﻿360 
  

  

  W. 
  F. 
  FISKE. 
  

  

  Table 
  VIII. 
  

  

  Extremes 
  of 
  Variations 
  in 
  Economic 
  Status 
  of 
  Glossina 
  palpalis 
  as 
  indicated 
  by 
  

  

  Female 
  Percentage. 
  

  

  Locality 
  and 
  

  

  Catch 
  of 
  My. 
  

  

  | 
  No. 
  of 
  

   "Boy 
  

   Hours." 
  

  

  Indicated 
  Density. 
  

  

  Female 
  

  

  Point. 
  

  

  Males. 
  

  

  Fe- 
  

   males. 
  

  

  Total. 
  

  

  Males. 
  

  

  Females 
  

  

  Total. 
  

  

  Ratio. 
  

  

  Bugaba 
  — 
  Pt. 
  15. 
  . 
  

   „ 
  16.. 
  

   ,. 
  17.. 
  

   Bale— 
  Pt. 
  49 
  

   „ 
  50 
  

   51 
  

  

  33 
  

   39 
  

   32 
  

   20 
  

   10 
  

   7 
  

  

  1 
  

   1 
  

  

  

  

  84 
  

   80 
  

   40 
  

  

  34 
  

  

  40 
  

   32 
  

   104 
  

   90 
  

   47 
  

  

  3 
  

   H 
  

  

  H 
  

  

  2 
  

  

  2 
  

   2 
  

  

  11 
  

   260 
  

   21-3 
  

   10-0 
  

   50 
  

   35 
  

  

  •3 
  

   •6 
  

  

  •o 
  

  

  42-0 
  

   400 
  

   20-0 
  

  

  113 
  

   266 
  

   21-3 
  

   520 
  

   45-0 
  

   23 
  5 
  

  

  3-0 
  % 
  

   2-5 
  % 
  

  

  *o% 
  

  

  80 
  8 
  % 
  

   88-8 
  % 
  

   86-1% 
  

  

  Totals 
  — 
  Bugaba. 
  . 
  

   Bale 
  

  

  104 
  

  

  37 
  

  

  2 
  

   204 
  

  

  106 
  

   241 
  

  

  6 
  

   6 
  

  

  17-3 
  

  

  6-2 
  

  

  •3 
  

   34-0 
  

  

  17 
  7 
  

   40-2 
  

  

  1-9 
  % 
  

  

  84-6 
  % 
  

  

  It 
  is 
  also 
  necessary 
  to 
  take 
  account 
  of 
  the 
  reason 
  for 
  the 
  excessive 
  activity 
  of 
  

   female 
  flies 
  at 
  Bale. 
  If 
  this 
  is 
  caused 
  by 
  scarcity 
  of 
  food, 
  it 
  appears 
  that 
  all 
  the 
  f 
  emales 
  y 
  

   and 
  obviously 
  the 
  males 
  as 
  well, 
  must 
  be 
  hunting 
  for 
  food. 
  Therefore 
  a 
  man 
  fishing 
  

   on 
  the 
  beach 
  would 
  be 
  likely 
  to 
  encounter 
  no 
  less 
  than 
  40 
  hungry 
  flies 
  per 
  hour. 
  

  

  But 
  at 
  Bugaba 
  there 
  would 
  be 
  only 
  one 
  hungry 
  female 
  each 
  three 
  hours, 
  and 
  if 
  the 
  

   males 
  are 
  proportionately 
  hungry, 
  not 
  more 
  than 
  two 
  flies 
  that 
  were 
  actively 
  seeking 
  

   food 
  would 
  be 
  encountered 
  each 
  three 
  hours 
  by 
  the 
  fisherman. 
  This 
  would 
  indicate 
  

   that 
  the 
  fisherman 
  on 
  Bale 
  beach 
  would 
  be 
  exposed 
  to 
  60 
  food-hunting 
  flies 
  to 
  1 
  for 
  

   the 
  fisherman 
  at 
  Bugaba 
  ; 
  i.e., 
  the 
  fly 
  at 
  Bale, 
  though 
  less 
  numerous 
  by 
  half, 
  is 
  

   indicated 
  to 
  be 
  60-fold 
  more 
  dangerous 
  to 
  a 
  population 
  living 
  in 
  contact 
  with 
  it 
  

   than 
  the 
  fly 
  at 
  Bugaba. 
  

  

  This 
  point 
  seemed 
  so 
  important 
  that 
  confirmation 
  of 
  conclusions 
  tentatively 
  

   deduced 
  by 
  the 
  above 
  method 
  was 
  sought 
  in 
  various 
  ways, 
  and 
  the 
  final 
  conclusions 
  

   are 
  that 
  the 
  fly 
  really 
  varies 
  in 
  economic 
  status 
  over 
  a 
  much 
  wider 
  range 
  than 
  as 
  

   above 
  indicated. 
  There 
  are 
  several 
  reasons 
  for 
  making 
  this 
  the 
  final 
  conclusion 
  

   which 
  need 
  not 
  be 
  gone 
  into 
  ; 
  the 
  point 
  upon 
  which 
  evidence 
  is 
  submitted 
  in 
  the 
  

   pages 
  immediately 
  following 
  is 
  that 
  of 
  the 
  much 
  greater 
  freedom 
  with 
  which 
  fly 
  

   attacks 
  man 
  when 
  the 
  female 
  percentage 
  (for 
  a 
  district 
  or 
  region) 
  is 
  high 
  than 
  when 
  

   it 
  is 
  low. 
  

  

  II 
  (£>). 
  Correlation 
  between 
  High 
  Percentage 
  of 
  Females, 
  artificially 
  produced, 
  

   and 
  Persistence 
  of 
  Attack 
  upon 
  Man. 
  

  

  In 
  the 
  course 
  of 
  the 
  Lugazi 
  experiment 
  to 
  which 
  reference 
  has 
  already 
  been 
  made 
  

   (p. 
  357), 
  two 
  adult 
  goats 
  and 
  one 
  — 
  subsequently 
  another 
  — 
  small 
  pig 
  (of 
  European 
  

   stock) 
  were 
  tethered, 
  equally 
  exposed 
  to 
  attack 
  by 
  Glossina, 
  along 
  the 
  shores 
  of 
  the 
  

   island. 
  From 
  the 
  15th 
  to 
  the 
  20th 
  of 
  December 
  great 
  care 
  was 
  taken 
  not 
  to 
  disturb 
  

   the 
  wild 
  hosts 
  of 
  the 
  fly 
  on 
  this 
  islet. 
  The 
  female 
  percentage 
  taken 
  on 
  the 
  19th 
  and 
  

   20th 
  was 
  found 
  to 
  be 
  15 
  "5, 
  which 
  was 
  probably 
  maintained 
  throughout 
  this 
  period.. 
  

  

  