﻿306 
  

  

  BEITISH 
  LEPIDOPTERA. 
  

  

  fine, 
  short, 
  secondary 
  hairs, 
  shorter 
  than, 
  and 
  easily 
  differentiated 
  from, 
  

   the 
  primary 
  ones, 
  bulbous- 
  tipped. 
  Hairs 
  all 
  white, 
  not 
  long, 
  inconspicuous 
  

   (Dyar. 
  From 
  specimen 
  taken 
  in 
  Colorado). 
  Final 
  instar 
  (fullgrown): 
  

   Length 
  about 
  -5in. 
  ; 
  of 
  the 
  usual 
  stumpy 
  form 
  when 
  at 
  rest. 
  Head 
  

   small, 
  and 
  narrower 
  than 
  the 
  2nd 
  segment; 
  it 
  has 
  the 
  lobes 
  rounded, 
  

   and 
  is 
  highly 
  polished; 
  body 
  cylindrical, 
  attenuated 
  a 
  little 
  posteriorly, 
  

   each 
  segment 
  plump 
  and 
  distinct, 
  making 
  the 
  divisions 
  clearly 
  defined 
  ; 
  

   skin 
  soft, 
  and 
  sparingly 
  clothed 
  with 
  short 
  hairs 
  (see 
  p. 
  307) 
  (Porritt). 
  

   The 
  fullgrown 
  larva 
  is 
  1 
  1mm. 
  long, 
  slightly 
  attenuated 
  towards 
  both 
  ends 
  

   of 
  the 
  body, 
  with 
  weakly-developed 
  lateral 
  flange 
  bright 
  green 
  ; 
  the 
  

   dorsal 
  vessel 
  shows 
  through 
  dark 
  green 
  ; 
  two 
  white 
  subdorsal 
  lines 
  

   run 
  on 
  both 
  sides 
  of 
  this 
  ; 
  below 
  these 
  runs 
  a 
  supraspiracular 
  line, 
  

   interrupted 
  at 
  each 
  segmental 
  division, 
  consisting 
  of 
  white 
  diagonal 
  

   dashes 
  sloping 
  from 
  the 
  anterior 
  downwards 
  to 
  the 
  posterior. 
  Spiracles 
  

   ringed 
  with 
  light 
  brown 
  ; 
  lateral 
  flange 
  white. 
  Head 
  yellowish-green, 
  

   with 
  pale 
  brown 
  spots, 
  or 
  also 
  simply 
  green, 
  with 
  dark 
  brown 
  mouth- 
  

   parts. 
  Pro 
  thorax 
  and 
  anal 
  flap 
  green. 
  All 
  the 
  prolegs 
  pale 
  green 
  ; 
  

   thoracic 
  legs 
  with 
  brown 
  claws. 
  The 
  tubercles 
  are 
  small, 
  of 
  the 
  colour 
  

   of 
  the 
  body, 
  and 
  single-haired 
  ; 
  only 
  those 
  on 
  the 
  lateral 
  flange 
  bear 
  

   two 
  hairs. 
  The 
  body 
  is, 
  besides, 
  especially 
  on 
  the 
  back, 
  rather 
  thickly 
  

   beset 
  with 
  short, 
  fine, 
  white, 
  not 
  knobbed, 
  hairs 
  (only 
  distinctly 
  visible 
  

   with 
  a 
  lens). 
  (Described 
  from 
  the 
  living 
  larva) 
  (Hofmann). 
  [I 
  have 
  

   a 
  preserved 
  larva 
  that 
  was 
  taken 
  at 
  Guarda 
  (Lower 
  Engadine) 
  on 
  July 
  

