﻿HYBRIDISATION 
  IN 
  LEPIDOPTERA. 
  35 
  

  

  1897 
  (Ent. 
  Bee, 
  ix., 
  p. 
  320) 
  and 
  fertile 
  eggs 
  were 
  laid 
  September 
  4th, 
  which 
  

   hatched 
  September 
  18th-19th 
  ; 
  the 
  larvae 
  were 
  fullfed 
  in 
  November 
  and 
  early 
  

   December. 
  From 
  the 
  pupae, 
  imagines 
  emeiged 
  December 
  28th, 
  1897-January 
  

   27th, 
  1898 
  — 
  14 
  in 
  all 
  (11 
  <? 
  s 
  and 
  3 
  ? 
  s). 
  The 
  imagines 
  small, 
  pale 
  brownish-white 
  or 
  

   greyish-brown 
  in 
  colour, 
  with 
  some 
  ancestral 
  markings 
  more 
  or 
  less 
  defined 
  but 
  4 
  

   only 
  can 
  be 
  referred 
  to 
  a 
  distinct 
  form 
  (viz., 
  T. 
  crepuscularia). 
  Another 
  batch 
  of 
  

   eggs 
  laid 
  October 
  21st-22nd 
  produced 
  larvae 
  November 
  13th-14th, 
  but 
  the 
  larvae 
  

   died. 
  Of 
  the 
  14 
  inbred 
  T. 
  hybr. 
  mixta 
  four 
  were 
  paired, 
  one 
  ? 
  depositing 
  two, 
  the 
  

   other 
  six 
  eggs; 
  seven 
  of 
  these 
  hatched, 
  but 
  the 
  larvae 
  died 
  in 
  a 
  few 
  days. 
  

  

  In 
  one 
  case 
  a 
  $ 
  of 
  the 
  parent 
  race 
  was 
  crossed 
  with 
  a 
  2 
  hybrid, 
  

   and 
  the 
  cross 
  successfully 
  reared 
  to 
  the 
  imaginal 
  stage, 
  viz. 
  : 
  — 
  

  

  vi. 
  Hybrid 
  between 
  c? 
  T. 
  crepuscularia 
  x 
  ? 
  riding 
  i-suffusa. 
  — 
  The 
  parentage 
  

   being 
  S 
  T. 
  crepuscularia 
  (second 
  brood) 
  x 
  ? 
  ( 
  <? 
  C. 
  bistortata 
  x 
  ? 
  T. 
  ab. 
  

   delamerensis). 
  The 
  progeny 
  is, 
  therefore, 
  three-fourths 
  T. 
  crepuscularia 
  and 
  one- 
  

   fourth 
  T. 
  bistortata. 
  The 
  female 
  hybrid 
  chosen 
  for 
  this 
  experiment 
  was 
  of 
  the 
  

   delamerensis 
  form, 
  and 
  taken 
  from 
  Bacot's 
  batch 
  i. 
  Pairing 
  took 
  place 
  on 
  July 
  

   4th. 
  49 
  imagines 
  resulted 
  and 
  were 
  exhibited, 
  38 
  <? 
  s 
  and 
  11 
  ? 
  s. 
  These 
  emerged 
  

   during 
  September 
  and 
  October. 
  Only 
  2 
  ? 
  s 
  were 
  present 
  among 
  the 
  first 
  37 
  

   emergences, 
  and 
  9 
  among 
  the 
  last 
  12. 
  The 
  imagines 
  consisted 
  of 
  31 
  pale 
  and 
  18 
  dark 
  

   specimens. 
  With 
  the 
  exception 
  of 
  7 
  females 
  the 
  remainder 
  of 
  this 
  brood 
  are, 
  to 
  

   all 
  intents 
  and 
  purposes, 
  T. 
  crepuscularia. 
  Only 
  one 
  who 
  has 
  made 
  a 
  very 
  special 
  

   study 
  of 
  these 
  species 
  could 
  tell 
  that 
  the 
  latter 
  specimens 
  had 
  been 
  obtained 
  from 
  

   parents 
  that 
  had 
  been 
  crossed 
  with 
  T. 
  bistortata 
  = 
  T. 
  hybr. 
  reversa, 
  n. 
  hybr. 
  

