﻿268 
  

  

  A. 
  ROEBUCK. 
  

  

  Emergence 
  of 
  the 
  adults 
  began 
  on 
  4th 
  May 
  and 
  finished 
  on 
  14th 
  May, 
  the 
  pupae 
  

   being 
  in 
  pots 
  of 
  soil 
  undisturbed 
  from 
  the 
  previous 
  July 
  but 
  occasionally 
  watered. 
  

   All 
  the 
  specimens 
  died 
  within 
  24 
  hours 
  of 
  emergence 
  except 
  a 
  female 
  Dolerus, 
  and 
  this 
  

   oviposited 
  on 
  a 
  young 
  wheat 
  plant. 
  As 
  the 
  imagines 
  were 
  removed 
  to 
  separate 
  

   chambers 
  after 
  emergence 
  and 
  no 
  two 
  were 
  ever 
  allowed 
  together, 
  the 
  eggs 
  were 
  

   produced 
  parthenogenetically. 
  

  

  This 
  female 
  exhibited 
  no 
  great 
  interest 
  in 
  life 
  during 
  the 
  first 
  few 
  days, 
  but 
  

   squatted 
  about 
  on 
  the 
  young 
  leaf 
  and 
  moved 
  its 
  position 
  a 
  few 
  times 
  a 
  day. 
  On 
  the 
  

   ninth 
  day 
  (23rd 
  May), 
  from 
  3 
  to 
  5 
  p.m. 
  on 
  a 
  bright 
  afternoon, 
  the 
  insect 
  exhibited 
  

   signs 
  of 
  excitement, 
  running 
  along 
  the 
  edges 
  of 
  the 
  leaves 
  with 
  the 
  antennae 
  violently 
  

   quivering. 
  After 
  inspecting 
  a 
  number 
  of 
  leaves 
  she 
  began 
  the 
  work 
  of 
  oviposition. 
  

   She 
  took 
  up 
  a 
  position 
  facing 
  the 
  stem 
  of 
  the 
  plant, 
  and 
  after 
  feeling 
  for 
  the 
  edge 
  of 
  the 
  

   leaf 
  inserted 
  the 
  " 
  saws 
  " 
  and 
  made 
  about 
  a 
  dozen 
  quick 
  movements 
  of 
  the 
  abdomen. 
  

   Then 
  followed 
  a 
  short 
  pause, 
  presumably 
  to 
  deposit 
  the 
  egg, 
  after 
  which 
  the 
  point 
  of 
  

   the 
  abdomen 
  was 
  lifted 
  from 
  the 
  surface 
  of 
  the 
  leaf. 
  The 
  whole 
  operation 
  took 
  about 
  

   half 
  a 
  minute, 
  and 
  after 
  a 
  few 
  minutes 
  pause 
  she 
  moved 
  further 
  along 
  the 
  leaf 
  and 
  

   repeated 
  the 
  process. 
  The 
  following 
  day 
  this 
  female 
  died. 
  There 
  was 
  nothing 
  to 
  

   indicate 
  the 
  presence 
  of 
  eggs 
  on 
  the 
  leaves, 
  and 
  at 
  first 
  it 
  seemed 
  doubtful 
  whether 
  any 
  

   could 
  have 
  been 
  laid. 
  During 
  the 
  next 
  few 
  days 
  the 
  eggs 
  began 
  to 
  enlarge, 
  and 
  the 
  

   swellings 
  along 
  the 
  margin 
  of 
  the 
  leaves 
  showed 
  exactly 
  the 
  purpose 
  of 
  the 
  sawing 
  and 
  

   the 
  number 
  of 
  eggs 
  laid 
  (fig. 
  2). 
  In 
  all, 
  64 
  eggs 
  were 
  deposited 
  by 
  this 
  insect. 
  The 
  

  

  Fig. 
  2. 
  Wheat 
  leaf 
  with 
  swellings 
  containing 
  eggs 
  of 
  Dolerus. 
  

  

  leaf 
  was 
  cut 
  along 
  the 
  margin 
  for 
  about 
  1 
  mm., 
  severing 
  the 
  upper 
  and 
  lower 
  

   epidermises. 
  Both 
  sides 
  of 
  the 
  leaves 
  were 
  used, 
  and 
  the 
  spacing 
  was 
  quite 
  irregular. 
  

   Fifteen 
  was 
  the 
  highest 
  number 
  of 
  eggs 
  on 
  anyone 
  leaf, 
  and 
  only 
  a 
  single 
  egg 
  occurred 
  

   on 
  several 
  leaves. 
  

  

  The 
  young 
  larvae 
  hatched 
  on 
  the 
  third 
  and 
  fourth 
  days 
  (26th 
  and 
  27th 
  May) 
  

   the 
  eggs 
  by 
  then 
  being 
  1 
  -5 
  mm. 
  long, 
  the 
  cavity 
  2 
  mm., 
  and 
  the 
  height 
  of 
  the 
  swelling 
  

   1 
  mm. 
  In 
  all 
  cases 
  the 
  head 
  end 
  of 
  the 
  larva 
  was 
  down 
  the 
  leaf 
  or 
  towards 
  the 
  stem 
  

   (fig. 
  3). 
  

  

  Fig. 
  3. 
  

  

  Leaf 
  rendered 
  transparent 
  to 
  show 
  position 
  of 
  egg 
  and 
  the 
  larva 
  within 
  it 
  ; 
  the 
  margin 
  

   of 
  the 
  leaf 
  is 
  cut 
  from 
  A 
  to 
  B 
  by 
  the 
  9- 
  

  

  