﻿280 
  BRITISH 
  LEPIDOPTERA. 
  

  

  ance 
  of 
  them 
  when 
  laid 
  on 
  leaves 
  and 
  on 
  paper, 
  respectively, 
  may 
  be 
  

   different, 
  and 
  partly 
  account 
  for 
  the 
  difference 
  in 
  colour 
  noted.] 
  

  

  Habits 
  of 
  larva. 
  — 
  The 
  young 
  larvae 
  hatch 
  very 
  soon 
  after 
  the 
  

   eggs 
  are 
  laid 
  (comparing 
  thus, 
  remarkably, 
  with 
  those 
  of 
  Oidae- 
  

   matopJiorus 
  lithodactyla). 
  Those 
  under 
  observation 
  burrowed 
  at 
  once 
  

   into 
  the 
  flower-buds 
  of 
  Erica 
  or 
  Stachys, 
  and, 
  if 
  an 
  unhatched 
  egg 
  

   be 
  in 
  the 
  way 
  of 
  a 
  larva, 
  it 
  will 
  devour 
  it, 
  as 
  seen 
  in 
  the 
  case 
  of 
  two 
  

   larvae, 
  one 
  of 
  which 
  had 
  attacked 
  a 
  third 
  egg 
  without 
  having 
  well 
  

   cleared 
  up 
  the 
  second 
  out 
  of 
  a 
  little 
  group 
  of 
  four 
  ; 
  its 
  anal 
  end, 
  at 
  

   the 
  time, 
  being 
  comfortably 
  placed 
  between 
  flower-buds 
  of 
  Erica 
  

   tetralix. 
  A 
  week 
  later 
  (September 
  8th, 
  1904), 
  the 
  plants 
  were 
  ex- 
  

   amined 
  ; 
  the 
  Stachys 
  had 
  not 
  kept 
  well, 
  and 
  some 
  larvae 
  appeared 
  to 
  

   have 
  perished 
  in 
  consequence; 
  some 
  others 
  had 
  wandered 
  off 
  the 
  

   plants, 
  and 
  of 
  others 
  no 
  trace 
  could 
  be 
  found. 
  Of 
  the 
  living 
  larvae, 
  some 
  

   were 
  still 
  small 
  in 
  the 
  1st 
  instar, 
  others 
  not 
  very 
  far 
  from 
  moult, 
  and 
  not 
  

   very 
  much 
  smaller 
  than 
  some 
  of 
  those 
  in 
  2nd 
  instar 
  ; 
  their 
  being 
  in 
  the 
  

   1st 
  instar 
  was 
  proved 
  by 
  the 
  size 
  of 
  the 
  head, 
  which 
  agreed 
  precisely 
  

   with 
  that 
  of 
  newly-hatched 
  larvae. 
  The 
  larva, 
  fullgrownin 
  1st 
  instar, 
  was 
  

   all 
  but 
  2mm. 
  long, 
  very 
  smooth, 
  the 
  hairs 
  looking 
  very 
  minute 
  ; 
  the 
  

   prolegs 
  and 
  claspers 
  very 
  small, 
  and 
  short, 
  in 
  proportion 
  to 
  its 
  size, 
  

   being, 
  of 
  course, 
  those 
  of 
  first 
  skin 
  ; 
  those 
  of 
  second 
  skin 
  larvae 
  

   were 
  of 
  due 
  proportion 
  ; 
  these 
  larvae 
  were 
  over 
  2mm. 
  long, 
  one 
  or 
  two 
  

   nearly 
  3-0mm., 
  but 
  none 
  were 
  fullgrown 
  in 
  this 
  instar. 
  The 
  favourite 
  

   food, 
  at 
  this 
  stage, 
  seemed 
  evidently 
  to 
  be 
  the 
  filaments 
  of 
  the 
  stamens, 
  

   both 
  of 
  the 
  heath 
  and 
  of 
  the 
  Stachys, 
  but 
  any 
  other 
  part 
  of 
  the 
  floral 
  

   interior 
  seemed 
  to 
  be 
  eaten. 
  The 
  interior 
  of 
  the 
  flower 
  is 
  reached 
  

   whilst 
  it 
  is 
  still 
  a 
  bud, 
  by 
  perforating 
  the 
  corolla 
  with 
  a 
  minute 
  hole. 
  

