﻿INSECTS 
  IN 
  SUGAE-CANE 
  PLANTATIONS 
  IN 
  FIJI. 
  

  

  23 
  

  

  are 
  grown, 
  and 
  as 
  the 
  borer 
  prefers 
  soft 
  sweet 
  stalks 
  of 
  cane 
  to 
  tnnnel 
  in, 
  it 
  almost 
  

   invariably 
  happens 
  that 
  on 
  similar 
  types 
  of 
  soil 
  Badila 
  suffers 
  much 
  more 
  severely 
  

   than 
  Malabar. 
  

  

  The 
  white 
  elongate 
  oval 
  egg 
  of 
  this 
  pest 
  is 
  about 
  one-sixteenth 
  of 
  an 
  inch 
  in 
  length, 
  

   and 
  is 
  laid 
  in 
  the 
  rind 
  of 
  the 
  stalk 
  behind 
  a 
  half-loosened 
  leaf-sheath, 
  and 
  a 
  week 
  

   after 
  oviposition 
  the 
  grub 
  hatches 
  out 
  and 
  bores 
  into 
  the 
  cane, 
  becoming 
  full-grown 
  

   in 
  eight 
  to 
  eleven 
  weeks. 
  In 
  boring 
  the 
  cane 
  the 
  grub 
  destroys 
  a 
  very 
  large 
  amount 
  

   of 
  tissue, 
  partly 
  by 
  eating 
  and 
  swallowing 
  it, 
  and 
  partly 
  by 
  chewing 
  it 
  to 
  extract 
  

   the 
  sap. 
  The 
  tunnels 
  made 
  are 
  not 
  infrequently 
  two 
  feet 
  long, 
  but 
  generally 
  they 
  

   do 
  not 
  extend 
  to 
  more 
  than 
  six 
  inches 
  ; 
  in 
  tunnelling 
  the 
  cane 
  the 
  grub 
  frequently 
  

   eats 
  too 
  close 
  to 
  the 
  rind, 
  and 
  in 
  doing 
  so 
  it 
  makes 
  small 
  rupture 
  holes 
  about 
  the 
  

   size 
  of 
  a 
  pin's 
  head. 
  The 
  borer 
  grubs 
  can 
  be 
  readily 
  located 
  by 
  the 
  presence 
  of 
  these 
  

   holes, 
  which 
  stand 
  out 
  somewhat 
  conspicuously 
  as 
  a 
  result 
  of 
  the 
  rind 
  in 
  their 
  

   immediate 
  vicinity 
  being 
  of 
  a 
  rather 
  lighter 
  shade 
  than 
  elsewhere. 
  The 
  full-grown 
  

   grub 
  measures 
  somewhat 
  more 
  than 
  half 
  an 
  inch 
  in 
  length, 
  and 
  is 
  legless, 
  wrinkled 
  

   and 
  yellowish 
  grey 
  in 
  body 
  colour, 
  the 
  head 
  being 
  light 
  reddish 
  brown. 
  The 
  fifth 
  

   and 
  sixth 
  adbominal 
  segments 
  are 
  greatly 
  swollen 
  ventrally. 
  

  

  Fi°\ 
  

  

  1. 
  Rhabdocnemis 
  obscura, 
  Boisd., 
  X 
  3. 
  

  

  The 
  full-grown 
  grub 
  prepares 
  for 
  pupation 
  by 
  eating 
  a 
  hole 
  in 
  the 
  rind 
  of 
  the 
  

   cane 
  somewhat 
  less 
  than 
  a 
  quarter 
  of 
  an 
  inch 
  in 
  length, 
  and 
  at 
  a 
  short 
  distance 
  

   above 
  this 
  hole 
  it 
  pupates 
  in 
  a 
  cocoon 
  of 
  fibres 
  separated 
  from 
  the 
  tissue 
  in 
  which 
  

   it 
  has 
  been 
  tunnelling. 
  The 
  cocoon 
  is 
  extremely 
  strong, 
  and 
  as 
  it 
  is 
  very 
  difficult 
  

   for 
  anything 
  to 
  penetrate 
  it, 
  the 
  pupa 
  is 
  generally 
  immune 
  from 
  the 
  attacks 
  of 
  the 
  

   small 
  brown 
  ant 
  (Pheidole 
  megacephala, 
  F.) 
  ; 
  were 
  the 
  cocoon 
  less 
  strongly 
  made 
  

   a 
  large 
  proportion 
  of 
  the 
  pupae 
  would 
  undoubtedly 
  perish, 
  for 
  this 
  ant 
  is 
  extremely 
  

   voracious 
  and 
  a 
  very 
  formidable 
  predator. 
  

  

  