﻿PLATYPTILIA 
  G0N0DACTYLA. 
  205 
  

  

  at 
  this 
  time 
  practically 
  fullfed 
  and 
  appeared 
  to 
  vary 
  in 
  a 
  much 
  less 
  degree 
  

   than 
  those 
  of 
  the 
  spring 
  brood, 
  being, 
  as 
  a 
  whole, 
  much 
  paler 
  ; 
  there 
  were 
  

   now 
  no 
  traces 
  of 
  mining, 
  all 
  the 
  feeding 
  being 
  done 
  outside, 
  and 
  one 
  larva 
  

   had 
  already 
  pupated 
  in 
  a 
  web 
  on 
  the 
  underside 
  of 
  a 
  leaf. 
  Pupation 
  

   took 
  place 
  between 
  this 
  date 
  and 
  August 
  26th, 
  by 
  which 
  time, 
  many 
  of 
  

   the 
  plants 
  looked 
  as 
  if 
  they 
  had 
  been 
  riddled, 
  for 
  the 
  growth 
  of 
  the 
  young 
  

   leaves 
  causes 
  the 
  upper 
  epidermis, 
  which 
  the 
  larvae 
  appear 
  to 
  leave 
  

   uneaten, 
  to 
  crack 
  (Tutt). 
  On 
  June 
  17th, 
  1904, 
  the 
  young 
  larvae, 
  a 
  day 
  or 
  

   two 
  old, 
  were 
  found 
  mining 
  in 
  the 
  substance 
  of 
  a 
  colt's-foot 
  leaf. 
  No 
  

   sign 
  of 
  their 
  work 
  was 
  visible 
  above 
  (on 
  June 
  20th), 
  except 
  a 
  faint 
  dis- 
  

   coloration 
  over 
  some 
  of 
  the 
  largest 
  ; 
  below, 
  nothing 
  is 
  to 
  be 
  seen 
  until 
  

   close 
  observation 
  shows 
  the 
  minute 
  hole 
  of 
  entry, 
  sometimes, 
  quite 
  

   close 
  to 
  the 
  eggshell, 
  at 
  others 
  so 
  far 
  from 
  an 
  eggshell 
  that 
  the 
  larva 
  must 
  

   have 
  travelled 
  some 
  distance 
  ; 
  by 
  holding 
  the 
  leaf 
  against 
  the 
  light, 
  the 
  

   little 
  larvae 
  and 
  their 
  mines 
  are 
  very 
  evident, 
  and 
  it 
  is 
  by 
  first 
  finding 
  

   the 
  mines 
  in 
  this 
  way 
  that 
  the 
  other 
  indications 
  just 
  noted 
  are 
  dis- 
  

   covered. 
  By 
  July 
  2nd, 
  the 
  larvae 
  are 
  still 
  mining 
  in 
  the 
  leaves, 
  eating 
  

   out 
  the 
  parenchyma, 
  and 
  leaving 
  the 
  upper 
  and 
  lower 
  layers 
  ; 
  they 
  are 
  

   ready, 
  however, 
  if 
  the 
  cover 
  fails 
  them, 
  to 
  use 
  a 
  little 
  silk, 
  or, 
  if 
  the 
  

   leaf 
  gets 
  dry 
  or 
  stale, 
  to 
  come 
  out 
  and 
  seek 
  other 
  quarters. 
  The 
  larvae 
  

   are 
  already 
  (some 
  of 
  them) 
  in 
  the 
  3rd 
  skin, 
  and 
  look, 
  inform 
  and 
  colouring, 
  

   much 
  like 
  the 
  full-fed 
  larva. 
  The 
  plants 
  on 
  which 
  they 
  were 
  placed 
  

   were 
  badly 
  established, 
  and 
  the 
  leaves 
  failing, 
  the 
  larvae 
  had 
  to 
  make 
  

   various 
  pilgrimages 
  ; 
  whether 
  in 
  consequence 
  of 
  this, 
  or 
  as 
  an 
  ordinary 
  and 
  

   natural 
  habit, 
  is 
  uncertain 
  ; 
  I 
  find 
  all 
  the 
  leaf-stalks 
  have 
  one 
  or 
  more 
  

   larvae 
  in 
  them, 
  as 
  evidenced 
  by 
  the 
  small 
  extrusion 
  of 
  frass 
  (Chapman). 
  

