
  

  

  Dec. 
  

  

  rebr 
  

  

  April 
  

  

  May 
  

  

  July 
  

  

  log. 
  

  

  Sept. 
  

  

  begin 
  to 
  flow 
  until 
  the 
  end 
  of 
  June. 
  Very 
  prolonged 
  searches 
  by 
  one 
  of 
  us 
  in 
  July 
  

   1921 
  (mid 
  rains) 
  in 
  sand 
  and 
  other 
  materials, 
  in 
  holes 
  in 
  trees 
  and 
  below 
  fallen 
  

   trunks 
  failed 
  to 
  reveal 
  any 
  pupae 
  or 
  cases. 
  A 
  small 
  artificial 
  breeding 
  ground 
  on 
  

   the 
  stream 
  bank 
  (a 
  patch 
  of 
  sand 
  6 
  ft. 
  across 
  with 
  dry 
  palm 
  leaves 
  over 
  it, 
  protected 
  

  

  