﻿LIFE-HISTORY 
  OF 
  AUSTRALIAN 
  MOTH-LACEWING, 
  ITHONE 
  FUSCA, 
  NEWMAN. 
  217 
  

  

  condition 
  of 
  the 
  large 
  pinaculum 
  on 
  either 
  side 
  of 
  the 
  metathorax 
  is 
  shown 
  in 
  text- 
  

   fig. 
  7. 
  It 
  is 
  no 
  longer 
  possible 
  to 
  pick 
  out 
  the 
  primary 
  setae 
  with 
  certainty 
  on 
  the 
  

   abdominal 
  segments, 
  as 
  the 
  lengths 
  of 
  the 
  secondary 
  setae 
  are 
  by 
  now 
  very 
  nearly 
  

   the 
  same. 
  

  

  

  > 
  

  

  -= 
  r 
  ^=i>-,'":,'-''.'.. 
  ;i 
  

  

  . 
  — 
  i. 
  . 
  ' 
  » 
  . 
  • 
  . 
  

  

  4? 
  -%?.■.:■.•'.•>'. 
  

  

  

  

  Fig. 
  7. 
  Ithone 
  fusca, 
  Newm., 
  third 
  larval 
  

   instar; 
  large 
  pinaculum 
  of 
  metathorax, 
  

   showing 
  the 
  great 
  increase 
  in 
  the 
  number 
  

   of 
  secondary 
  setae 
  ( 
  X 
  112). 
  

  

  Fourth 
  Larval 
  Instar 
  (Plate 
  iv, 
  fig. 
  5 
  ; 
  text-fig. 
  8). 
  

  

  In 
  this 
  instar, 
  the 
  head 
  is 
  further 
  reduced 
  in 
  size 
  in 
  comparison 
  with 
  the 
  prothorax, 
  

   and 
  is 
  now 
  less 
  than 
  half 
  as 
  wide 
  as 
  the 
  latter, 
  and 
  considerably 
  shorter, 
  as 
  can 
  be 
  

   seen 
  from 
  text-fig. 
  8. 
  The 
  turning-up 
  of 
  the 
  mouth-parts 
  is 
  very 
  noticeable, 
  as 
  is 
  

   also 
  the 
  development 
  of 
  the 
  swollen 
  ventral 
  portion 
  of 
  the 
  head 
  beneath 
  the 
  maxillae. 
  

  

  Fig. 
  S. 
  Ithone 
  fusca, 
  Newm., 
  fourth 
  larval 
  instar; 
  

   lateral 
  view 
  of 
  head 
  and 
  prothorax 
  ( 
  x 
  20) 
  . 
  

  

  The 
  upper 
  claw 
  of 
  the 
  fore 
  tarsus 
  is 
  now 
  about 
  as 
  long 
  as 
  the 
  maxilla 
  ; 
  in 
  all 
  previous 
  

   instars 
  it 
  is 
  considerably 
  shorter. 
  The 
  primary 
  chaetotaxy 
  has 
  disappeared, 
  or 
  

   can 
  no 
  longer 
  be 
  recognised 
  ; 
  the 
  setae 
  on 
  the 
  head 
  and 
  prothorax 
  are 
  shown 
  as 
  in 
  

  

  