﻿THE 
  BIONOMICS 
  OF 
  SOME 
  MALAYAN 
  ANOPHELINES. 
  

  

  143 
  

  

  thoracic 
  plumes 
  pressed 
  back 
  towards 
  the 
  tail 
  end 
  ; 
  their 
  caudal 
  tufts 
  directed 
  towards 
  

   the 
  head. 
  On 
  emergence 
  the 
  former 
  extend 
  themselves 
  at 
  right 
  angles, 
  suggesting 
  

   the 
  function 
  of 
  the 
  outriggers 
  of 
  a 
  catamaran, 
  which 
  function 
  they 
  probably 
  serve 
  ; 
  

   the 
  latter 
  extend 
  backwards. 
  

  

  Time 
  of 
  Oviposition. 
  

  

  This 
  was 
  noted 
  in 
  the 
  case 
  of 
  all 
  the 
  open-country 
  species 
  as 
  having 
  been, 
  as 
  a 
  

   rule, 
  between 
  8 
  p.m. 
  and 
  6 
  a.m. 
  But 
  there 
  were 
  a 
  few 
  exceptions. 
  Thus 
  an 
  A. 
  vagus 
  

   that 
  had 
  been 
  captured 
  on 
  14th 
  June 
  deposited 
  on 
  21st 
  between 
  12 
  midday 
  and 
  

   2 
  p.m. 
  106 
  ova. 
  Another 
  of 
  the 
  same 
  species, 
  taken 
  on 
  14th 
  June, 
  laid, 
  on 
  27th 
  of 
  

   the 
  month, 
  69 
  ova 
  between 
  8 
  and 
  10 
  a.m. 
  ; 
  a 
  third, 
  captured 
  on 
  1st 
  July, 
  laid 
  no 
  less 
  

   than 
  248 
  ova 
  between 
  2 
  and 
  4 
  p.m. 
  on 
  3rd 
  July 
  ; 
  and, 
  curiously 
  enough, 
  4 
  others, 
  

   out 
  of 
  7 
  females 
  of 
  this 
  species 
  placed 
  in 
  captivity 
  on 
  4th 
  July 
  with 
  a 
  view 
  to 
  obtaining 
  

   eggs, 
  oviposited 
  on 
  the 
  same 
  day, 
  all 
  between 
  8 
  a.m. 
  and 
  midday, 
  one 
  affording 
  a 
  

   batch 
  of 
  67 
  ova, 
  another 
  75 
  ova, 
  the 
  third 
  86 
  and 
  the 
  fourth 
  66. 
  Another 
  A. 
  vagus 
  

   laid 
  a 
  total 
  of 
  248 
  ova 
  between 
  2 
  and 
  4 
  p.m. 
  one 
  afternoon 
  ; 
  another 
  laid 
  a 
  batch 
  

   of 
  93 
  ova 
  during 
  the 
  night 
  of 
  3rd 
  August, 
  and 
  was 
  watched 
  ovipositing 
  in 
  the 
  afternoon 
  

   of 
  the 
  following 
  day, 
  between 
  2 
  and 
  4 
  p.m., 
  no 
  fewer 
  than 
  180 
  additional 
  ova 
  being 
  

   the 
  outcome. 
  An 
  A. 
  maculatus 
  was 
  seen 
  ovipositing 
  at 
  10 
  a.m. 
  on 
  12th 
  October, 
  

   56 
  ova 
  being 
  obtained 
  ; 
  and 
  another 
  of 
  the 
  same 
  species 
  laid 
  73 
  ova 
  at 
  about 
  3 
  p.m. 
  

   on 
  16th 
  October. 
  

  

  Length 
  of 
  Life-cycle. 
  

  

  This 
  was 
  found 
  to 
  vary 
  very 
  considerably, 
  even 
  in 
  the 
  case 
  of 
  larvae 
  bred 
  from 
  

   ova 
  laid 
  on 
  the 
  same 
  day 
  and 
  kept 
  under 
  the 
  same 
  conditions, 
  the 
  lack 
  of 
  uniformity 
  

   of 
  development 
  being 
  so 
  constant 
  as 
  to 
  make 
  it 
  difficult 
  to 
  arrive 
  at 
  any 
  precise 
  

   calculation 
  of 
  the 
  normal 
  length 
  of 
  the 
  cycle. 
  

  

  The 
  following 
  are 
  typical 
  data 
  obtained 
  from 
  bred 
  families 
  : 
  — 
  

  

  Species. 
  

  

  Number 
  

   of 
  Ova. 
  

  

  Date 
  of 
  

   Oviposition. 
  

  

  First 
  

   Offspring 
  

   Emerged. 
  

  

  Length 
  

  

  of 
  its 
  

  

  Life-Cycle. 
  

