﻿INVESTIGATIONS 
  INTO 
  THE 
  BIONOMICS 
  OF 
  GLOSSINA 
  PALPALIS. 
  441 
  

  

  such 
  localities 
  as 
  breeding 
  places 
  it 
  is 
  probable 
  that 
  their 
  young 
  would 
  not 
  penetrate 
  

   deeply 
  enough 
  to 
  escape 
  these 
  wandering 
  ants, 
  but 
  the 
  flies 
  appear 
  never 
  to 
  deposit 
  

   their 
  young 
  in 
  such 
  places. 
  

  

  It 
  is 
  with 
  ants 
  as 
  with 
  so 
  many 
  other 
  potential 
  destructors, 
  including 
  monkeys 
  

   and 
  spiders. 
  If 
  flies 
  fed 
  or 
  attempted 
  to 
  feed 
  on 
  monkeys 
  they 
  would 
  be 
  destroyed 
  ; 
  

   if 
  they 
  flew 
  headlong 
  into 
  the 
  webs 
  of 
  spiders 
  their 
  species 
  would 
  probably 
  be 
  

   exterminated 
  on 
  the 
  spider 
  islands 
  ; 
  if 
  they 
  failed 
  to 
  display 
  characteristic 
  prescience 
  

   in 
  the 
  selection 
  of 
  breeding 
  places, 
  their 
  young 
  would 
  be 
  destroyed 
  by 
  ants, 
  parasites, 
  

   etc. 
  ; 
  but 
  in 
  each 
  case 
  their 
  instincts 
  save 
  them 
  from 
  destruction. 
  

  

  (2). 
  Hymenopterous 
  Parasites. 
  

  

  The 
  parasitism 
  of 
  puparia 
  of 
  Glossina 
  palpalis 
  in 
  good 
  breeding 
  grounds 
  by 
  Hymen- 
  

   optera 
  was 
  found 
  to 
  be 
  absolutely 
  negligible. 
  The 
  only 
  instance 
  encountered 
  was 
  

   on 
  Wema 
  Island, 
  where 
  in 
  a 
  catch 
  of 
  203 
  puparia, 
  3 
  were 
  found 
  attacked 
  by 
  a 
  small 
  

   gregarious 
  Chalcidid. 
  A 
  percentage 
  of 
  parasitism 
  at 
  this 
  point 
  of 
  1*5 
  was 
  thus 
  

   indicated. 
  At 
  other 
  points 
  near 
  at 
  hand 
  enough 
  more 
  unbroken 
  puparia 
  were 
  collected 
  

   and 
  examined 
  to 
  make 
  a 
  total 
  of 
  1,775, 
  and 
  not 
  another 
  parasitic 
  specimen 
  was 
  found. 
  

   From 
  other 
  points, 
  first 
  and 
  last, 
  more 
  than 
  3,000 
  living 
  puparia 
  were 
  collected 
  and 
  

   examined, 
  making 
  some 
  5,000 
  in 
  all, 
  and 
  no 
  other 
  case 
  of 
  parasitism 
  was 
  encountered. 
  

  

  Occasionally 
  empty 
  shells 
  are 
  found 
  with 
  small 
  round 
  holes 
  such 
  as 
  are 
  left 
  by 
  

   Hymenopterous 
  parasites 
  in 
  emerging, 
  but 
  except 
  at 
  the 
  one 
  point 
  noted 
  above, 
  

   examination 
  of 
  such 
  shells 
  has 
  never 
  disclosed 
  the 
  characteristic 
  (and 
  unmistakable) 
  

   exuviae 
  of 
  such 
  parasites. 
  The 
  selected 
  breeding 
  grounds 
  of 
  the 
  species 
  are 
  practically 
  

   absolute 
  protection 
  against 
  this 
  class 
  of 
  destructors. 
  

  

  The 
  parasite 
  discovered 
  on 
  Wema 
  bred 
  with 
  the 
  greatest 
  freedom 
  on 
  puparia 
  of 
  

   Glossina 
  in 
  confinement. 
  About 
  one 
  month 
  was 
  required 
  for 
  the 
  generation. 
  It 
  

   could 
  be 
  an 
  enemy 
  if 
  it 
  would, 
  but 
  its 
  instincts 
  lead 
  it 
  elsewhere 
  than 
  in 
  the 
  breeding 
  

   places 
  of 
  Glossina 
  in 
  search 
  of 
  prey. 
  

  

  (3). 
  Miscellaneous 
  Predatory 
  Destructors. 
  

  

  Ground 
  beetles 
  and 
  their 
  larvae 
  of 
  several 
  species, 
  Carabids 
  and 
  Elaterids, 
  are 
  

   known 
  to 
  be 
  destructive 
  to 
  puparia, 
  and 
  believed 
  to 
  be 
  very 
  destructive 
  to 
  them 
  

   except 
  in 
  the 
  dry 
  deposits 
  of 
  sand, 
  gravel 
  and 
  fine 
  vegetable 
  debris 
  normally 
  chosen 
  

   by 
  the 
  female 
  flies. 
  These, 
  or 
  other 
  destructors 
  unknown, 
  frequently 
  destroy 
  

   appreciable 
  proportions 
  of 
  puparia, 
  varying 
  in 
  different 
  localities. 
  It 
  was 
  thought 
  

   probable 
  that 
  counts 
  of 
  " 
  eaten 
  " 
  and 
  " 
  hatched 
  " 
  shells 
  found 
  at 
  breeding 
  grounds 
  

   in 
  sand 
  and 
  gravel 
  would 
  show 
  a 
  much 
  lower 
  proportion 
  of 
  " 
  eaten 
  " 
  than 
  at 
  breeding 
  

   grounds 
  in 
  vegetable 
  debris. 
  The 
  actual 
  counts, 
  however, 
  showed 
  no 
  great 
  difference 
  

   and 
  indicated 
  that 
  the 
  degree 
  of 
  protection 
  provided 
  by 
  vegetable 
  debris 
  is 
  almost 
  

   equal 
  to 
  that 
  provided 
  by 
  beach 
  sand 
  and 
  gravel 
  (Table 
  XXXVII). 
  There 
  is 
  a 
  much 
  

   greater 
  difference 
  between 
  good 
  and 
  poor 
  breeding 
  places 
  in 
  sand 
  and 
  gravel 
  or 
  

   in 
  vegetable 
  debris 
  than 
  between 
  sand 
  or 
  gravel 
  as 
  compared 
  with 
  vegetable 
  debris. 
  

  

  The 
  two 
  instances 
  on 
  Mbugwe 
  and 
  Nsadzi 
  Islands 
  where 
  destruction 
  by 
  predators 
  

   amounted 
  to 
  27*2 
  per 
  cent, 
  and 
  31*2 
  per 
  cent., 
  respectively, 
  are 
  worthy 
  of 
  special 
  

   mention. 
  In 
  each 
  case 
  the 
  prescience 
  of 
  the 
  female 
  was 
  deceived 
  by 
  superficial 
  

   conditions. 
  Both 
  cases 
  were 
  in 
  basking 
  spots 
  of 
  Varanus. 
  That 
  on 
  Nsadzi 
  Island 
  

  

  