﻿PJIOCEEDTXGS 
  OF 
  THE 
  FOURTH 
  ENTOilOLOGICAL 
  MEETING 
  123 
  

  

  Diatraea 
  venosaia, 
  Wlk. 
  

  

  A 
  notable 
  observation 
  with 
  regard 
  to 
  this 
  borer 
  is 
  that 
  it 
  was 
  found 
  

   in 
  December 
  1919 
  to 
  occur 
  as 
  a 
  regular 
  pest 
  of 
  sugarcane 
  at 
  Cuttack 
  

   where 
  no 
  juar 
  {Andropogon 
  sorghum) 
  is 
  grown 
  and 
  hardly 
  any 
  Saccharvm 
  

   spontaneum 
  occurs. 
  At 
  Pusa, 
  where 
  there 
  are 
  extensive 
  tracts 
  under 
  

   juar 
  and 
  S. 
  spontaneum., 
  D. 
  venosata 
  occurs 
  very 
  commonly 
  in 
  S. 
  sponta- 
  

   neum 
  and 
  juar 
  but 
  very 
  rarely 
  in 
  sugarcane. 
  

  

  Ghilo 
  torrentellus. 
  

  

  (Plate 
  XX.) 
  

   Foodplant— 
  jRar^*' 
  and 
  Batri 
  {Saccharum 
  spontaneum). 
  

  

  It 
  has 
  been 
  referred 
  to 
  as 
  a 
  Pyralid 
  Borer 
  (PI. 
  64, 
  fig. 
  1) 
  in 
  the 
  first 
  

   paper 
  {Proc. 
  Third 
  Entl. 
  Meeting, 
  p. 
  393). 
  The 
  stems 
  are 
  bored 
  in 
  

   their 
  central 
  part 
  and 
  converted 
  into 
  hollow 
  tubes. 
  When 
  the 
  larva 
  

   bores 
  near 
  the 
  top 
  the 
  heart 
  shoot 
  dies 
  and 
  dries. 
  Otherwise 
  there 
  

   is 
  hardly 
  any 
  prominent 
  external 
  symptom. 
  The 
  caterpillars 
  are 
  found 
  

   in 
  very 
  large 
  numbers. 
  They 
  may 
  be 
  looked 
  for 
  in 
  thin 
  reedlike 
  varieties 
  

   of 
  sugarcane, 
  although 
  none 
  has 
  been 
  observed 
  in 
  this 
  plant 
  yet. 
  

  

  The 
  young 
  and 
  full-grown 
  caterpillars 
  resemble 
  one 
  another 
  in 
  

   appearance. 
  The 
  full-grown 
  larva 
  is 
  about 
  35 
  mm. 
  long 
  when 
  fully 
  

   stretched. 
  The 
  mesothorax 
  is 
  thicker 
  than 
  other 
  segments 
  and 
  

   measures 
  about 
  3-5 
  mm. 
  across 
  and 
  from 
  this 
  segment 
  the 
  body 
  tapers 
  

   both 
  ways 
  slightly 
  and 
  gradually. 
  The 
  shape 
  is 
  cylindrical 
  but 
  looks 
  

   slightly 
  compressed 
  in 
  the 
  dorsoventral 
  plane. 
  The 
  head 
  is 
  yellow, 
  

   glossy, 
  with 
  the 
  buccal 
  region 
  and 
  appendages 
  dark 
  brown. 
  The 
  

   prothoracic 
  shield 
  is 
  not 
  prominent. 
  The 
  thoracic 
  segments 
  have 
  

   a 
  tinge 
  of 
  the 
  same 
  colour 
  as 
  the 
  head. 
  The 
  segments 
  of 
  the 
  body 
  

   are 
  not 
  very 
  prominently 
  distinguished. 
  The 
  skin 
  of 
  the 
  whole 
  

   body 
  has 
  a 
  shiny 
  appearance 
  and 
  is 
  naked, 
  the 
  primary 
  hairs 
  

   being 
  minute 
  and 
  black. 
  The 
  spiracles 
  are 
  elongated 
  oval, 
  wholly 
  

   light-brown 
  with 
  a 
  narrow 
  dark 
  rira. 
  Along 
  the 
  spiracles 
  a 
  tracheal 
  

   tube 
  is 
  faintly 
  visible 
  under 
  the 
  skin. 
  The 
  booklets 
  on 
  the 
  five 
  

   pairs 
  of 
  short 
  but 
  equally 
  developed 
  prolegs 
  form 
  complete 
  circles. 
  

   Before 
  pupation 
  the 
  larva 
  gnaws 
  a 
  hole 
  on 
  the 
  side 
  of 
  the 
  stem, 
  

   the 
  mouth 
  of 
  the 
  hole 
  being 
  kept 
  closed 
  by 
  a 
  thin 
  membrane 
  

   of 
  the 
  bark. 
  Pupation 
  takes 
  place 
  inside 
  the 
  bored 
  stem 
  near 
  this 
  

   hole 
  in 
  a 
  sort 
  of 
  a 
  cocoon 
  formed 
  with 
  chewed 
  particles 
  spun 
  up 
  with 
  

   silk. 
  The 
  pupa 
  is 
  about 
  14 
  mm. 
  long 
  by 
  about 
  2-75 
  mm. 
  thick, 
  

   cylindrical. 
  The 
  head 
  end 
  is 
  somewhat 
  protruded 
  forwards. 
  The 
  

   dorsal 
  part 
  of 
  the 
  hind 
  end 
  is 
  protruded 
  into 
  a 
  thick 
  broad 
  wedge-shaped 
  

   process 
  which 
  possesses 
  no 
  spines 
  of 
  any 
  kind. 
  The 
  4th 
  to 
  9th 
  abdo- 
  

  

  