﻿AGDISTIDES. 
  129 
  

  

  b. 
  On 
  certain 
  segments; 
  an 
  azygos 
  tubercle 
  on 
  prothorax 
  — 
  

   Herbertia 
  tamaricis. 
  

   II. 
  Hairs 
  setiform, 
  very 
  long. 
  

  

  1. 
  Tubercle 
  iv 
  level 
  with 
  spiraclef— 
  ? 
  satanas. 
  

  

  In 
  other 
  respects 
  Adactylus 
  bennetii 
  and 
  Herbertia 
  tamaricis 
  

   are 
  peculiarly 
  specialised, 
  e.g., 
  the 
  larvae 
  of 
  these 
  species 
  have 
  the 
  

   caudal 
  horn 
  single 
  ; 
  those 
  of 
  all 
  other 
  species 
  examined 
  have 
  it 
  

   double 
  ; 
  also, 
  H. 
  tamaricis 
  has 
  a 
  central 
  horn 
  on 
  the 
  prothorax, 
  a 
  

   development 
  found 
  in 
  the 
  larva 
  of 
  no 
  other 
  species. 
  Chapman, 
  

   who 
  made 
  a 
  special 
  study 
  of 
  the 
  Agdistid 
  larvae 
  at 
  Cannes 
  in 
  1897, 
  

   and 
  has 
  since 
  made 
  a 
  critical 
  examination 
  of 
  those 
  in 
  the 
  Walsing- 
  

   ham 
  collection, 
  has 
  given 
  us 
  considerable 
  detailed 
  information. 
  

   He 
  observes 
  that 
  the 
  larva 
  of 
  Agdistis 
  heydenii 
  is 
  very 
  warty, 
  and 
  

   shows 
  the 
  nature 
  of 
  the 
  tubercular 
  protuberances. 
  In 
  this 
  species, 
  on 
  

   the 
  meso- 
  and 
  metathorax 
  are 
  two 
  protuberances 
  (as 
  in 
  H. 
  tamaricis), 
  

   which 
  each 
  carry 
  two 
  hairs, 
  with 
  two 
  smaller 
  haired 
  processes 
  (? 
  iii 
  

   and 
  iv) 
  in 
  line 
  below 
  them 
  to 
  spiracular 
  level. 
  The 
  two 
  hairs 
  on 
  the 
  

   large 
  tubercles 
  are 
  situated 
  one 
  before 
  the 
  other, 
  pointed 
  backwards, 
  

   knobbed, 
  and 
  placed 
  on 
  transparent 
  globes 
  ; 
  the 
  abdominal 
  segments 
  

   have 
  regular 
  trapezoidal 
  tubercles 
  (i 
  and 
  ii) 
  with 
  hairs 
  directed 
  back- 
  

   wards, 
  on 
  opaline 
  globes 
  (which 
  contrast 
  with 
  the 
  terra- 
  cotta 
  colour 
  of 
  

   larva). 
  On 
  the 
  8th 
  and 
  9th 
  abdominals, 
  tubercles 
  ii 
  are 
  approximated 
  

   and 
  form 
  tall 
  horns, 
  which 
  are 
  quite 
  distinct 
  and 
  separate, 
  the 
  larva 
  

   thus 
  having 
  four 
  horns. 
  In 
  H. 
  tamaricis, 
  the 
  front 
  horns 
  (double) 
  

   remain 
  on 
  meso- 
  but 
  are 
  lost 
  on 
  metathorax 
  ; 
  i 
  and 
  ii 
  are 
  small 
  on 
  the 
  

   abdominal 
  segments, 
  and 
  approximated 
  except 
  on 
  2 
  and 
  5, 
  where 
  they 
  

   form 
  peculiar 
  processes 
  like 
  those 
  seen 
  on 
  some 
  Pyralid 
  pupa?, 
  e.g., 
  