   (2) 
  Winter-feeding 
  larvae. 
  — 
  Little 
  is 
  known 
  of 
  the 
  habits 
  of 
  the 
  winter- 
  

   feeding 
  larvae, 
  from 
  the 
  time 
  they 
  hatch 
  in 
  September 
  until 
  the 
  earliest 
  

   days 
  of 
  April, 
  when 
  they 
  are 
  about 
  2-5mm. 
  in 
  length, 
  i.e., 
  the 
  second 
  

   (and 
  most 
  probably 
  the 
  hybernating) 
  instar, 
  at 
  which 
  time 
  they 
  may 
  be 
  

   found 
  in 
  the 
  hollow 
  scapes 
  of 
  Tussilago 
  farfara, 
  often 
  in 
  the 
  lower 
  

   part, 
  often 
  in 
  the 
  solid 
  basal 
  part, 
  and 
  sometimes 
  even 
  extending 
  into 
  

   the 
  rootstock. 
  That 
  little, 
  however, 
  is 
  important, 
  and 
  consists 
  of 
  an 
  

   observation 
  made 
  by 
  Ovenden, 
  in 
  October, 
  1903, 
  that 
  the 
  tiny 
  larvae 
  

   mine 
  in 
  the 
  leaves, 
  near 
  the 
  midrib 
  and 
  close 
  to 
  the 
  petiole, 
  along 
  which 
  

   he 
  suggests 
  the 
  larvae 
  bore 
  in 
  the 
  autumn, 
  and 
  at 
  the 
  base 
  of 
  which 
  they 
  

   lie 
  dormant 
  until 
  January 
  or 
  February, 
  when 
  they 
  enter 
  the 
  already 
  

   rapidly-growing 
  plant. 
  We 
  suspect 
  that 
  the 
  larva 
  enters 
  the 
  upper 
  part 
  of 
  

   the 
  rootstock 
  to 
  make 
  its 
  hybernaculum, 
  for 
  it 
  clearly 
  attacks 
  the 
  young 
  

   shoots 
  and 
  scape 
  just 
  as 
  they 
  are 
  springing 
  therefrom. 
  The 
  scape 
  of 
  T. 
  

   farfara 
  is, 
  when 
  well-grown, 
  hollow 
  from 
  the 
  base 
  of 
  the 
  receptacle 
  (carry- 
  

   ing 
  the 
  capitulum) 
  to 
  within 
  an 
  inch 
  or 
  so 
  of 
  the 
  point 
  where 
  it 
  leaves 
  the 
  

   rootstock. 
  Ovenden 
  writes 
  : 
  " 
  After 
  the 
  examination 
  of 
  some 
  dozens 
  

   of 
  flowering 
  stems 
  of 
  Tussilqc/o 
  farfara, 
  I 
  have 
  come 
  to 
  the 
  conclusion 
  

   that 
  the 
  larva 
  works 
  into 
  the 
  flowering-stem 
  when 
  very 
  minute. 
  I 
  

   found 
  some 
  yesterday 
  (April 
  20th, 
  1904), 
  no 
  longer 
  than 
  from 
  3mm.- 
  

   4mm., 
  low 
  down 
  in 
  the 
  stem, 
  in 
  fact 
  nearly 
  into 
  the 
  root, 
  whilst, 
  in 
  main- 
  

   plants, 
  the 
  entrance 
  holes 
  were 
  plainly 
  discernible 
  under 
  the 
  leaf-like 
  

   bracts 
  that 
  encircle 
  the 
  flowering-stalk. 
  I 
  found 
  the 
  large 
  ones 
  higher 
  

   up 
  the 
  stem, 
  and, 
  when 
  they 
  were 
  just 
  beneath 
  the 
  capitulum 
  they 
  appeared 
  

   to 
  be 
  mostly 
  in 
  their 
  last 
  instar. 
  There 
  were 
  plenty 
  of 
  traces 
  of 
  eating, 
  as 
  

   well 
  as 
  of 
  frass, 
  in 
  the 
  stem, 
  and, 
  as 
  there 
  was 
  not 
  a 
  single 
  Larva 
  observed 
  

   in 
  the 
  flower-head 
  itself, 
  although 
  the 
  bases 
  o( 
  the 
  capitula 
  sometimes 
  

  

  