﻿GENERAL 
  BIOLOGICAL 
  CHARACTERS 
  OF 
  THE 
  ALUCITIDES. 
  103 
  

  

  not 
  present 
  in 
  the 
  newly-hatched 
  larva, 
  but 
  appears 
  in 
  the 
  second 
  

   instar 
  and 
  remains 
  throughout 
  larval 
  life, 
  often 
  undergoing 
  similar 
  

   development 
  to 
  the 
  primary. 
  

  

  In 
  addition 
  to 
  the 
  subprimary 
  tubercles, 
  there 
  are, 
  in 
  a 
  certain 
  

   section 
  of 
  the 
  plume 
  larvae, 
  accessory 
  tubercular 
  hairs, 
  that 
  are 
  to 
  be 
  

   found 
  (1) 
  Posterior 
  to 
  the 
  spiracles, 
  B 
  ± 
  and 
  B 
  2 
  , 
  (2) 
  Behind 
  the 
  dorsal 
  

   warts 
  of 
  the 
  meso- 
  and 
  metathorax. 
  These 
  are 
  certainly 
  not 
  present 
  

   in 
  the 
  first 
  instar, 
  and 
  not 
  always 
  developed 
  in 
  the 
  second, 
  but 
  are 
  to 
  

   be 
  found 
  in 
  the 
  third 
  or 
  fourth 
  instars 
  in 
  those 
  species 
  that 
  develop 
  

   them. 
  In 
  rank 
  they 
  are 
  inferior 
  to 
  the 
  subprimary 
  setae, 
  and 
  are, 
  when 
  

   developed, 
  easily 
  differentiated 
  from 
  the 
  scattered 
  secondary 
  skin-hairs, 
  

   for 
  they 
  are 
  usually 
  mounted 
  on 
  a 
  raised 
  skin 
  area, 
  after 
  the 
  manner 
  of 
  

   the 
  primary 
  and 
  subprimary 
  tubercular 
  setae, 
  and 
  like 
  these 
  may 
  be 
  

   developed 
  into 
  warts. 
  Occasionally 
  one 
  or 
  other 
  of 
  the 
  areas, 
  in 
  

   which 
  they 
  are 
  usually 
  developed, 
  gives 
  rise 
  to 
  a 
  small 
  group 
  of 
  little 
  

   hairs. 
  The 
  postspiracular 
  accessories 
  consist 
  of 
  two 
  groups— 
  (a) 
  On 
  

   the 
  flange, 
  slightly 
  lower 
  than 
  the 
  spiracle 
  in 
  level 
  = 
  B 
  1} 
  (b) 
  Kather 
  

   above 
  the 
  spiracle 
  in 
  level 
  — 
  B 
  2 
  . 
  In 
  some 
  species 
  the 
  upper 
  one 
  only 
  

   is 
  developed, 
  in 
  others, 
  only 
  the 
  lower, 
  whilst 
  a 
  number 
  of 
  species 
  

   have 
  both, 
  although 
  one 
  is 
  then 
  usually 
  weaker 
  than 
  the 
  other, 
  the 
  

   lower 
  being 
  usually 
  less 
  wart-like 
  than 
  the 
  upper. 
  

  

  The 
  modification 
  of 
  the 
  primary 
  and 
  secondary 
  tubercles 
  into 
  warts, 
  

   in 
  some 
  species, 
  is 
  very 
  remarkable. 
  From 
  the 
  simple 
  chitinous-based 
  

   seta 
  of 
  Platyptilia 
  yonodactyla, 
  to 
  the 
  many-haired 
  wart 
  of 
  Capperia 
  

   heterodactyla, 
  is 
  a 
  far 
  cry, 
  still 
  farther 
  to 
  that 
  of 
  the 
  beautiful 
  warts 
  of 
  