   Second 
  stage 
  larvae 
  were 
  twice 
  found 
  at 
  large 
  on 
  the 
  plant, 
  being 
  

   driven 
  out 
  of 
  the 
  Stachys 
  flowers 
  by 
  their 
  decay. 
  In 
  the 
  case 
  of 
  heads 
  

   of 
  Erica 
  so 
  little 
  advanced 
  that 
  the 
  corollae 
  are 
  still 
  invisible, 
  the 
  

   larva 
  bores 
  into 
  the 
  mass 
  of 
  flowers 
  from 
  the 
  top, 
  and 
  throws 
  out 
  some 
  

   frass 
  at 
  the 
  place 
  where 
  it 
  entered. 
  In 
  the 
  case 
  of 
  entering 
  a 
  flower, 
  the 
  

   frass 
  is 
  not 
  extruded, 
  but 
  left 
  inside 
  the 
  corolla. 
  Unless 
  the 
  small 
  hole 
  of 
  

   entrance 
  can 
  be 
  found, 
  the 
  larva 
  in 
  a 
  flower 
  gives 
  no 
  indication 
  of 
  its 
  

   presence 
  so 
  long 
  as 
  it 
  stays 
  there. 
  It 
  is 
  difficult 
  to 
  say 
  whether 
  it 
  

   should 
  be 
  called 
  an 
  internal-feeder, 
  or 
  no. 
  \Yhen 
  it 
  is 
  small, 
  the 
  residence 
  

   is 
  always 
  within 
  a 
  flower; 
  I 
  doubt 
  whether 
  it 
  could 
  exist 
  on 
  leaves, 
  

   ■though 
  young 
  leaf-buds 
  might, 
  perhaps, 
  serve. 
  It 
  will 
  live 
  comfort- 
  

   ably 
  in 
  the 
  head 
  of 
  unopened 
  flowers 
  of 
  Pelargonium 
  or 
  Erica, 
  eating 
  

   the 
  filaments, 
  and 
  even 
  the 
  anthers 
  of 
  the 
  stamens, 
  and, 
  to 
  get 
  at 
  

   them, 
  acts 
  more 
  as 
  a 
  burrower 
  or 
  internal-feeder 
  than 
  when 
  it 
  merely 
  

   gets 
  into 
  a 
  fairly-developed 
  flower 
  of 
  Erica 
  or 
  Stachys. 
  It 
  preserves 
  

   precisely 
  the 
  same 
  habits 
  up 
  to 
  full-growth, 
  except 
  when 
  it 
  is 
  too 
  large 
  

   to 
  get 
  into 
  the 
  flower, 
  and 
  so 
  has 
  to 
  be 
  satisfied 
  with 
  getting 
  only 
  the 
  

   anterior 
  segments 
  inside. 
  It 
  will, 
  however, 
  moult 
  into 
  last 
  skin 
  inside 
  

   the 
  bell 
  of 
  a 
  flower 
  of 
  Erica 
  tetralix. 
  I 
  fed 
  most 
  of 
  mine 
  on 
  this 
  

   plant, 
  as 
  I 
  found 
  Stachys 
  inconvenient 
  in 
  several 
  ways. 
  Like 
  several 
  

   "plumes" 
  that 
  I 
  have 
  been 
  able 
  to 
  follow 
  through 
  with 
  precision, 
  this 
  

   species 
  has 
  four 
  larval 
  instars. 
  In 
  other 
  cases, 
  whether 
  the 
  instars 
  be 
  

   four 
  or 
  five 
  is 
  a 
  matter 
  of 
  inference, 
  or 
  of 
  measuring 
  the 
  diameters 
  of 
  

   the 
  larval 
  heads, 
  which 
  is 
  a 
  very 
  reliable 
  method 
  of 
  determining 
  the 
  

   point, 
  but 
  here 
  I 
  was 
  able 
  to 
  follow 
  individual 
  larvae 
  from 
  the 
  egg 
  

   onwards. 
  The 
  following 
  data, 
  referring 
  to 
  the 
  changes 
  of 
  some 
  of 
  the 
  

   latest 
  larvae, 
  may 
  prove 
  interesting 
  : 
  — 
  

  

  