﻿24 
  ROBERT 
  VEITCH. 
  

  

  The 
  newly 
  formed 
  pupa 
  is 
  cream-coloured, 
  but 
  as 
  the 
  pupal 
  stage 
  advances 
  the 
  

   the 
  darker 
  markings 
  of 
  the 
  future 
  beetle 
  appear 
  and 
  eventually 
  show 
  up 
  distinctly. 
  

   The 
  pupa 
  is 
  half 
  an 
  inch 
  in 
  length 
  and 
  the 
  pupal 
  stage 
  lasts 
  for 
  about 
  two 
  weeks. 
  

   The 
  newly 
  formed 
  beetle 
  rests 
  in 
  the 
  cocoon 
  for 
  a 
  considerable 
  number 
  of 
  days 
  before 
  

   venturing 
  forth 
  to 
  feed 
  and 
  mate, 
  and 
  when 
  it 
  does 
  so, 
  it 
  leaves 
  the 
  cane 
  by 
  the 
  hole 
  

   made 
  by 
  the 
  grub 
  prior 
  to 
  pupation. 
  The 
  period 
  that 
  elapses 
  between 
  the 
  laying 
  of 
  

   the 
  egg 
  and 
  the 
  emergence 
  of 
  the 
  fully 
  hardened 
  beetle 
  is 
  between 
  three 
  and 
  four 
  

   months. 
  The 
  beetle 
  is 
  half 
  an 
  inch 
  in 
  length 
  and 
  is 
  a 
  typical 
  Curculionid 
  ; 
  the 
  colour 
  

   is 
  dark 
  brown, 
  broken 
  by 
  several 
  black 
  patches 
  on 
  the 
  thorax 
  and 
  elytra. 
  The 
  sexes 
  

   can 
  be 
  distinguished 
  by 
  the 
  fact 
  that 
  in 
  the 
  male 
  the 
  rostum 
  is 
  shorter, 
  straighter, 
  

   thicker 
  and 
  also 
  rougher 
  on 
  the 
  under 
  surface 
  than 
  in 
  the 
  female 
  (fig. 
  1). 
  

  

  The 
  damage 
  caused 
  by 
  this 
  pest 
  is 
  often 
  very 
  severe, 
  for 
  it 
  is 
  no 
  uncommon 
  occur- 
  

   rence 
  to 
  harvest 
  fields 
  in 
  which 
  it 
  is 
  difficult 
  to 
  find 
  a 
  single 
  stalk 
  unattacked 
  by 
  it. 
  

   The 
  percentage 
  of 
  stalks 
  damaged 
  by 
  borers 
  at 
  the 
  Fiji 
  Mills 
  during 
  the 
  1917 
  crushing 
  

   season 
  was 
  14, 
  a 
  figure 
  that 
  is 
  sufficiently 
  high 
  to 
  cause 
  considerable 
  anxiety. 
  The 
  

   activities 
  of 
  this 
  pest 
  lead 
  to 
  a 
  very 
  considerable 
  reduction 
  in 
  the 
  crop, 
  for 
  the 
  sugar 
  

   yield 
  is 
  affected 
  in 
  several 
  ways. 
  In 
  the 
  first 
  place, 
  there 
  is 
  the 
  loss 
  of 
  sugar 
  in 
  the 
  

   cane 
  tissue 
  swallowed 
  or 
  chewed 
  by 
  the 
  borer 
  grubs, 
  and 
  in 
  badly 
  attacked 
  fields 
  

   this 
  is 
  very 
  considerable, 
  because 
  many 
  of 
  the 
  stalks 
  are 
  so 
  extensively 
  tunnelled 
  

   that 
  they 
  contain 
  little 
  or 
  no 
  sound 
  cane. 
  The 
  loss 
  of 
  sugar 
  is 
  not 
  confined 
  to 
  

   the 
  tissue 
  actually 
  eaten, 
  for 
  it 
  has 
  been 
  shown 
  that 
  the 
  boring 
  of 
  the 
  grubs 
  