   Porrittia 
  yalactodactyla 
  and 
  Alucita 
  pentad 
  actyla. 
  There 
  can 
  be 
  no 
  

   doubt 
  that 
  there 
  is 
  a 
  close 
  connection 
  between 
  the 
  character 
  of 
  the 
  

   tubercles 
  and 
  the 
  environment, 
  and 
  that 
  whilst 
  the 
  internal-feeders 
  

   have 
  their 
  primary 
  and 
  secondary 
  tubercles 
  reduced 
  to 
  the 
  simplest 
  

   forms, 
  those 
  of 
  the 
  external-feeders, 
  varying, 
  however, 
  in 
  degree, 
  have 
  

   the 
  most 
  complicated 
  structures. 
  The 
  warts 
  are 
  essentially 
  formed 
  of 
  

   the 
  primary 
  spiculated 
  seta, 
  surrounded 
  by 
  a 
  number 
  of 
  short, 
  smooth, 
  

   bulbed 
  secondary 
  hairs," 
  very 
  similar 
  to 
  the 
  ordinary 
  surface-hairs. 
  

   The 
  peculiar 
  excrescences 
  in 
  Agdistid 
  larvae 
  are, 
  however, 
  somewhat 
  

   different 
  in 
  structure, 
  the 
  basal 
  area, 
  and 
  not 
  the 
  hairs 
  borne 
  thereon, 
  

   being 
  the 
  most 
  modified. 
  The 
  hornlike 
  processes 
  of 
  Adactylus 
  bennetii, 
  

   developed 
  on 
  the 
  prothorax 
  and 
  9th 
  abdominal 
  segment, 
  are 
  to 
  be 
  

   compared 
  carefully 
  with 
  those 
  of 
  the 
  other 
  Agdistid 
  larvae 
  (described 
  

   postea). 
  In 
  this 
  species 
  the 
  prothoracic 
  horns 
  are 
  extended 
  forward 
  

   over 
  the 
  head, 
  and 
  the 
  caudal 
  horn 
  rises 
  from 
  the 
  9th 
  abdominal 
  

   segment, 
  the 
  whole 
  ensemble 
  of 
  the 
  larva 
  being 
  that 
  of 
  a 
  miniature 
  

   Spbingid. 
  It 
  is 
  to 
  be 
  noted 
  that 
  the 
  caudal 
  horn 
  does 
  not 
  rise 
  from 
  the 
  

   8th 
  abdominal, 
  as 
  in 
  the 
  latter, 
  the 
  setae 
  of 
  i 
  and 
  ii 
  of 
  this 
  segment 
  

   being 
  in 
  front 
  of 
  the 
  horn, 
  and 
  in 
  their 
  correct 
  position 
  with 
  regard 
  to 
  

   the 
  spiracle. 
  

  

  In 
  the 
  Alucitid 
  larvsB, 
  the 
  primary 
  tubercular 
  hairs 
  are 
  usually 
  

  

  * 
  Somewhat 
  similar 
  hairs, 
  with 
  expanded 
  tips, 
  are 
  not 
  uncommon 
  in 
  other 
  

   superfamilies 
  of 
  lepidoptera. 
  Packard 
  states 
  (Bombycine 
  Moths 
  or 
  North 
  America, 
  

  

  p. 
  12) 
  that 
  the 
  Alncitid 
  larva 
  are 
  spiny, 
  and 
  their 
  peculiar 
  excretory 
  setfiB, 
  the 
  

   " 
  Driisenhiirchen 
  " 
  or 
  glandular 
  hairs 
  of 
  Zeller 
  (Linn. 
  F.tit., 
  vi., 
  p. 
  356) 
  are 
  similar, 
  

   as 
  Dimmock 
  has 
  observed, 
  to 
  the 
  glandular, 
  or 
  long, 
  hairs 
  of 
  plants 
  ; 
  Miss 
  Murtfeldt 
  

   adding 
  {PtycJw, 
  iii., 
  p. 
  390) 
  that 
  "there 
  is 
  a 
  very 
  close 
  imitation 
  in 
  the 
  dermal 
  

   clothing 
  of 
  the 
  larva) 
  of 
  Leioptilus 
  sericidactylus 
  to 
  that 
  of 
  the 
  young 
  leaves 
  of 
  

   Vernonia, 
  on 
  which 
  the 
  spring 
  and 
  early 
  summer 
  broods 
  teed." 
  

  

  