﻿30 
  

  

  The 
  pupae 
  are 
  rarely 
  seen, 
  and 
  never 
  in 
  considerable 
  numbers 
  ; 
  many 
  

   of 
  the 
  larvae 
  probably 
  pupate 
  at 
  some 
  distance 
  below 
  the 
  surface 
  of 
  

   the 
  ground. 
  The 
  pupal 
  stage 
  lasts 
  for 
  about 
  10 
  days 
  to 
  a 
  fortnight. 
  

   In 
  Samoa 
  many 
  control 
  methods 
  have 
  been 
  tried. 
  In 
  the 
  author's 
  

   opinion, 
  tar 
  is 
  the 
  most 
  valuable 
  repellent, 
  but 
  its 
  use 
  gives 
  only 
  a 
  

   small 
  measure 
  of 
  protection. 
  Trees 
  treated 
  with 
  lysol, 
  or 
  lysol 
  mixed 
  

   with 
  tar, 
  continued 
  to 
  be 
  badly 
  injured. 
  Sand 
  was 
  poured 
  into 
  the 
  

   crowns 
  of 
  a 
  few 
  trees, 
  and 
  on 
  others 
  a 
  mixture 
  of 
  sand 
  and 
  arsenic, 
  

   care 
  being 
  taken 
  that 
  plenty 
  lodged 
  at 
  the 
  bases 
  of 
  all 
  the 
  leaves. 
  

   The 
  arsenic 
  injured 
  the 
  leaves 
  ; 
  otherwise 
  the 
  trees 
  were 
  not 
  badly 
  

   attacked, 
  but 
  there 
  was 
  not 
  sufficient 
  time 
  to 
  test 
  this 
  method 
  thor- 
  

   oughly. 
  Dusting 
  with 
  white 
  arsenic, 
  Paris 
  green, 
  etc., 
  is 
  not 
  satis- 
  

   factory, 
  owing 
  to 
  the 
  fact 
  that 
  the 
  beetles 
  do 
  not 
  swallow 
  the 
  leaves 
  

   or 
  fibre. 
  Pouring 
  carbon 
  bisulphide 
  into 
  the 
  holes 
  made 
  by 
  the 
  beetles, 
  

   killed 
  the 
  beetles, 
  but 
  also 
  injured 
  the 
  tree. 
  Bait 
  traps, 
  if 
  carefully 
  

   prepared, 
  are 
  quite 
  effective 
  on 
  well-cleaned 
  plantations, 
  but 
  they 
  

   are 
  expensive 
  and 
  require 
  close 
  supervision. 
  For 
  the 
  present, 
  the 
  

   most 
  effective 
  method 
  is 
  to 
  destroy 
  the 
  breeding 
  places 
  of 
  the 
  beetle 
  

   by 
  removing 
  all 
  decaying 
  logs, 
  etc., 
  from 
  the 
  plantation. 
  [See 
  

   above, 
  pp. 
  26-28.] 
  

  

  WoLcoTT 
  (G. 
  N.). 
  Report 
  on 
  a 
  Trip 
  to 
  Demerara, 
  Trinidad 
  and 
  

   Barbados 
  during 
  the 
  Winter 
  of 
  1913. 
  — 
  Jl. 
  Econ. 
  Entom., 
  Concord, 
  

   vi. 
  no. 
  6, 
  Dec. 
  1913, 
  pp. 
  443-457. 
  

  

  In 
  Demerara 
  the 
  small 
  moth-borer 
  {Diatraea 
  saccharalis, 
  F.), 
  and 
  

   the 
  closely 
  allied 
  species, 
  D. 
  lineolata, 
  Walk., 
  and 
  D. 
  canella, 
  Hmp., 
  

   are 
  the 
  most 
  serious 
  pests 
  of 
  cane. 
  On 
  nearly 
  every 
  estate 
  there 
  are 
  

   gangs 
  of 
  boys, 
  sometimes 
  as 
  many 
  as 
  50 
  in 
  a 
  gang, 
  who 
  do 
  nothing 
  

   else 
  the 
  year 
  round 
  but 
  cut 
  out 
  the 
  dead 
  hearts 
  killed 
  by 
  the 
  Diatraea 
  

   larvae. 
  It 
  shows 
  how 
  serious 
  the 
  pest 
  is 
  that 
  the 
  boys 
  have 
  no 
  diflGi- 
  

   culty 
  in 
  collecting 
  700 
  larvae 
  day 
  after 
  day. 
  The 
  problem 
  of 
  control- 
  

   ling 
  Diatraea 
  is 
  most 
  seriously 
  complicated 
  by 
  the 
  dry 
  and 
  wet 
  seasons. 
  

   There 
  are 
  always 
  two, 
  and 
  sometimes 
  four, 
  wet 
  seasons 
  and 
  as 
  many 
  

   dry. 
  Cane 
  is 
  cut 
  towards 
  the 
  end 
  of 
  each 
  dry 
  season, 
  and 
  seed 
  cane 
  

   is 
  planted 
  at 
  each 
  wet 
  season. 
  A 
  crop 
  takes 
  18 
  months 
  to 
  mature, 
  so 
  

   that 
  cane 
  in 
  all 
  stages 
  of 
  growth 
  is 
  present 
  on 
  a 
  single 
  estate 
  at 
  all 
  

   times. 
  Moths 
  will 
  fly 
  out 
  a 
  hundred 
  yards 
  or 
  more 
  from 
  the 
  older 
  

   cane 
  and 
  deposit 
  eggs 
  on 
  the 
  young 
  cane 
  from 
  which 
  all 
  the 
  dead 
  

   hearts 
  have 
  just 
  been 
  cut 
  out, 
  and 
  in 
  a 
  few 
  weeks 
  the 
  infestation 
  will 
  

   be 
  as 
  heavy 
  as 
  if 
  no 
  control 
  had 
  been 
  attempted. 
  In 
  Demerara 
  there 
  

   are 
  four 
  insect 
  parasites 
  of 
  Diatraea, 
  but 
  in 
  spite 
  of 
  these, 
  and 
  of 
  the 
  

   artificial 
  control, 
  Diatraea 
  still 
  remains 
  a 
  serious 
  pest. 
  The 
  one 
  measure 
  

   that 
  can 
  be 
  adopted 
  is 
  the 
  simultaneous 
  planting 
  of 
  enormous 
  blocks 
  

   of 
  cane 
  ; 
  it 
  is 
  the 
  indiscriminate 
  scattering 
  of 
  the 
  fields 
  of 
  all 
  ages 
  of 
  

   cane 
  on 
  an 
  estate 
  that 
  makes 
  possible 
  the 
  rapid 
  and 
  easy 
  infestation 
  

   of 
  young 
  cane. 
  

  

  The 
  only 
  other 
  serious 
  cane 
  pest 
  in 
  Demerara 
  is 
  the 
  giant 
  moth- 
  

   borer 
  (Castnia 
  licus, 
  F.). 
  The 
  larva 
  enters 
  the 
  cane 
  near 
  the 
  ground 
  

   and 
  burrows 
  down 
  into 
  the 
  root 
  and 
  up 
  into 
  the 
  stalk. 
  There 
  are 
  

   fortunately 
  several 
  practical 
  methods 
  of 
  control. 
  They 
  are 
  as 
  follows 
  : 
  

   (1) 
  Collecting 
  the 
  adult 
  moths 
  in 
  butterfly 
  nets 
  ; 
  (2) 
  cutting 
  out 
  the 
  

   young 
  larvae 
  in 
  the 
  young 
  ratoon 
  cane 
  ; 
  (3) 
  cutting 
  out 
  the 
  older 
  

  

  