﻿226 
  

  

  BRITISH 
  LEPIDOPTERA. 
  

  

  follows 
  : 
  (1) 
  " 
  The 
  palpi 
  are 
  decidedly 
  longer" 
  (Sang, 
  Ent. 
  Mo. 
  Mag., 
  

   xviii., 
  p. 
  144). 
  - 
  South 
  has 
  carefully 
  examined 
  the 
  palpi 
  of 
  both, 
  and 
  

   " 
  quite 
  failed 
  to 
  see 
  any 
  perceptible 
  difference 
  in 
  their 
  respective 
  lengths." 
  

   (2) 
  "The 
  top 
  of 
  the 
  outer 
  digit 
  is 
  rendered 
  more 
  acute 
  by 
  the 
  deeper 
  

   concavity 
  of 
  the 
  hind 
  margin 
  of 
  that 
  digit" 
  (Sang, 
  loc. 
  cit.). 
  — 
  South 
  

   says 
  that 
  " 
  the 
  top 
  of 
  the 
  outer 
  digit 
  is, 
  in 
  bertrami, 
  variable 
  as 
  regards 
  

   its 
  structure; 
  in 
  some 
  specimens, 
  the 
  hind 
  margin 
  of 
  the 
  outer 
  digit 
  is 
  

   strongly 
  emarginate, 
  and 
  the 
  tip 
  is, 
  in 
  consequence, 
  produced 
  and 
  very 
  

   acute." 
  (3) 
  " 
  The 
  tibiae 
  in 
  dichrodactyla 
  are 
  brown 
  at 
  the 
  middle 
  and 
  

   apex, 
  and 
  there 
  is 
  a 
  brown 
  spot 
  at 
  the 
  end 
  of 
  the 
  first 
  tarsal 
  joint 
  " 
  

   (Stainton, 
  Ent. 
  Mo. 
  Mag., 
  ii., 
  p. 
  138). 
  — 
  South 
  says, 
  " 
  Identical 
  mark- 
  

   ings 
  exist 
  on 
  the 
  hindlegs 
  of 
  fresh 
  examples 
  of 
  bertrami." 
  As 
  noted 
  

   above, 
  the 
  genitalia 
  prove 
  the 
  absolute 
  distinctness 
  of 
  the 
  species, 
  and 
  

   it 
  would, 
  therefore, 
  be 
  purposeless 
  to 
  deal 
  with 
  Hering's 
  long 
  summar- 
  

   ised 
  article 
  (Stett. 
  Ent. 
  Zeit., 
  liii., 
  pp. 
  269-279), 
  attempting 
  to 
  prove 
  

   their 
  specific 
  unity, 
  and, 
  since 
  Fernald 
  has 
  discovered 
  in 
  Zeller's 
  own 
  

   examples, 
  sent 
  to 
  him 
  as 
  paUidactyla 
  {bertrami), 
  specimens 
  of 
  ochro- 
  

   dactyla, 
  the 
  statement 
  of 
  Zeller 
  that 
  he 
  had 
  bred 
  both 
  paUidactyla 
  and 
  

   ochrodactyla 
  from 
  Tanacetum 
  loses 
  all 
  force, 
  the 
  assumed 
  paUidactyla 
  

   being 
  probably 
  ochrodactyla 
  like 
  the 
  others 
  from 
  the 
  same 
  pabulum. 
  

  

  Egglaying. 
  — 
  The 
  $ 
  oviposits 
  at 
  night, 
  most 
  usually 
  quite 
  after 
  

   dark, 
  with 
  its 
  abdomen 
  thrust 
  down 
  among 
  the 
  disc 
  florets 
  of 
  the 
  tansy- 
  

   flowers; 
  one 
  egg 
  will, 
  probably, 
  be 
  laid 
  on 
  each 
  flower 
  (Sang). 
  

