﻿INVESTIGATIONS 
  INTO 
  THE 
  BIONOMICS 
  OP 
  GLOSSINA 
  PALPALIS. 
  

  

  361 
  

  

  From 
  the 
  22nd 
  December 
  the 
  wild 
  hosts 
  (crocodile 
  and 
  Varanus) 
  were 
  systema- 
  

   tically 
  hunted 
  from 
  the 
  island. 
  The 
  effect 
  on 
  the 
  behaviour 
  of 
  fly 
  toward 
  the 
  

   tethered 
  host 
  animals 
  was 
  not 
  noticeable 
  on 
  the 
  first 
  day, 
  but 
  appeared 
  on 
  the 
  second 
  

   in 
  the 
  increased 
  number 
  engorging 
  upon 
  them. 
  The 
  third 
  day 
  was 
  overcast 
  and 
  

   flies 
  were 
  inactive, 
  but 
  on 
  the 
  fourth 
  day, 
  as 
  may 
  be 
  seen 
  from 
  Table 
  IX, 
  a 
  very 
  

   notable 
  increase 
  in 
  the 
  number 
  of 
  flies 
  engorging 
  was 
  brought 
  about. 
  

  

  The 
  percentage 
  of 
  females 
  was 
  determined 
  anew 
  on 
  the 
  26th 
  and 
  27th, 
  and 
  was 
  

   found 
  to 
  have 
  increased 
  from 
  15*5 
  to 
  57*2. 
  This 
  was 
  certainly 
  due 
  to 
  decrease 
  in 
  

   number 
  of 
  wild 
  hosts 
  ; 
  the 
  increase 
  in 
  number 
  of 
  flies 
  engorging 
  upon 
  domestic 
  animals 
  

   was 
  certainly 
  due 
  to 
  the 
  same 
  cause, 
  and 
  is 
  thus 
  directly 
  correlated 
  with 
  variations 
  

   in 
  sex 
  ratio. 
  

  

  Table 
  IX. 
  

  

  Showing 
  Effect 
  of 
  hunting 
  Wild 
  Hosts 
  from 
  Lugazi 
  Islet 
  upon 
  Behaviour 
  of 
  

  

  Glossina 
  palpalis 
  toward 
  Goat 
  and 
  Pig. 
  

  

  Conditions 
  on 
  Islet. 
  

  

  Date 
  

  

  (1913). 
  

  

  Pig. 
  

  

  Hours 
  

  

  ex- 
  

   posed. 
  

  

  Flies 
  

   engorg- 
  

   ing. 
  

  

  Bites 
  

  

  per 
  

  

  Hour. 
  

  

  Goat. 
  

  

  Hours 
  

  

  ex- 
  

   posed 
  

  

  Flies 
  

   engorg- 
  

   ing. 
  

  

  Bites 
  

  

  per 
  

  

  Hour. 
  

  

  Wild 
  hosts 
  undisturbed. 
  

   Female 
  rartio 
  15' 
  5 
  %. 
  

  

  Wild 
  hosts 
  hunted. 
  ( 
  

  

  Female 
  ratio 
  increasing 
  

   to 
  57*2 
  %. 
  ( 
  

  

  15th 
  December 
  

  

  16th 
  

  

  17 
  th 
  

  

  18th 
  

  

  19th 
  

  

  20th 
  

  

  22nd 
  

  

  23rd 
  

  

  24th 
  

  

  25th 
  

  

  

  - 
  — 
  ■ 
  

  

  — 
  

  

  - 
  — 
  ■ 
  

  

  2 
  

   8 
  

  

  - 
  — 
  - 
  

  

  4 
  

  

  

  

  

  

  

  

  3| 
  

  

  — 
  

  

  — 
  

  

  7i 
  

  

  — 
  

  

  8 
  

  

  1 
  

  

  •12 
  

  

  16 
  

  

  ■ 
  — 
  - 
  

  

  8 
  

  

  — 
  

  

  ■ 
  — 
  - 
  

  

  16 
  

  

  — 
  

  

  8£ 
  

  

  • 
  — 
  ■ 
  

  

  — 
  

  

  17 
  

  

  — 
  

  

  18 
  

  

  5 
  

  

  •28 
  

  

  18 
  

  

  3 
  

  

  17 
  

  

  4 
  

  

  •24 
  

  

  17 
  

  

  2 
  

  

  18 
  

  

  49 
  

  

  2-72 
  

  

  18 
  

  

  6 
  

  

  •17 
  

   •12 
  

   •33 
  

  

  The 
  behaviour 
  of 
  fly 
  toward 
  man 
  underwent 
  a 
  change 
  quite 
  as 
  striking 
  as 
  in 
  its 
  

   behaviour 
  toward 
  pig. 
  At 
  first 
  it 
  was 
  attempted 
  to 
  keep 
  an 
  exact 
  record 
  of 
  the 
  

   number 
  of 
  flies 
  attacking 
  the 
  observer 
  and 
  the 
  fly 
  boys. 
  From 
  the 
  15th 
  to 
  the 
  20th 
  

   inclusive 
  only 
  one 
  fly 
  bit 
  and 
  none 
  engorged 
  upon 
  the 
  observer. 
  The 
  fly 
  boys 
  

   were 
  equally 
  immune. 
  During 
  this 
  period 
  no 
  one 
  paid 
  any 
  attention 
  to 
  the 
  fly 
  nor 
  

   was 
  any 
  effort 
  required 
  to 
  ward 
  it 
  off. 
  

  

  On 
  the 
  22nd 
  December 
  no 
  difference 
  was 
  noted 
  and 
  no 
  flies 
  bit 
  the 
  observer. 
  

  

  On 
  the 
  23rd 
  " 
  Flies 
  were 
  more 
  active 
  than 
  I 
  have 
  seen 
  them." 
  Four 
  flies 
  bit 
  the 
  

   observer. 
  

  

  The 
  24th 
  was 
  a 
  dull 
  day. 
  " 
  Flies 
  very 
  inactive 
  but 
  bothersome. 
  Four 
  flies 
  

   bit 
  ; 
  others 
  would 
  have 
  bitten 
  if 
  permitted 
  to 
  do 
  so." 
  The 
  fly 
  boys 
  were 
  equally 
  

   annoyed, 
  and 
  considerable 
  effort 
  was 
  required 
  to 
  keep 
  flies 
  at 
  a 
  distance. 
  

  

  On 
  the 
  25th 
  it 
  was 
  necessary 
  to 
  be 
  constantly 
  on 
  guard 
  against 
  the 
  flies. 
  " 
  The 
  

   flies 
  are 
  hungry 
  — 
  very 
  hungry. 
  They 
  attack 
  man 
  viciously, 
  and 
  it 
  is 
  impossible 
  

   to 
  estimate 
  the 
  number 
  of 
  times 
  I 
  have 
  been 
  bitten 
  or 
  would 
  have 
  been 
  bitten 
  but 
  

  

  