﻿36 
  ROBERT 
  VEITCH. 
  

  

  contain 
  a 
  much 
  rougher, 
  darker 
  coloured 
  frass. 
  Other 
  points 
  of 
  importance 
  in 
  the 
  

   mode 
  of 
  attack 
  of 
  this 
  pest 
  are 
  firstly 
  the 
  fact 
  that, 
  unlike 
  the 
  beetle 
  borer, 
  it 
  swallows 
  

   all 
  the 
  cane 
  it 
  chews, 
  and 
  secondly 
  that 
  it 
  frequently 
  leaves 
  its 
  tunnel 
  and 
  moves 
  up 
  

   the 
  cane-stalk 
  or 
  even 
  to 
  another 
  stalk, 
  where 
  it 
  commences 
  a 
  new 
  tunnel. 
  Otherwise 
  

   the 
  larva 
  destroys 
  cane 
  in 
  a 
  manner 
  somewhat 
  similar 
  to 
  the 
  beetle 
  borer 
  

   by 
  eating 
  tunnels 
  along 
  the 
  stalks, 
  destroying 
  large 
  quantities 
  of 
  tissue 
  and 
  lowering 
  

   the 
  sugar 
  content 
  of 
  the 
  untunnelled 
  portions 
  of 
  the 
  affected 
  stalks. 
  

  

  The 
  full-grown 
  larva 
  pupates 
  in 
  an 
  extremely 
  tough 
  case 
  made 
  of 
  small 
  pieces 
  of 
  

   cane 
  fibre 
  overlapping 
  each 
  other 
  like 
  roofing 
  tiles 
  ; 
  it 
  is 
  securely 
  closed 
  at 
  both 
  ends 
  

   and 
  must 
  afford 
  very 
  good 
  protection 
  to 
  the 
  pupa. 
  The 
  pupa 
  is 
  formed 
  sometimes 
  

   in 
  the 
  old 
  larval 
  tunnel, 
  and 
  at 
  other 
  times 
  behind 
  the 
  leaf-sheaths 
  or 
  under 
  debris, 
  

   the 
  pupal 
  period 
  lasting 
  for 
  three 
  weeks. 
  

  

  The 
  burning 
  of 
  the 
  trash 
  after 
  harvesting 
  and 
  the 
  exposure 
  of 
  tunnelled 
  stalks 
  to 
  

   the 
  heat 
  of 
  the 
  sun 
  will 
  largely 
  check 
  the 
  increase 
  of 
  this 
  insect 
  should 
  it 
  ever 
  show 
  

   signs 
  of 
  attacking 
  sound 
  cane. 
  

  

  The 
  Cane 
  Leaf-Miner 
  (Cosmopteryx 
  sp. 
  n.). 
  

  

  The 
  larva 
  of 
  this 
  very 
  small 
  and 
  beautiful 
  moth 
  mines 
  in 
  the 
  midribs 
  of 
  cane, 
  being 
  

   particularly 
  abundant 
  in 
  young 
  plant 
  fields, 
  where 
  it 
  does 
  a 
  slight 
  amount 
  of 
  damage 
  

   by 
  tunnelling 
  along 
  the 
  midrib, 
  interfering 
  with 
  the 
  supply 
  of 
  sap 
  to 
  the 
  leaves 
  and 
  

   discolouring 
  the 
  tissues 
  surrounding 
  its 
  tunnels. 
  This 
  species 
  is 
  well 
  controlled 
  by 
  

   parasites. 
  

  

  The 
  Hornet 
  (Polistes 
  macaensis, 
  F.). 
  

  

  The 
  common 
  hornet 
  of 
  the 
  cane-fields 
  is 
  far 
  from 
  being 
  a 
  pest, 
  but 
  it 
  is 
  so 
  intimately 
  

   connected 
  with 
  the 
  sugar 
  plantations 
  that 
  no 
  reference 
  to 
  the 
  insects 
  of 
  the 
  cane- 
  

   fields 
  would 
  be 
  complete 
  without 
  an 
  outline 
  of 
  its 
  life-history. 
  

  

  This 
  hornet 
  is 
  only 
  a 
  recent 
  introduction, 
  but 
  it 
  has 
  already 
  become 
  one 
  of 
  the 
  

   commonest 
  insects 
  in 
  the 
  islands, 
  and 
  has 
  probably 
  attracted 
  more 
  general 
  interest 
  

   than 
  any 
  other 
  species 
  in 
  Fiji. 
  It 
  is 
  widely 
  distributed 
  throughout 
  India 
  and 
  the 
  

   East, 
  and 
  appears 
  to 
  have 
  reached 
  these 
  islands 
  some 
  fifteen 
  years 
  ago, 
  having 
  in 
  

   all 
  probability 
  been 
  introduced 
  on 
  a 
  labour 
  ship 
  from 
  India. 
  It 
  showed 
  up 
  first 
  at 
  

   Suva 
  and 
  has 
  now 
  spread 
  all 
  over 
  Viti 
  Levu 
  ; 
  it 
  has 
  also 
  gained 
  a 
  footing 
  in 
  Vanua 
  

   Levu, 
  and 
  in 
  a 
  few 
  years 
  time 
  it 
  will 
  doubtless 
  be 
  generally 
  distributed 
  throughout 
  

   the 
  islands. 
  

  

  The 
  life-history 
  of 
  this 
  species 
  may 
  be 
  summarised 
  as 
  follows 
  : 
  — 
  A 
  fertilised 
  female 
  

   that 
  has 
  hibernated 
  during 
  August 
  and 
  September 
  commences 
  nest-building 
  at 
  the 
  

   beginning 
  of 
  October. 
  The 
  cells 
  of 
  the 
  nest 
  are 
  made 
  of 
  the 
  usual 
  fibrous 
  material 
  

   mixed 
  with 
  cement, 
  and 
  in 
  each 
  the 
  female 
  lays 
  a 
  small 
  greyish 
  white 
  egg 
  from 
  which 
  

   the 
  young 
  larva 
  hatches 
  in 
  a 
  few 
  days. 
  At 
  first 
  the 
  larva 
  is 
  fed 
  on 
  sugary 
  substances, 
  

   but 
  after 
  it 
  is 
  a 
  few 
  days 
  old 
  the 
  diet 
  is 
  changed 
  to 
  an 
  insect 
  one. 
  The 
  larva 
  pupates 
  

   14 
  to 
  18 
  days 
  after 
  hatching, 
  and 
  the 
  imago 
  emerges 
  after 
  a 
  pupal 
  period 
  of 
  15 
  or 
  16 
  days; 
  

   after 
  the 
  emergence 
  of 
  the 
  first 
  new 
  generation 
  progress 
  on 
  the 
  nest 
  is 
  very 
  rapid, 
  and 
  

   by 
  April 
  it 
  may 
  be 
  as 
  large 
  as 
  12 
  inches 
  in 
  diameter. 
  Towards 
  the 
  end 
  of 
  April 
  males 
  

   and 
  females 
  appear 
  in 
  equal 
  numbers 
  whereas 
  previously 
  the 
  new 
  hornets 
  emerging 
  

   were 
  nearly 
  all 
  females. 
  This 
  last 
  generation 
  leaves 
  the 
  nest 
  and 
  the 
  hornets 
  hide 
  

   in 
  sheltered 
  spots, 
  emerging 
  on 
  sunny 
  days 
  in 
  June 
  and 
  July 
  to 
  mate, 
  but 
  by 
  the 
  

  

  