  

  Habits 
  of 
  larva. 
  — 
  The 
  young 
  larva 
  mines 
  down 
  the 
  flower- 
  stem 
  

   into 
  the 
  root 
  of 
  Tanacetum 
  vulgare 
  in 
  early 
  autumn, 
  where 
  it 
  remains 
  

   during 
  the 
  winter 
  and 
  until 
  the 
  fresh 
  shoots 
  are 
  thrown 
  up 
  in 
  the 
  

   following 
  spring, 
  working 
  up 
  these 
  as 
  the 
  plant 
  grows, 
  throwing 
  out 
  

   frass 
  from 
  the 
  joints 
  and 
  causing 
  the 
  whole 
  plant 
  to 
  droop, 
  very 
  like 
  

   the 
  effects 
  produced 
  by 
  the 
  larvae 
  of 
  Exaeretia 
  allisella 
  in 
  the 
  stems 
  of 
  

   Artemisia 
  vulgaris, 
  and 
  becoming 
  fullfed 
  about 
  the 
  end 
  of 
  June 
  (Sang). 
  

   The 
  mouth 
  of 
  the 
  mine 
  is 
  generally 
  between 
  the 
  axil 
  of 
  a 
  leaf 
  and 
  the 
  

   stem, 
  with 
  a 
  few 
  silk 
  threads 
  spun 
  from 
  one 
  to 
  the 
  other, 
  just 
  above 
  it, 
  

   among 
  which 
  the 
  dark 
  olive 
  or 
  blackish 
  frass 
  becomes 
  entangled, 
  as 
  

   the 
  larva 
  pushes 
  it 
  out 
  from 
  time 
  to 
  time 
  in 
  its 
  course 
  head 
  down- 
  

   ward; 
  the 
  quantity 
  then 
  increases 
  more 
  and 
  more, 
  until, 
  at 
  length, 
  the 
  

   accumulation 
  becomes 
  very 
  conspicuous, 
  and 
  betrays 
  the 
  presence 
  of 
  

   the 
  larva. 
  In 
  confinement, 
  as 
  soon 
  as 
  the 
  food 
  began 
  to 
  wither, 
  fresh 
  

   sprays 
  of 
  tansy 
  were 
  provided 
  for 
  the 
  larvae, 
  which, 
  as 
  often 
  as 
  this 
  

   occurred, 
  readily 
  left 
  the 
  old 
  stems 
  to 
  commence 
  mining 
  into 
  the 
  

   fresh 
  ones 
  (Buckler). 
  The 
  larva 
  bores 
  into 
  the 
  stem 
  at 
  the 
  axils 
  of 
  

   the 
  upper 
  leaves, 
  and 
  its 
  presence 
  may 
  be 
  detected 
  by 
  the 
  frass 
  extruded 
  

   from 
  the 
  point 
  of 
  entry 
  (South). 
  The 
  dull 
  whitish-green 
  larvae 
  throw 
  

   out 
  the 
  excrement 
  from 
  the 
  joints 
  of 
  the 
  leaves 
  and 
  this 
  indicates 
  their 
  

   presence 
  (Jeffrey). 
  The 
  feeding-habits 
  of 
  the 
  larvae 
  of 
  this 
  species 
  and 
  

   those 
  of 
  G. 
  paUidactyla 
  are 
  very 
  similar, 
  neither 
  species 
  seeming 
  to 
  do 
  

   at 
  all 
  well 
  in 
  small 
  stems. 
  The 
  stems 
  in 
  which 
  the 
  larvae 
  of 
  G. 
  ochrodac- 
  

   tyla 
  arrived, 
  on 
  June 
  13th, 
  1904 
  (having 
  been 
  sent 
  originally 
  from 
  Dur- 
  

   ham), 
  were 
  from 
  # 
  25in. 
  to 
  *33in. 
  thick, 
  whereas 
  the 
  stems 
  of 
  the 
  variety 
  

   growing 
  in 
  my 
  garden 
  were 
  only 
  about 
  -22m. 
  in 
  thickness, 
  and, 
  in 
  these 
  

   smaller 
  stems,the 
  larvae 
  did 
  not 
  seem 
  at 
  allhappy 
  nor 
  progress 
  satisfactorily 
  

   (Bacot, 
  June 
  26th, 
  1904). 
  The 
  following 
  are 
  actual 
  dates 
  on 
  which 
  

   larvae 
  have 
  been 
  found 
  — 
  July 
  20th, 
  1861, 
  in 
  the 
  shoots 
  of 
  Tanacetum 
  

   vulgare, 
  at 
  Wiesbaden, 
  but 
  in 
  early 
  June 
  in 
  1866 
  (Rossler) 
  ; 
  mid- 
  June, 
  

  

  