﻿INVESTIGATIONS 
  INTO 
  THE 
  BIONOMICS 
  OF 
  GLOSSINA 
  PALPALIS. 
  

  

  355 
  

  

  1(6). 
  Relative 
  Inactivity 
  of 
  Females 
  of 
  Glossina 
  palpalis 
  as 
  the 
  Explanation 
  of 
  

   Low 
  Female 
  Percentage 
  in 
  Catch. 
  

  

  The 
  figures 
  of 
  the 
  catches 
  of 
  fly 
  from 
  Bulago 
  and 
  Tavu 
  Islands 
  presented 
  in 
  

   Table 
  I 
  show 
  a 
  discrepancy 
  in 
  that 
  the 
  percentage 
  of 
  females 
  in 
  the 
  total 
  catch 
  

   from 
  Bulago 
  Island 
  tended 
  to 
  fall 
  as 
  the 
  total 
  grew, 
  whereas 
  on 
  Tavu 
  it 
  rose 
  sharply. 
  

   This 
  might 
  be 
  accidental, 
  but 
  the 
  circumstances 
  under 
  which 
  the 
  experiment 
  

   was 
  conducted 
  indicated 
  otherwise. 
  Tavu 
  Island 
  is 
  much 
  smaller 
  than 
  Bulago, 
  

   and 
  the 
  catching 
  of 
  some 
  1,300 
  flies 
  on 
  the 
  5th 
  and 
  6th 
  of 
  November 
  seemed 
  

   to 
  have 
  reduced 
  the 
  local 
  density 
  of 
  the 
  species 
  appreciably, 
  as 
  measured 
  by 
  the 
  

   average 
  number 
  of 
  flies 
  which 
  could 
  be 
  caught 
  per 
  boy 
  per 
  hour. 
  A 
  corps 
  of 
  9 
  

   or 
  10 
  boys 
  was 
  employed. 
  During 
  these 
  first 
  days 
  of 
  the 
  investigations 
  the 
  exact 
  

   time 
  spent 
  in 
  catching 
  was 
  not 
  recorded. 
  It 
  was 
  approximately 
  known, 
  however, 
  

   and 
  when 
  the 
  catch 
  of 
  males 
  and 
  females 
  per 
  boy 
  per 
  hour 
  (approximately) 
  is 
  

   tabulated 
  it 
  stands 
  as 
  in 
  Table 
  V. 
  

  

  Table 
  V. 
  

  

  Reduction 
  in 
  Density 
  of 
  Glossina 
  palpalis 
  on 
  Tavu 
  Island 
  due 
  to 
  catching 
  

  

  of 
  Fly. 
  

  

  1913. 
  

  

  Catch 
  of 
  Fly. 
  

  

  "Boy 
  

   Hours." 
  

  

  Density 
  of 
  Fly 
  Indicated. 
  

  

  

  Males. 
  | 
  Females. 
  

  

  i 
  • 
  i 
  

   Males. 
  J 
  Females. 
  Total. 
  

  

  i 
  

  

  6th 
  November 
  . 
  . 
  

  

  7th 
  

  

  8th 
  

  

  1081 
  

   734 
  

  

  698 
  

  

  98 
  

   169 
  

   111 
  

  

  36 
  

   45 
  

   45 
  

  

  30-0 
  

   16-3 
  

   15-1 
  

  

  2-7 
  

   3*7 
  

   2-5 
  

  

  32*7 
  

  

  20-0 
  

   17-6 
  

  

  Table 
  VI. 
  

  

  Catch 
  of 
  Glossina 
  palpalis 
  on 
  Lula 
  Islet, 
  showing 
  the 
  relative 
  Inactivity 
  of 
  

  

  Females. 
  

  

  Period 
  

  

  

  

  Catch 
  for 
  Period. 
  

  

  Catch 
  to 
  end 
  of 
  Period. 
  

  

  (November 
  1913). 
  

  

  Males. 
  

  

  Fe- 
  

   males. 
  

  

  Female 
  

   Eatio. 
  

  

  Total. 
  

  

  Females. 
  

  

  18th 
  Afternoon 
  . 
  

  

  19th 
  Mor 
  ing 
  . 
  

  

  19th 
  Afternoon 
  . 
  

  

  20th 
  Morning 
  . 
  

  

  20th 
  Afternoon 
  . 
  

  

  21st 
  All 
  Day 
  . 
  

  

  22nd 
  „ 
  

  

  24th 
  „ 
  

  

  25th 
  

  

  26th 
  

  

  27th 
  Morning 
  

  

  

  

  • 
  • 
  

  

  280 
  

   308 
  

  

  93 
  

  

  83 
  

  

  36 
  

  

  95 
  

  

  51 
  

  

  29* 
  

  

  28* 
  

  

  29* 
  

  

  17 
  

  

  18 
  

  

  72 
  

   68 
  

  

  146 
  

   89 
  

  

  224 
  

   79 
  

   73 
  

   93 
  

   65 
  

   53 
  

  

  6-0 
  % 
  

   19-0 
  % 
  

   42-2 
  % 
  

   64-3 
  % 
  

   71-2 
  % 
  

   70-2 
  % 
  

   60-8 
  % 
  

   71-5 
  % 
  

   76-9 
  % 
  

   69-1 
  % 
  

   75-7 
  % 
  

  

  298 
  

   678 
  

   839 
  

   1068 
  

   1193 
  

   J512 
  

   1642 
  

   1744 
  

   1865 
  

   1959 
  

   2029 
  

  

  6-0 
  % 
  

   13-3 
  % 
  

   18-8 
  % 
  

   28-5 
  % 
  

   32-9 
  % 
  

   40-8 
  % 
  

   42-4 
  % 
  

   43-5 
  % 
  

   46-2 
  % 
  

   47'3 
  % 
  

   483 
  % 
  

  

  * 
  These 
  figures, 
  apparently, 
  represent 
  about 
  the 
  daily 
  emergence 
  of 
  males 
  from 
  pupae; 
  

   all 
  the 
  old 
  flies 
  of 
  this 
  sex 
  appear 
  to 
  have 
  been 
  caught 
  off. 
  

  

  