﻿NOTES 
  ON 
  THE 
  COCONUT 
  BEETLE 
  IN 
  KENYA 
  COLONY. 
  105 
  

  

  Combining 
  the 
  times 
  for 
  the 
  three 
  immature 
  stages 
  of 
  the 
  life-history 
  the 
  data 
  

   so 
  far 
  obtained 
  point 
  to 
  a 
  period 
  of 
  about 
  four 
  and 
  a 
  half 
  months 
  between 
  the 
  

   deposition 
  of 
  the 
  egg 
  and 
  the 
  emergence 
  of 
  the 
  beetle. 
  Sometimes, 
  doubtless, 
  the 
  

   period 
  is 
  a 
  little 
  shorter 
  than 
  this, 
  and 
  more 
  data 
  may 
  well 
  show 
  that 
  it 
  is 
  often 
  

   appreciably 
  longer. 
  Some 
  observations 
  were 
  made 
  as 
  to 
  how 
  quickty 
  a 
  coconut 
  

   log 
  could 
  become 
  suitable 
  for 
  food 
  for 
  the 
  grubs. 
  On 
  10th 
  March 
  a 
  number 
  of 
  logs 
  

   about 
  three 
  feet 
  long 
  were 
  seen 
  to 
  be 
  thoroughly 
  hard 
  and 
  unfit 
  for 
  food 
  for 
  beetle 
  

   grubs. 
  The 
  weather 
  was 
  then 
  very 
  hot 
  and 
  dry, 
  but 
  the 
  Long 
  Rains 
  began 
  shortlv 
  

   afterwards 
  and 
  April 
  was 
  a 
  very 
  wet 
  month. 
  On 
  2nd 
  August 
  they 
  were 
  examined 
  

   again 
  and 
  found 
  to 
  be 
  thoroughly 
  rotten, 
  and 
  a 
  number 
  of 
  beetle 
  grubs, 
  including 
  

   some 
  in 
  the 
  last 
  instar, 
  were 
  taken. 
  The 
  condition 
  of 
  the 
  logs 
  was 
  just 
  as 
  if 
  the 
  grubs 
  

   had 
  been 
  feeding 
  there 
  all 
  their 
  lives. 
  At 
  any 
  rate 
  coconut 
  logs 
  may 
  quickly 
  become 
  

   breeding-grounds 
  for 
  the 
  beetle. 
  

  

  Records 
  of 
  Numbers 
  of 
  Beetles 
  captured 
  on 
  European 
  Plantations. 
  

  

  Information 
  about 
  the 
  numbers 
  of 
  beetles 
  collected 
  by 
  hand 
  on 
  three 
  European 
  

   coconut 
  plantations 
  on 
  a 
  known 
  area 
  and 
  in 
  a 
  known 
  time 
  was 
  kindly 
  supplied 
  by 
  

   gentlemen 
  owning 
  or 
  managing 
  them. 
  Collecting 
  the 
  beetles 
  and 
  not 
  permitting 
  

   breeding-places 
  on 
  the 
  plantations 
  are 
  the 
  usual 
  methods 
  of 
  defence 
  against 
  the 
  beetle. 
  

  

  Mr. 
  A. 
  S. 
  Kerr 
  placed 
  at 
  my 
  disposal 
  the 
  records 
  of 
  collecting 
  in 
  three 
  plantations 
  

   on 
  an 
  estate 
  on 
  the 
  coast 
  at 
  Gazi, 
  30 
  miles 
  south 
  of 
  Mombasa. 
  These 
  plantations 
  

   total 
  about 
  1,250 
  acres, 
  and 
  allowing 
  for 
  gaps 
  would 
  contain 
  something 
  like 
  50,000 
  

   trees. 
  At 
  the 
  end 
  of 
  1920 
  the 
  trees 
  varied 
  in 
  age 
  from 
  just 
  planted 
  up 
  to 
  about 
  six 
  

   years, 
  with 
  just 
  a 
  few 
  older 
  trees. 
  There 
  were 
  only 
  a 
  very 
  few 
  native-owned 
  coconut 
  

   trees 
  near 
  to 
  the 
  plantations. 
  Collecting 
  had 
  been 
  done 
  before 
  1918, 
  but 
  the 
  earlier 
  

   records 
  were 
  not 
  available. 
  For 
  the 
  last 
  three 
  years 
  the 
  figures 
  had 
  been 
  : 
  — 
  

  

  1918 
  7.100 
  beetles. 
  