   Botys 
  ruralis 
  (verticalis) 
  ; 
  on 
  the 
  8th 
  abdominal, 
  i 
  and 
  ii 
  are 
  more 
  

   pronounced, 
  forming 
  four 
  black 
  tubercles, 
  whilst, 
  on 
  the 
  9th, 
  they 
  form 
  

   a 
  horn 
  constricted 
  at 
  about 
  half 
  its 
  length, 
  after 
  a 
  swelling 
  which 
  

   represents 
  two 
  tubercles, 
  and 
  has 
  a 
  hair 
  at 
  each 
  side, 
  the 
  horn 
  has 
  a 
  

   second 
  pair 
  of 
  hairs 
  at 
  its 
  tip. 
  Each 
  of 
  the 
  two 
  tall 
  mesothoracic 
  

   horns 
  carries 
  three 
  tubercles, 
  slight 
  elevations 
  with 
  whitish 
  tips, 
  viz., 
  

   a 
  higher 
  anterior, 
  a 
  posterior, 
  and 
  a 
  lateral 
  one. 
  On 
  the 
  abdominal 
  

   segments, 
  iii 
  (immediately 
  above 
  spiracle), 
  iv 
  (a 
  good 
  way 
  behind 
  and 
  

   rather 
  below 
  spiracle), 
  and 
  v 
  (much 
  below 
  spiracle) 
  each 
  forms 
  a 
  small 
  

   white 
  point 
  (? 
  short 
  hair). 
  The 
  anal 
  segment 
  has 
  eight 
  longish 
  bristles. 
  

   In 
  the 
  larva 
  of 
  Adactylus 
  staticis 
  the 
  caudal 
  horn, 
  like 
  the 
  prothoracic, 
  

   is 
  double, 
  the 
  larva 
  being 
  otherwise 
  free 
  from 
  warts, 
  protuberances, 
  

   etc. 
  The 
  spiracles 
  of 
  H. 
  tamaricis 
  are 
  large 
  and 
  prominent, 
  especially 
  the 
  

   prothoracic 
  and 
  8th 
  abdominal, 
  which 
  are 
  set 
  on 
  small 
  yellow 
  knobs. 
  

  

  The 
  detailed 
  resemblance 
  exhibited 
  by 
  the 
  Agdistid 
  larvae 
  to 
  their 
  

   foodplant 
  for 
  protective 
  purposes 
  is 
  very 
  striking. 
  In 
  the 
  young 
  larva 
  

   of 
  Herbertia 
  tamaricis, 
  the 
  2nd 
  and 
  5th 
  abdominal 
  segments 
  are 
  brown, 
  

   and 
  the 
  mesothorax 
  partly 
  so, 
  the 
  rest 
  green 
  with 
  a 
  brown 
  dorsal 
  mark, 
  

   and 
  so 
  mimicking 
  the 
  tamarisk, 
  as 
  do 
  a 
  bug 
  and 
  a 
  Curculio 
  — 
  with 
  green 
  

   and 
  pink. 
  In 
  11. 
  tamaricis 
  the 
  brown 
  larva 
  has 
  usually 
  traces 
  of 
  a 
  

   reddish 
  or 
  orange 
  spiracular 
  band, 
  and, 
  occasionally, 
  a 
  fullfed 
  larva 
  

   retains 
  the 
  green 
  coloration, 
  reminding 
  one 
  very 
  much, 
  both 
  in 
  colour 
  

   and 
  protuberances, 
  of 
  the 
  larva 
  of 
  Geometra 
  papiUonaria 
  when 
  it 
  

   assumes 
  its 
  spring 
  clothing. 
  It 
  has 
  a, 
  yellowish-white 
  subspiraoular 
  

  

  i 
  Founded 
  on 
  a 
  single 
  larva 
  in 
  Lord 
  Walsingham's 
  colleotion, 
  possibly 
  

   satanas, 
  but 
  just 
  possibly 
  not 
  even 
  an 
  Agdistid 
  (Chapman). 
  

  

  