﻿INVESTIGATIONS 
  INTO 
  THE 
  BIONOMICS 
  OF 
  GLOSSINA 
  PALPALIS. 
  

  

  451 
  

  

  quick 
  fall 
  in 
  the 
  number 
  of 
  young 
  produced.* 
  If 
  such 
  decrease 
  in 
  rate 
  of 
  reproduction 
  

   had 
  taken 
  place 
  within 
  the 
  period 
  of 
  3 
  to 
  4 
  weeks 
  required 
  for 
  the 
  pupal 
  stages, 
  the 
  

   fact 
  would 
  be 
  disclosed 
  by 
  examination 
  of 
  the 
  puparia, 
  and 
  the 
  proportionate 
  

   numbers 
  of 
  them 
  found 
  in 
  early 
  and 
  late 
  stages 
  of 
  development. 
  At 
  a 
  certain 
  late 
  

   stage 
  in 
  development 
  the 
  pupa 
  is 
  found 
  within 
  the 
  puparium 
  shell 
  showing 
  traces 
  

   of 
  adult 
  coloration. 
  Such 
  pupae 
  must 
  have 
  been 
  from 
  larvae 
  deposited 
  at 
  least 
  

   two 
  weeks 
  before. 
  In 
  freshly 
  formed 
  puparia 
  the 
  pupa 
  is 
  unrecognisable, 
  and 
  it 
  

   requires 
  at 
  least 
  two 
  weeks 
  for 
  it 
  to 
  form 
  and 
  to 
  acquire 
  colour, 
  except 
  in 
  the 
  eyes, 
  

   which 
  are 
  coloured 
  almost 
  as 
  soon 
  as 
  it 
  takes 
  recognisable 
  form. 
  A 
  count 
  of 
  late 
  

   and 
  early 
  stages 
  of 
  puparia 
  collected 
  at 
  various 
  points 
  on 
  Kimmi 
  Island 
  was 
  therefore 
  

   made, 
  and 
  as 
  a 
  check 
  upon 
  it 
  some 
  3,000 
  puparia 
  collected 
  in 
  various 
  other 
  localities 
  

   were 
  examined 
  and 
  counted 
  to 
  ascertain 
  the 
  normal 
  proportions. 
  

  

  The 
  normal, 
  as 
  indicated 
  by 
  the 
  check, 
  was 
  27 
  '3 
  per 
  cent, 
  late 
  stages, 
  but 
  on 
  

   Kimmi 
  Island 
  the 
  late 
  stages 
  composed 
  46*3 
  per 
  cent, 
  of 
  the 
  total 
  found 
  and 
  examined. 
  

   There 
  should 
  have 
  been 
  — 
  if 
  the 
  normal 
  is 
  correctly 
  calculated 
  — 
  very 
  close 
  to 
  16 
  

   early 
  stage 
  to 
  6 
  late 
  stage 
  puparia 
  ; 
  actually 
  there 
  were 
  only 
  7 
  early 
  to 
  6 
  late, 
  indicating 
  

   that 
  less 
  than 
  half 
  as 
  many 
  young 
  were 
  being 
  produced 
  at 
  the 
  time 
  the 
  collection 
  

   was 
  made 
  as 
  were 
  being 
  produced 
  two 
  to 
  three 
  weeks 
  before. 
  

  

  In 
  March 
  the 
  island 
  was 
  revisited, 
  the 
  infestations 
  measured, 
  and 
  a 
  second 
  search 
  

   made 
  for 
  puparia. 
  Conditions 
  were 
  changed 
  notably. 
  Density 
  was 
  somewhat 
  

   lower 
  than 
  in 
  January, 
  but 
  food 
  had 
  become 
  more 
  plentiful, 
  female 
  percentage 
  

   had 
  dropped 
  to 
  a 
  figure 
  not 
  far 
  above 
  the 
  ordinary, 
  and 
  the 
  flies 
  were 
  no 
  longer 
  

   ravenous 
  or 
  especially 
  troublesome. 
  The 
  examination 
  of 
  puparia 
  disclosed 
  only 
  

  

  Table 
  XXXVIII. 
  

  

  Showing 
  Variation 
  in 
  Rate 
  of 
  Reproduction 
  (Number 
  of 
  Young 
  produced) 
  of 
  

   Glossina 
  palpalis 
  as 
  reflected 
  by 
  Proportion 
  of 
  Late 
  and 
  Early 
  Stages 
  of 
  Puparia. 
  

  

  Analysis 
  of 
  finds 
  of 
  puparia. 
  

  

  Kimmi 
  

   Island. 
  

  

  January 
  

   1914. 
  

  

  Total 
  and 
  

  

  averages 
  from 
  

  

  numerous 
  

  

  localities 
  ( 
  1 
  ) 
  

  

  (showing 
  

  

  normal) 
  . 
  

  

  Kimmi 
  

   Island. 
  

  

  March 
  

   1914. 
  

  

  No. 
  of 
  puparia 
  found 
  . 
  . 
  

   No. 
  of 
  early 
  stages 
  

   No. 
  of 
  late 
  stages 
  

   Percentage 
  of 
  late 
  stages 
  

  

  188 
  

   101 
  

   87 
  

   46-3 
  % 
  

  

  3615 
  

   2626 
  

   989 
  

   27-3% 
  (2) 
  

  

  155 
  

   130 
  

   25 
  

   16-1 
  % 
  

  

  Ratio 
  of 
  late 
  to 
  early 
  

  

  Excess 
  or 
  deficit, 
  early 
  stages 
  . 
  

  

  1 
  : 
  1-16 
  

  

  — 
  56 
  % 
  

  

  1 
  : 
  2-66 
  (2) 
  

   

  

  1 
  : 
  5-20 
  

  

  + 
  95 
  % 
  

  

  (1) 
  See 
  Sect. 
  VII 
  (a), 
  Table 
  XXVII. 
  

  

  (2) 
  This 
  ratio 
  would 
  be 
  a 
  constant 
  if 
  the 
  rate 
  of 
  reproduction 
  of 
  the 
  species 
  (number 
  

   of 
  young 
  deposited) 
  did 
  not 
  vary. 
  

  

  * 
  The 
  females 
  nourish 
  the 
  young 
  larva 
  until 
  it 
  is 
  full 
  fed 
  and 
  ready 
  to 
  transform 
  into 
  

   the 
  pupa, 
  equal 
  in 
  size 
  to 
  herself. 
  Normally 
  she 
  must 
  feed 
  (engorge) 
  at 
  least 
  3, 
  probably 
  

   4 
  and 
  possibly 
  5 
  times 
  in 
  order 
  to 
  provide 
  sufficient 
  food 
  for 
  a 
  single 
  larva. 
  

  

  