   materially 
  reduces 
  the 
  sugar 
  content 
  of 
  the 
  untunnelled 
  portions 
  of 
  infested 
  

   stalks. 
  Another 
  source 
  of 
  loss 
  in 
  attacked 
  fields 
  is 
  the 
  increased 
  liability 
  

   of 
  bored 
  stalks 
  of 
  cane 
  to 
  break 
  and 
  fall 
  to 
  the 
  ground, 
  where 
  they 
  become 
  still 
  further 
  

   infested 
  and 
  rot 
  rapidly. 
  The 
  general 
  effect 
  of 
  the 
  attacks 
  of 
  this 
  pest 
  is 
  to 
  depreciate 
  

   the 
  value 
  of 
  a 
  large 
  proportion 
  of 
  the 
  crop 
  on 
  the 
  richer 
  lands, 
  and 
  to 
  render 
  much 
  

   of 
  it 
  absolutely 
  valueless 
  for 
  milling 
  purposes. 
  

  

  The 
  following 
  control 
  measures 
  have 
  been 
  found 
  to 
  be 
  of 
  great 
  assistance 
  in 
  Fiji 
  : 
  — 
  

  

  (1) 
  Seed 
  cane 
  for 
  replanting 
  fallow 
  fields 
  should 
  be 
  cut 
  in 
  areas 
  known 
  to 
  be 
  free 
  

   from 
  borer 
  ; 
  where 
  this 
  is 
  not 
  possible 
  the 
  seed 
  used 
  should 
  be 
  carefully 
  inspected, 
  

   and 
  all 
  infested 
  stalks 
  should 
  be 
  rejected 
  and 
  destroyed. 
  

  

  (2) 
  The 
  trash 
  on 
  badly 
  infested 
  fields 
  should 
  be 
  burned 
  as 
  soon 
  as 
  possible 
  after 
  

   cutting, 
  as 
  by 
  so 
  doing 
  numbers 
  of 
  beetles 
  underneath 
  the 
  trash 
  and 
  most 
  of 
  the 
  eggs, 
  

   grubs, 
  pupae 
  and 
  beetles 
  in 
  the 
  discarded 
  cane 
  will 
  be 
  destroyed. 
  Cane 
  stalks 
  that 
  

   are 
  badly 
  diseased 
  or 
  badly 
  attacked 
  by 
  the 
  borer 
  are 
  generally 
  left 
  on 
  the 
  field, 
  

   and 
  unless 
  the 
  trash 
  is 
  burned 
  off 
  it 
  finds 
  an 
  excellent 
  breeding 
  ground 
  in 
  such 
  

   discarded 
  cane. 
  Trash 
  should 
  not 
  be 
  burned 
  on 
  poor 
  land, 
  because 
  on 
  such 
  soils 
  it 
  

   is 
  necessary 
  to 
  preserve 
  all 
  humus-forming 
  material 
  ; 
  fortunately, 
  however, 
  cane 
  on 
  

   poor 
  land 
  is 
  seldom 
  badly 
  infested 
  by 
  the 
  weevil, 
  and 
  so 
  there 
  is 
  rarely 
  any 
  necessity 
  

   for 
  burning 
  trash 
  on 
  such 
  soils. 
  

  

  (3) 
  Fields 
  to 
  be 
  replanted 
  should 
  be 
  ploughed 
  out 
  as 
  soon 
  as 
  possible 
  after 
  

   harvesting 
  thus 
  depriving 
  the 
  pest 
  of 
  such 
  an 
  excellent 
  breeding 
  ground 
  as 
  neglected 
  

   volunteer 
  ratoons. 
  

  

  (4) 
  The 
  beetles 
  should 
  be 
  collected 
  by 
  means 
  of 
  traps 
  of 
  split 
  canes 
  laid 
  in 
  suitable 
  

   fields. 
  These 
  traps 
  attract 
  large 
  numbers 
  of 
  weevils 
  which 
  can 
  be 
  collected 
  and 
  

   destroyed. 
  

  

  