﻿428 
  

  

  W. 
  F. 
  FISKE. 
  

  

  breeding 
  grounds. 
  Food, 
  also, 
  was 
  especially 
  common 
  on 
  these 
  islets, 
  and 
  the 
  

   only 
  reason 
  which 
  could 
  be 
  assigned 
  for 
  absence 
  of 
  fly 
  was 
  the 
  total 
  lack 
  of 
  what 
  

   has 
  been 
  called 
  " 
  massive 
  shelter 
  ' 
  of 
  the 
  sort 
  provided 
  by 
  large 
  trees 
  in 
  masses, 
  

   or 
  very 
  heavy 
  masses 
  of 
  shrubbery 
  ; 
  in 
  short, 
  by 
  either 
  true 
  forest, 
  or 
  by 
  a 
  type 
  

   of 
  vegetation 
  approximating 
  true 
  forest. 
  

  

  If 
  this 
  were 
  the 
  true 
  explanation 
  it 
  would 
  serve 
  also 
  to 
  account 
  for 
  lightness 
  of 
  

   infestation 
  on 
  various 
  other 
  islands 
  — 
  notably 
  Lukalu 
  West 
  and 
  Kizima, 
  which 
  

   possess 
  relatively 
  to 
  such 
  islands 
  as 
  Tavu, 
  Kimmi, 
  and 
  nearly 
  all 
  of 
  those 
  of 
  larger 
  

   size, 
  but 
  little 
  massive 
  shelter. 
  

  

  Table 
  XXXIII. 
  

  

  Showing 
  Correlation 
  between 
  Character 
  of 
  Shelter 
  and 
  Infestation 
  of 
  Small 
  

  

  Islands 
  by 
  Glossina 
  palpalis. 
  

  

  

  

  character 
  of 
  

  

  breeding 
  

   ground. 
  

  

  | 
  

   * 
  Character 
  of 
  Shelter. 
  Infestation. 
  

  

  Island. 
  

  

  Light. 
  

  

  Massive. 
  

  

  Male 
  

   density. 
  

  

  1 
  

  

  Female 
  

   percentage 
  

  

  Tavu 
  

  

  Kimmi 
  . 
  . 
  

   Manene 
  . 
  . 
  

   Dwavannu 
  

   Ziro 
  

  

  Kerenge 
  . 
  . 
  

   Lukalu 
  West 
  

   Dyavadermi 
  

   Kawari 
  West 
  

   Kizima 
  . 
  . 
  

   Islet 
  S. 
  of 
  Dziru. 
  

   Lukalu 
  East 
  

   Kukassu 
  . 
  . 
  

  

  

  Very 
  good 
  . 
  

  

  Very 
  good 
  . 
  

  

  Good 
  

  

  Good 
  

  

  Good 
  

  

  Good 
  

  

  Very 
  good 
  . 
  

  

  Good 
  

  

  Good 
  

  

  Good 
  

  

  Very 
  good 
  . 
  

  

  Very 
  good 
  . 
  

  

  Very 
  good 
  . 
  

  

  Good 
  

  

  Very 
  good 
  . 
  

  

  Good 
  

  

  Good 
  

  

  Good 
  

  

  Good 
  

  

  Very 
  good 
  . 
  

  

  Good 
  

  

  Good 
  

  

  Good 
  

  

  Very 
  good 
  . 
  

  

  Very 
  good 
  . 
  

  

  Very 
  good 
  . 
  

  

  Very 
  good 
  . 
  

  

  Very 
  good 
  . 
  

  

  Very 
  good 
  . 
  

  

  Good 
  

  

  Good 
  

  

  Good 
  

  

  Poor 
  

  

  Poor 
  

  

  Poor 
  

  

  Poor 
  

  

  Very 
  poor. 
  . 
  

  

  None 
  

  

  None 
  

  

  46-6 
  

  

  24'3 
  

  

  17-7 
  

  

  23'0 
  

  

  5-4 
  

  

  3*8 
  

  

  9'7 
  

  

  8'0 
  

  

  7'8 
  

  

  2'5 
  

  

  3*8 
  

  

  Nil. 
  

  

  Nil. 
  

  

  17-1 
  

   57-5 
  

   12-4 
  

   9-8 
  

   23-7 
  

   24'7 
  

   28-5 
  

   21-4 
  

   12-5 
  

   11*0 
  

   266 
  

  

  Opposed 
  to 
  the 
  theory 
  that 
  massive 
  shelter 
  is 
  necessary 
  was 
  the 
  fact 
  that 
  the 
  

   active 
  flies 
  showed 
  a 
  strong 
  preference 
  for 
  such 
  light 
  shelter 
  as 
  is 
  provided 
  by 
  low 
  

   massed 
  shrubbery 
  with 
  open 
  spaces 
  between 
  thickets 
  or 
  clumps 
  of 
  it, 
  masses 
  or 
  

   clumps 
  of 
  rank-growing 
  herbs, 
  vine-covered 
  bushes, 
  or 
  stumps, 
  etc. 
  This 
  is 
  the 
  

   kind 
  of 
  shelter 
  that 
  provides 
  shade 
  for 
  the 
  most 
  attractive 
  breeding 
  places, 
  and 
  it 
  

   is 
  indubitably 
  most 
  attractive 
  to 
  the 
  active 
  flies 
  of 
  both 
  sexes. 
  

  

  Opposed 
  to 
  the 
  theory 
  also 
  was 
  the 
  fact 
  that 
  such 
  long, 
  narrow 
  sand-pits 
  as 
  

   Crocodile 
  Point 
  on 
  Bulago 
  Island, 
  which 
  are 
  devoid 
  of 
  massive 
  shelter 
  and 
  semi- 
  

   detached 
  from 
  the 
  main 
  body 
  of 
  the 
  island 
  (or 
  mainland), 
  are 
  apt 
  to 
  be 
  densely 
  

   infested 
  by 
  fly. 
  There 
  is 
  more 
  and 
  better 
  massive 
  shelter, 
  and 
  much 
  better 
  breeding 
  

   grounds, 
  on 
  the 
  island 
  of 
  Kizima, 
  for 
  example, 
  than 
  on 
  Crocodile 
  Point, 
  Bulago 
  ; 
  

   yet 
  the 
  infestatiomof 
  Kizima, 
  in 
  January 
  1914, 
  was 
  only 
  2*5 
  as 
  compared 
  with 
  22*7 
  

   at 
  Crocodile 
  Point. 
  

  

  This 
  last 
  objection 
  is 
  met, 
  however, 
  by 
  the 
  facts 
  disclosed 
  in 
  the 
  catching 
  experi- 
  

   ment 
  on 
  Crocodile 
  Point 
  cited 
  in 
  Sect. 
  Ill 
  (a), 
  which 
  proved 
  conclusively 
  enough 
  

  

  