  

  1919 
  5,340 
  „ 
  

  

  1920 
  632 
  „ 
  

  

  Total 
  .. 
  .. 
  13,072 
  ,, 
  

  

  In 
  1918 
  and 
  1919 
  a 
  boy's 
  task 
  was 
  ten 
  beetles 
  a 
  day. 
  In 
  1920 
  it 
  was 
  not 
  necessary 
  

   to 
  do 
  much 
  collecting 
  and 
  in 
  October 
  the 
  beetles 
  were 
  so 
  scarce 
  that 
  only 
  two 
  were 
  

   required 
  to 
  be 
  brought 
  in 
  for 
  a 
  day's 
  work. 
  

  

  Mr. 
  W. 
  E. 
  F. 
  de 
  Lacy 
  gave 
  me 
  the 
  figures 
  for 
  the 
  whole 
  of 
  1919 
  for 
  a 
  plantation 
  

   at 
  Changamwe, 
  about 
  four 
  miles 
  from 
  Mombasa, 
  on 
  the 
  mainland. 
  The 
  plantation 
  

   contained 
  2,096 
  coconut 
  trees, 
  which, 
  at 
  55 
  trees 
  to 
  the 
  acre, 
  would 
  be 
  equivalent 
  

   to 
  an 
  area 
  of 
  38 
  acres. 
  It 
  was 
  adjacent 
  to 
  one 
  excellently 
  managed 
  plantation, 
  

   but 
  was 
  near 
  to 
  native-owned 
  coconuts 
  among 
  which 
  conditions 
  were 
  extremely 
  

   favourable 
  to 
  the 
  beetle. 
  Mr. 
  de 
  Lacy 
  had 
  eliminated 
  the 
  breeding-places 
  of 
  the 
  

   beetle 
  from 
  his 
  plantation 
  and 
  believed 
  that 
  all 
  the 
  beetles 
  captured 
  there 
  had 
  been 
  

   bred 
  elsewhere. 
  Boys 
  were 
  paid 
  about 
  a 
  penny 
  a 
  beetle 
  for 
  each 
  one 
  brought 
  in. 
  

   The 
  number 
  captured 
  during 
  the 
  year 
  was 
  1 
  ,009. 
  

  

  Mr. 
  James 
  Paton 
  supplied 
  figures 
  for 
  the 
  months 
  from 
  September 
  to 
  December 
  

   1920, 
  for 
  a 
  young 
  plantation 
  of 
  about 
  400 
  acres 
  situated 
  on 
  the 
  mainland 
  about 
  

   six 
  miles 
  from 
  Mombasa, 
  where 
  he 
  employs 
  two 
  boys 
  for 
  collecting 
  beetles. 
  The 
  

   plantation 
  is 
  kept 
  free 
  from 
  breeding-places. 
  There 
  are 
  a 
  few 
  small 
  native 
  plantations 
  

   near, 
  but 
  much 
  of 
  the 
  adjacent 
  -area 
  is 
  mangrove 
  swamp 
  or 
  other 
  wild 
  vegetation 
  

   where 
  it 
  is 
  unlikely 
  that 
  any 
  number 
  of 
  beetles 
  can 
  breed. 
  In 
  the 
  four 
  months 
  the 
  

   boys 
  collected 
  360 
  beetles. 
  

  

  It 
  will 
  be 
  seen 
  that 
  the 
  numbers 
  of 
  beetles 
  captured 
  per 
  acre 
  per 
  annum 
  are 
  at 
  

   the 
  rate 
  of 
  about 
  3 
  for 
  the 
  first 
  and 
  last 
  plantation 
  and 
  26 
  for 
  the 
  second 
  one. 
  

  

  