﻿126 
  PROCEEDINGS 
  OF 
  THE 
  FOrRTH 
  ENTOirOLOGlCAL 
  MEETING 
  

  

  plant. 
  Mootlia 
  is 
  a 
  troublesome 
  weed 
  in 
  many 
  parts 
  of 
  the 
  country 
  and 
  

   it 
  takes 
  several 
  years 
  of 
  careful 
  uprooting 
  along 
  with 
  the 
  root-stocks 
  

   to 
  eradicate 
  it 
  from 
  lands 
  newly 
  brought 
  under 
  cultivation. 
  Although 
  

   it 
  serves 
  partly 
  as 
  food 
  for 
  cattle, 
  there 
  are 
  some 
  varieties 
  of 
  it 
  which 
  

   are 
  not 
  liked 
  by 
  cattle. 
  It 
  grows 
  very 
  profusely 
  and 
  luxuriantly 
  and 
  

   the 
  influence 
  of 
  this 
  borer 
  aided 
  by 
  the 
  weevil 
  borer 
  referred 
  to 
  at 
  page 
  

   119 
  of 
  this 
  volume 
  seems 
  to 
  be 
  very 
  small 
  as 
  a 
  check. 
  

  

  In 
  the 
  neighbourhood 
  of 
  Pusa 
  this 
  insect 
  is 
  observed 
  to 
  be 
  active 
  

   throughout 
  the 
  year. 
  The 
  caterpillars 
  do 
  not 
  bore 
  down 
  from 
  the 
  

   top 
  but 
  effect 
  their 
  entrance 
  into 
  the 
  centre 
  of 
  the 
  leaf-bundle 
  or 
  into 
  

   the 
  stem 
  in 
  advanced 
  plants, 
  through 
  the 
  lower 
  leaf-sheaths 
  and 
  tunnel 
  

   up 
  and 
  down 
  the 
  central 
  region 
  but 
  never 
  enter 
  the 
  root-stock. 
  The 
  

   result 
  of 
  course 
  is 
  dead-heart 
  in 
  young 
  plants 
  but 
  in 
  the 
  fully 
  developed 
  

   stem 
  the 
  effect 
  is 
  hardly 
  apparent 
  externally. 
  Pupation 
  takes 
  place 
  

   inside 
  the 
  stem 
  of 
  the 
  affected 
  plants 
  in 
  an 
  elongated 
  silken 
  coco- 
  n 
  

   formed 
  lining 
  either 
  the 
  tunnel 
  or 
  the 
  outer 
  leaf-sheaths, 
  the 
  moth 
  

   emerging 
  after 
  about 
  five 
  days. 
  Ordinarily 
  the 
  life-cycle 
  seems 
  to 
  be 
  

   completed 
  within 
  about 
  three 
  weeks. 
  

  

  Full-grown 
  larvae 
  measure 
  about 
  12 
  to 
  15 
  mm. 
  in 
  length 
  and 
  about 
  

   1-5 
  mm. 
  in 
  thickness 
  across 
  the 
  anterior 
  part 
  of 
  the 
  body 
  which 
  tapers 
  

   gradually 
  and 
  slightly 
  hindwards. 
  They 
  have 
  a 
  slender, 
  longish 
  and 
  

   dorsoventrally 
  compressed 
  appearance. 
  The 
  head 
  is 
  slightly 
  smaller 
  

   than 
  the 
  prothorax 
  which 
  has 
  a 
  distinct 
  shield 
  of 
  the 
  same 
  colour 
  as 
  

   the 
  head. 
  Spiracles 
  are 
  round, 
  a 
  narrow 
  brown 
  or 
  black 
  rim 
  enclosing 
  

   a 
  clear 
  space. 
  Running 
  along 
  and 
  connecting 
  the 
  spiracles 
  a 
  tracheal 
  

   tube 
  is 
  more 
  or 
  less 
  visible 
  under 
  the 
  skin. 
  There 
  are 
  five 
  pairs 
  of 
  

   equally 
  developed 
  prolegs 
  with 
  booklets 
  arranged 
  in 
  a 
  circle. 
  In 
  colo- 
  

   ration 
  the 
  larvse 
  vary 
  a 
  good 
  deal, 
  the 
  following 
  three 
  types 
  occurring 
  

   commonly 
  : 
  — 
  (1) 
  Body 
  pale 
  yellow 
  with 
  the 
  mesothorax, 
  metathorax 
  

   and 
  to 
  a 
  less 
  extent 
  the 
  first 
  two 
  abdominal 
  segments 
  purplish 
  and 
  

   head 
  brownish 
  yellow. 
  (2) 
  Body 
  green 
  with 
  the 
  mesothorax, 
  meta- 
  

   thorax 
  and 
  the 
  first 
  two 
  abdominal 
  segments 
  smoky 
  or 
  dusky 
  and 
  head 
  

   pale 
  yellow 
  with 
  a 
  greenish 
  tinge. 
  (3) 
  Body 
  uniform 
  pale 
  yellow 
  with 
  

   dark 
  grey 
  or 
  black 
  head. 
  Green 
  larvse 
  are 
  the 
  commonest 
  of 
  all. 
  

  

  The 
  pupa 
  is 
  about 
  5 
  to 
  7 
  mm. 
  long, 
  cylindrical, 
  tapering 
  slightly 
  

   towards 
  hind 
  end. 
  Each 
  of 
  the 
  third 
  to 
  eighth 
  abdominal 
  segments 
  

   has 
  two 
  transverse 
  rows 
  of 
  spines 
  on 
  the 
  dorsal 
  side, 
  the 
  row 
  at 
  thfr 
  

   anterior 
  part 
  consisting 
  of 
  straight 
  posteriorly 
  directed 
  spines 
  and 
  that 
  

   at 
  the 
  posterior 
  part 
  of 
  very 
  small 
  spines. 
  The 
  ninth 
  abdominal 
  seg- 
  

   ment 
  has 
  a 
  single 
  row 
  of 
  large 
  spines 
  the 
  tips 
  of 
  all 
  or 
  some 
  of 
  which 
  

   are 
  curved 
  up 
  anteriorly. 
  The 
  hind 
  end 
  is 
  rounded 
  and 
  has 
  a 
  pair 
  

   of 
  small 
  pyramidal 
  papillae 
  surrounded 
  with 
  hairs. 
  The 
  colour 
  of 
  the- 
  

  

  