  

  Last 
  

   Offspring 
  

   Emerged. 
  

  

  Length 
  

  

  of 
  its 
  

  

  Life-Cycle. 
  

  

  Total 
  

   Offspring. 
  

  

  A 
  . 
  vagus 
  

  

  146 
  

  

  4.xii.20 
  

  

  14.xii.20 
  

  

  10 
  days 
  

  

  18.xii.20 
  

  

  14 
  days 
  

  

  75 
  

  

  A. 
  subpictusvax. 
  

  

  

  

  

  

  

  

  

  malayensis 
  

  

  114 
  

  

  6.xi.20 
  

  

  17.xi.20 
  

  

  11 
  days 
  

  

  22.xi.20 
  

  

  16 
  days 
  

  

  60 
  

  

  A 
  . 
  ludlowi 
  

  

  120 
  

  

  25.X.20 
  

  

  5.xi.20 
  

  

  10 
  days 
  

  

  9.xi.20 
  

  

  14 
  days 
  

  

  36 
  

  

  A 
  . 
  aconitus 
  

  

  91 
  

  

  ll.xii.20 
  

  

  29.xii.20 
  

  

  18 
  days 
  

  

  7.i.21 
  

  

  27 
  days 
  

  

  61 
  

  

  A 
  . 
  hyrcanus 
  . 
  . 
  

  

  117 
  

  

  13.xii.20 
  

  

  24.xii.20 
  

  

  11 
  days 
  

  

  30.xii.20 
  

  

  17 
  days 
  

  

  81 
  

  

  A 
  . 
  hyrcanus 
  var. 
  

  

  

  

  

  

  

  

  

  paeditaeniatus 
  

  

  147 
  

  

  7.ii.21 
  

  

  23.ii.21 
  

  

  16 
  days 
  

  

  2.iii.21 
  

  

  23 
  days 
  

  

  64 
  

  

  A. 
  barbirostris 
  

  

  159 
  

  

  12.xii.20 
  

  

  31.xii.20 
  

  

  19 
  days 
  

  

  12.L21 
  

  

  31 
  days 
  

  

  47 
  

  

  A 
  . 
  maculatus 
  . 
  . 
  

  

  123 
  

  

  17.xi.20 
  

  

  29.xi.20 
  

  

  12 
  days 
  

  

  4.xii.20 
  

  

  17 
  days 
  

  

  43 
  

  

  A 
  . 
  karwari 
  

  

  97 
  

  

  15.xii.20 
  

  

  29.xii.20 
  

  

  14 
  days 
  

  

  2.i.21 
  

  

  18 
  days 
  

  

  47 
  

  

  A 
  . 
  fuliginosus 
  

  

  46 
  

  

  22.i.21 
  

  

  6.H.21 
  

  

  14 
  days 
  

  

  13.ii.21 
  

  

  21 
  days 
  

  

  40 
  

  

  A. 
  kochi 
  

  

  110 
  

  

  8.X.20 
  

  

  19.X.20 
  

  

  11 
  days 
  

  

  24.X.20 
  

  

  16 
  days 
  

  

  84 
  

  

  A. 
  tessellatus 
  . 
  . 
  

  

  ? 
  

  

  27.xi.20 
  

  

  8.xii.20 
  

  

  10 
  days 
  

  

  ll.xii.20 
  

  

  13 
  days 
  

  

  29 
  

  

  Apart 
  from 
  any 
  irregularity 
  of 
  hatching, 
  differences 
  in 
  the 
  length 
  of 
  the 
  life-cycle 
  

   certainly 
  depend, 
  in 
  part 
  at 
  all 
  events, 
  on 
  inequality 
  in 
  the 
  rate 
  of 
  growth 
  of 
  the 
  larvae, 
  

   even 
  though 
  kept 
  under 
  similar 
  conditions. 
  Thus, 
  an 
  A. 
  vagus 
  laid, 
  on 
  14th 
  May, 
  

   45 
  ova 
  ; 
  on 
  20th 
  May 
  the 
  majority 
  of 
  the 
  larvae 
  were 
  found 
  to 
  measure 
  5 
  mm. 
  in 
  

   length, 
  and 
  were 
  considered 
  as 
  three-quarters 
  grown 
  ; 
  but 
  a 
  small 
  minority, 
  looking 
  

   as 
  if 
  they 
  had 
  only 
  recently 
  hatched, 
  were 
  barely 
  2 
  mm. 
  in 
  length. 
  A 
  second 
  family 
  

   of 
  A. 
  vagus 
  larvae, 
  all 
  from 
  ova 
  deposited 
  on 
  14th 
  May, 
  consisted, 
  on 
  the 
  20th 
  of 
  the 
  

  

  