  

  Cymatophorides. 
  — 
  The 
  Cymatophorids 
  give, 
  we 
  believe, 
  only 
  one 
  

   recorded 
  instance 
  of 
  hybridity, 
  viz. 
  : 
  — 
  

  

  Cymatophora 
  hybr. 
  fletcheri 
  (ocularis 
  $ 
  xor 
  % 
  ). 
  — 
  Fletcher 
  placed 
  

   in 
  a 
  sleeve 
  a 
  0. 
  ocularis 
  (octogesima) 
  $ 
  and 
  C. 
  or 
  2 
  , 
  in 
  June, 
  1893, 
  

   obtained 
  eggs 
  and 
  larvae 
  and 
  bred 
  33 
  2 
  moths 
  in 
  August 
  and 
  September 
  

   of 
  the 
  same 
  year. 
  The 
  progeny 
  resembled 
  0. 
  or, 
  except 
  that 
  both 
  orbicular 
  

   and 
  reniform 
  stigmata 
  were 
  very 
  conspicuous, 
  being 
  pure 
  white 
  filled 
  

   up 
  slightly 
  with 
  black, 
  whereas 
  in 
  C. 
  or 
  they 
  are 
  usually 
  inconspicuous 
  

   and 
  the 
  orbicular 
  sometimes 
  wanting. 
  None 
  of 
  the 
  pure 
  bred 
  0. 
  or 
  reared 
  

   at 
  the 
  same 
  time 
  has 
  the 
  stigmata 
  so 
  fully 
  developed 
  as 
  have 
  the 
  hybrids, 
  

   which 
  were 
  most 
  uniform 
  in 
  this 
  respect 
  (Ent. 
  Record, 
  iv., 
  p. 
  304). 
  

  

  Drepantjlides. 
  — 
  Hybrids 
  among 
  the 
  Drepanulids 
  are 
  exceedingly 
  

   rare. 
  We 
  can 
  only 
  trace 
  the 
  following 
  : 
  

  

  1. 
  Drepana 
  hybr. 
  rebeli 
  (curratula 
  $ 
  xfalcataria 
  2 
  )• 
  — 
  The 
  first 
  

   record 
  of 
  this 
  hybrid 
  appears 
  to 
  be 
  that 
  of 
  Gravenhorst 
  (his, 
  

   1834, 
  p. 
  720) 
  who 
  notes 
  that 
  a 
  pairing 
  of 
  Drepana 
  curratula 
  J 
  x 
  

   falcataria 
  2 
  produced 
  fertile 
  eggs, 
  larvae, 
  and 
  finally 
  2 
  imagines, 
  

   whilst 
  the 
  reciprocal 
  cross 
  produced 
  infertile 
  eggs 
  (see 
  also 
  Stett. 
  Ent. 
  

   Zeit... 
  1858, 
  pp. 
  231, 
  411). 
  The 
  same 
  crossing 
  was 
  made 
  by 
  Standfuss 
  

   in 
  1897, 
  and 
  imagines 
  reared 
  and 
  figured 
  (Entom., 
  1900, 
  pi. 
  viii., 
  figs. 
  

   5-6). 
  This 
  he 
  named 
  Drepana 
  hybr. 
  rebeli. 
  The 
  resultant 
  hybrid 
  imagines 
  

   paired 
  very 
  easily 
  and 
  the 
  females 
  laid 
  a 
  varying 
  number 
  of 
  eggs, 
  normal 
  

   to 
  outward 
  appearance, 
  in 
  which 
  embryos 
  formed, 
  but 
  no 
  larvae 
  hatched 
  

   therefrom, 
  the 
  shells, 
  when 
  opened, 
  being 
  found 
  to 
  contain 
  normally 
  

   developed, 
  but 
  dead, 
  caterpillars. 
  In 
  1898, 
  from 
  fresh 
  hybrid 
  crossings, 
  

   a 
  small 
  number 
  of 
  larvae 
  of 
  rebeli 
  J 
  x 
  rebeli 
  2 
  emerged 
  from 
  eggs, 
  the 
  

   larvae 
  full 
  of 
  life, 
  but 
  they 
  refused 
  food 
  ancl 
  died 
  within 
  IS 
  hours. 
  In 
  

   1898, 
  also, 
  the 
  reciprocal 
  hybrid 
  was 
  bred 
  by 
  Standfuss 
  {Entom.^ 
  1900, 
  

   pi. 
  viii., 
  tigs. 
  7-8). 
  

  

  2. 
  Dkkiwna 
  hybr. 
  approximati'ia 
  (falcataria 
  J 
  \curcatula 
  2 
  h 
  — 
  In 
  

   Standfuss' 
  D. 
  hybr. 
  rebeli 
  the 
  #s 
  and 
  9 
  s 
  emerged 
  together: 
  in 
  />. 
  

   hybr. 
  approximatula, 
  the 
  <S 
  s 
  soon 
  emerged 
  (autumn), 
  but 
  the 
  females 
  

   hybernated 
  as 
  pupae, 
  and 
  emerged 
  in 
  spring. 
  All 
  the 
  J 
  s 
  of 
  . 
  "pro.ci- 
  

  

  