﻿INSECTS 
  IN 
  SUGAR-CANE 
  PLANTATIONS 
  IN 
  FIJI. 
  35 
  

  

  A 
  Second 
  Species 
  of 
  Sugar-Cane 
  Army-Worm 
  (Cirphis 
  loreyi, 
  Dup.). 
  

  

  The 
  army-worms 
  of 
  this 
  species 
  are 
  occasionally 
  destructive 
  in 
  the 
  cane 
  areas 
  

   although 
  generally 
  their 
  attacks 
  are 
  confined 
  to 
  a 
  few 
  stools 
  along 
  the 
  edges 
  of 
  

   fields. 
  During 
  a 
  residence 
  of 
  several 
  years 
  in 
  Fiji 
  the 
  writer 
  has 
  seen 
  only 
  one 
  

   attack 
  in 
  which 
  the 
  damage 
  was 
  at 
  all 
  serious 
  ; 
  this 
  occurred 
  in 
  an 
  eleven-month- 
  

   old 
  crop 
  of 
  plant 
  cane, 
  and 
  was 
  so 
  severe 
  that 
  many 
  of 
  the 
  leaves 
  were 
  stripped 
  

   down 
  to 
  the 
  midrib. 
  This 
  species 
  occurs 
  in 
  the 
  old 
  word 
  tropics, 
  and 
  in 
  Africa 
  

   it 
  is 
  a 
  serious 
  pest 
  of 
  maize. 
  

  

  Minahs, 
  hornets 
  and 
  the 
  Tachinid, 
  Sturmia 
  bimaculata, 
  Htg., 
  keep 
  this 
  pest 
  

   in 
  check, 
  and 
  the 
  use 
  of 
  artificial 
  control 
  measures 
  is 
  unnecessary. 
  

  

  The 
  Mauritius 
  Bean 
  Army-Worm 
  (Prodenia 
  Utura, 
  ¥.). 
  

  

  Mauritius 
  bean 
  is 
  extensively 
  used 
  on 
  all 
  the 
  plantations, 
  it 
  being 
  part 
  of 
  the 
  

   normal 
  rotation 
  to 
  long-fallow 
  land 
  once 
  every 
  four 
  years 
  with 
  Mauritius 
  bean 
  

   as 
  a 
  covering 
  crop, 
  which 
  is 
  eventually 
  ploughed 
  in 
  as 
  a 
  green 
  manure. 
  The 
  

   Mauritius 
  bean 
  army-worm 
  occurs 
  in 
  every 
  fallow 
  field 
  and 
  is 
  responsible 
  for 
  a 
  

   very 
  appreciable 
  check 
  to 
  the 
  growth 
  of 
  the 
  crop. 
  

  

  The 
  eggs 
  of 
  this 
  moth 
  are 
  laid 
  in 
  clusters 
  or 
  nests, 
  each 
  of 
  which 
  contains 
  from 
  

   500 
  to 
  700 
  eggs, 
  the 
  usual 
  spots 
  chosen 
  for 
  egg-laying 
  being 
  the 
  leaves 
  of 
  the 
  food- 
  

   plant. 
  The 
  caterpillars 
  hatch 
  out 
  after 
  an 
  incubation 
  period 
  of 
  three 
  days, 
  and 
  

   immediately 
  commence 
  eating 
  small 
  irregular 
  patches 
  on 
  the 
  under-surface 
  of 
  the 
  

   leaves, 
  but 
  as 
  they 
  grow 
  older 
  they 
  eat 
  through 
  the 
  leaf 
  tissue, 
  destroying 
  epidermis, 
  

   ground 
  tissue 
  and 
  small 
  veins. 
  The 
  caterpillars 
  also 
  attack 
  cotton, 
  tobacco 
  and 
  

   cacao, 
  and 
  the 
  writer 
  has 
  recently 
  bred 
  them 
  from 
  the 
  fruits 
  of 
  the 
  " 
  ivi 
  " 
  or 
  

   Tahitian 
  chestnut. 
  They 
  are 
  full 
  grown 
  in 
  three 
  weeks, 
  and 
  then 
  pupate 
  in 
  earthern 
  

   cells 
  two 
  or 
  three 
  inches 
  below 
  the 
  ground, 
  the 
  moth 
  emerging 
  after 
  a 
  pupal 
  period 
  

   of 
  eleven 
  or 
  twelve 
  days. 
  

  

  The 
  enemies 
  of 
  this 
  insect 
  are 
  the 
  minah, 
  the 
  hornet 
  and 
  the 
  small 
  brown 
  ant 
  

   (Pheidole 
  megacephala, 
  F.). 
  The 
  ant 
  destroys 
  large 
  numbers 
  of 
  the 
  eggs. 
  Remedial 
  

   measures 
  are 
  not 
  at 
  present 
  required 
  for 
  the 
  control 
  of 
  this 
  pest. 
  

  

  The 
  Moth 
  Borer 
  Of 
  Cane 
  (Trachycentra 
  chlorogramma, 
  Meyr.). 
  

  

  The 
  larvae 
  of 
  this 
  Tineid 
  moth 
  are 
  occasionally 
  found 
  tunnelling 
  cane, 
  and 
  

   causing 
  a 
  slight 
  amount 
  of 
  damage. 
  Their 
  work 
  has 
  usually 
  been 
  most 
  conspicuous 
  

   in 
  low-lying 
  reclaimed 
  tiri 
  fields, 
  which 
  frequently 
  contain 
  a 
  considerable 
  proportion 
  

   of 
  sickly 
  canes. 
  Some 
  of 
  these 
  moth 
  borers 
  have 
  been 
  found 
  in 
  half-rotten 
  cane, 
  

   but 
  others 
  have 
  been 
  found 
  in 
  soft 
  light-coloured 
  Badila 
  stalks 
  which 
  were 
  standing 
  

   up 
  well 
  and 
  were 
  far 
  from 
  being 
  rotten, 
  although 
  they 
  were 
  of 
  a 
  somewhat 
  sickly 
  

   appearance. 
  No 
  stools 
  of 
  perfectly 
  healthy 
  cane 
  have 
  been 
  attacked 
  by 
  this 
  insect. 
  

   The 
  full-grown 
  larva 
  is 
  about 
  25 
  mm. 
  in 
  length, 
  and 
  lives 
  in 
  a 
  case 
  which 
  it 
  drags 
  

   about 
  from 
  place 
  to 
  place 
  ; 
  this 
  case 
  is 
  a 
  spun 
  web 
  to 
  which 
  numerous 
  small 
  

   particles 
  of 
  cane, 
  earth 
  and 
  vegetable 
  debris 
  are 
  attached. 
  The 
  case 
  affords 
  a 
  

   considerable 
  amount 
  of 
  protection 
  to 
  the 
  larva, 
  which 
  is 
  able 
  to 
  wriggle 
  into 
  or 
  

   out 
  of 
  it 
  with 
  astonishing 
  rapidity. 
  

  

  The 
  damage 
  caused 
  by 
  this 
  species 
  bears 
  some 
  resemblance 
  to 
  the 
  work 
  of 
  the 
  

   beetle 
  borer, 
  but 
  it 
  differs 
  from 
  it 
  in 
  several 
  important 
  respects. 
  The 
  tunnels 
  of 
  the 
  

   moth 
  are 
  wider, 
  shorter 
  and 
  more 
  irregular 
  than 
  those 
  of 
  the 
  beetle 
  borer 
  and 
  they 
  

   (C572) 
  o2 
  

  

  