﻿INVESTIGATIONS 
  INTO 
  THE 
  BIONOMICS 
  OF 
  GLOSSINA 
  PALPALIS. 
  

  

  429 
  

  

  that 
  the 
  fly 
  population 
  was 
  not 
  permanently 
  resident, 
  but 
  was 
  continually 
  moving, 
  

   and 
  that 
  virtually 
  all 
  flies 
  infesting 
  it 
  at 
  a 
  given 
  time 
  were 
  likely 
  to 
  move 
  away 
  

   from 
  it 
  in 
  the 
  course 
  of 
  a 
  day 
  or 
  two, 
  to 
  be 
  replaced 
  by 
  others. 
  On 
  Kizima 
  the 
  

   flies 
  have 
  not 
  this 
  privilege. 
  They 
  must 
  remain 
  on 
  the 
  islet 
  and 
  put 
  up 
  with 
  whatever 
  

   shelter 
  it 
  affords, 
  or 
  leave 
  it 
  permanently. 
  If 
  Kizima 
  were 
  a 
  peninsula 
  of 
  Bulago, 
  

   like 
  Crocodile 
  Point, 
  its 
  light 
  shelter 
  and 
  breeding 
  grounds, 
  and 
  the 
  great 
  quantity 
  

   of 
  food 
  it 
  provides, 
  would 
  certainly 
  attract 
  to 
  it 
  even 
  more 
  flies 
  than 
  infest 
  Crocodile 
  

   Point 
  ; 
  but 
  it 
  must 
  be 
  concluded 
  that 
  its 
  heavy 
  infestations 
  under 
  such 
  hypothetical 
  

   conditions, 
  like 
  the 
  heavy 
  infestation 
  actually 
  existing 
  on 
  Crocodile 
  Point, 
  would 
  

   be, 
  as 
  the 
  other 
  certainly 
  is, 
  due 
  to 
  the 
  existence 
  of 
  good 
  massive 
  shelter 
  within 
  

   range 
  or 
  reach 
  of 
  the 
  flies 
  infesting 
  it. 
  

  

  These 
  same 
  facts 
  concerning 
  the 
  movements 
  of 
  flies 
  along 
  shore, 
  or 
  along 
  other 
  

   favourite 
  courses, 
  answer 
  also 
  the 
  first 
  objections 
  made 
  above. 
  The 
  active 
  flies 
  

   are 
  active 
  with 
  some 
  positive 
  object 
  ; 
  the 
  females 
  are 
  seeking 
  either 
  food 
  or 
  breeding 
  

   places 
  ; 
  the 
  males 
  are 
  seeking 
  either 
  food 
  or 
  association 
  with 
  the 
  females. 
  Light 
  

   shelter 
  provides 
  the 
  best 
  shade 
  for 
  breeding 
  places, 
  and 
  food 
  (Varanus 
  and 
  crocodile 
  

   especially) 
  is 
  most 
  frequently 
  encountered 
  associated 
  with 
  it 
  ; 
  therefore 
  it 
  is 
  sought 
  

   by 
  the 
  females 
  and 
  equally 
  by 
  the 
  males 
  during 
  their 
  hours 
  of 
  activity. 
  At 
  other 
  

   times 
  (during 
  the 
  night, 
  storms 
  and 
  dull 
  weather 
  generally), 
  both 
  sexes 
  remain 
  

   in 
  seclusion, 
  and 
  it 
  is 
  then 
  that 
  massive 
  shelter 
  is 
  presumptively 
  necessary 
  for 
  their 
  

   protection. 
  

  

  A 
  large 
  number 
  of 
  data 
  collected 
  during 
  the 
  course 
  of 
  the 
  survey 
  of 
  small 
  islands 
  

   sustained 
  this 
  as 
  the 
  true 
  explanation 
  for 
  lightness 
  or 
  absence 
  of 
  infestation 
  on 
  a 
  

   fair 
  number 
  of 
  them. 
  The 
  data 
  are 
  of 
  a 
  sort 
  not 
  easily 
  presented, 
  and 
  Table 
  XXXIII 
  

   is 
  suggestive 
  without 
  being 
  conclusive. 
  Eeliance 
  in 
  drawing 
  conclusions 
  was 
  

   principally 
  placed 
  in 
  such 
  comparative 
  studies 
  as 
  between 
  infestations 
  at 
  points 
  

   such 
  as 
  are 
  illustrated 
  in 
  the 
  sketches 
  accompanying 
  (fig. 
  8). 
  

  

  Bubembe 
  

  

  Crocodile 
  

   Point" 
  ^ 
  

  

  Grassland! 
  

  

  Island 
  

  

  ^ 
  

  

  

  ^* 
  ,A 
  ©^! 
  

  

  \b\zt 
  

  

  'w&zm* 
  

  

  Massive 
  She 
  iter 
  ■_£< 
  

  

  Light 
  Shelter 
  & 
  ,,,_„, 
  

   breeding 
  ground. 
  _ 
  kiMi-l 
  

  

  Fig. 
  8. 
  Illustrating 
  the 
  correlation 
  between 
  character 
  of 
  shelter 
  and 
  infestation 
  of 
  small 
  

  

  islands 
  by 
  Glossina. 
  

  

  In 
  each 
  of 
  the 
  three 
  cases 
  we 
  have 
  an 
  area 
  of 
  light 
  shelter 
  with 
  good 
  to 
  very 
  

   good 
  breeding 
  grounds 
  located 
  in 
  certain 
  relations 
  to 
  massive 
  shelter. 
  These 
  three 
  

   localities 
  are 
  roughly 
  equal 
  in 
  gross 
  area 
  and 
  attractiveness 
  to 
  fly 
  ; 
  the 
  two 
  islets 
  

   being 
  rather 
  superior 
  to 
  the 
  peninsula 
  than 
  otherwise. 
  

   (659) 
  f2 
  

  

  