   27th, 
  1900, 
  that 
  is 
  certainly 
  an 
  Amblyptilia, 
  and 
  certainly 
  not 
  cosmo- 
  

   dactyla, 
  and 
  must, 
  therefore, 
  with 
  the 
  highest 
  probability, 
  be 
  puncti- 
  

   dactyla. 
  It 
  was 
  feeding 
  on 
  geranium 
  ; 
  there 
  were 
  one 
  or 
  two 
  others, 
  

   but 
  I 
  reared 
  none 
  ; 
  I 
  think 
  the 
  others 
  proved 
  to 
  be 
  stung. 
  It 
  is 
  fairly 
  

   certain 
  that 
  this 
  larva 
  is 
  punctidactyla, 
  as 
  it 
  agrees 
  with 
  that 
  larva 
  

   in 
  the 
  very 
  clear 
  points 
  that 
  are 
  described 
  by 
  Hofmann 
  as 
  dis- 
  

   tinguishing 
  punctidactyla 
  from 
  that 
  of 
  cosmodactyla. 
  Indeed, 
  the 
  

   chief 
  use 
  of 
  this 
  specimen 
  is 
  to 
  enable 
  me 
  to 
  follow 
  what 
  

   Hofmann 
  says. 
  His 
  description 
  has 
  the 
  great 
  advantage 
  that 
  it 
  

   is 
  absolute, 
  and 
  enables 
  both 
  species 
  (cosmodactyla 
  and 
  punctidactyla) 
  

   to 
  be 
  distinguished, 
  whilst 
  Porritt's 
  (very 
  able 
  for 
  the 
  time 
  it 
  was 
  

   written) 
  is 
  of 
  little 
  use, 
  except 
  to 
  anyone 
  who 
  has 
  the 
  two 
  larvae 
  before 
  

   him 
  for 
  comparison, 
  the 
  more 
  so 
  since 
  the 
  most 
  definite 
  distinguishing 
  

   character 
  of 
  the 
  two 
  species, 
  which 
  he 
  found 
  in 
  his 
  specimens, 
  the 
  colouring 
  

   of 
  the 
  head 
  (see 
  p. 
  307), 
  does 
  not 
  appear 
  to 
  hold 
  good 
  generally, 
  either 
  

   according 
  to 
  Hofmann, 
  to 
  Mr. 
  Bankes' 
  observations 
  (antea, 
  p. 
  286), 
  or 
  in 
  

   my 
  own 
  more 
  limited 
  experience.] 
  The 
  most 
  notable 
  difference 
  is 
  in 
  

   the 
  secondary 
  hairs. 
  In 
  A. 
  punctidactyla 
  these 
  are 
  more 
  numerous, 
  more 
  

   generally 
  distributed, 
  and 
  rather 
  snorter. 
  They 
  are 
  less 
  various 
  in 
  

   length 
  ; 
  the 
  great 
  majority 
  of 
  them 
  are 
  about 
  0*08mm. 
  long. 
  In 
  

   A. 
  cosmodactyla 
  there 
  are 
  few 
  as 
  short 
  as 
  this, 
  the 
  majority 
  being 
  about 
  

   # 
  12mm. 
  In 
  both 
  there 
  are 
  longer 
  ones, 
  but 
  these 
  are 
  rarer 
  in 
  A. 
  

   punctidactyla, 
  and 
  only 
  occur 
  near 
  the 
  tubercles. 
  The 
  form 
  of 
  these 
  

   hairs 
  is 
  very 
  distinctive, 
  in 
  A. 
  cosmodactyla 
  they 
  taper 
  very 
  little, 
  and 
  

   then 
  swell 
  out 
  at 
  the 
  ends, 
  to 
  be 
  nearly 
  as 
  thick 
  there 
  as 
  they 
  are 
  at 
  

   their 
  bases, 
  with 
  bifid 
  or 
  multispiculate 
  ends. 
  In 
  A, 
  punctidactyla 
  they 
  

   have, 
  at 
  first 
  glance, 
  all 
  the 
  appearance 
  of 
  ordinary 
  hairs, 
  regularly 
  

   tapering, 
  and 
  with 
  sharp 
  points. 
  It 
  is 
  only 
  on 
  close 
  examination, 
  with 
  

   a 
  good 
  deal 
  of 
  magnification, 
  that 
  it 
  is 
  seen 
  that 
  they 
  are 
  more 
  or 
  less 
  

  

  