﻿THE 
  BIONOMICS 
  OF 
  SOME 
  MALAYAN 
  ANOPHELINES. 
  145 
  

  

  which 
  the 
  ovum 
  from 
  which 
  it 
  sprang 
  had 
  been 
  laid 
  ; 
  the 
  third 
  larva 
  seemed 
  then 
  to 
  

   be 
  very 
  little 
  larger 
  than 
  when 
  first 
  seen. 
  

  

  The 
  phenomena 
  of 
  the 
  unequal 
  hatching 
  of 
  Anopheline 
  ova, 
  and 
  of 
  the 
  inequality 
  

   in 
  the 
  rate 
  of 
  development 
  of 
  the 
  larvae, 
  must 
  go 
  far 
  to 
  ensure 
  the 
  continuance 
  of 
  

   a 
  particular 
  strain. 
  Indeed, 
  some 
  such 
  provision 
  was 
  to 
  be 
  looked 
  for, 
  since 
  the 
  

   Anophelines 
  invariably 
  deposit 
  their 
  ova 
  in 
  large 
  numbers 
  all 
  at 
  once. 
  Were 
  the 
  

   offspring 
  to 
  emerge 
  with 
  equal 
  precision 
  the 
  chances 
  of 
  the 
  extirpation 
  of 
  the 
  race 
  

   either 
  by 
  natural 
  enemies 
  or 
  as 
  the 
  outcome 
  of 
  unfavourable 
  conditions 
  would 
  be 
  

   enormously 
  increased. 
  

  

  Effect 
  of 
  Removal 
  of 
  Larvae 
  and 
  Pupae 
  from 
  Water. 
  

  

  Larvae 
  removed 
  from 
  water 
  rapidly 
  succumbed 
  even 
  in 
  a 
  moist 
  atmosphere, 
  

   but 
  pupae 
  removed 
  on 
  blotting 
  paper 
  and 
  kept 
  in 
  a 
  thoroughly 
  moist 
  atmosphere 
  

   were 
  able 
  to 
  survive 
  and 
  complete 
  their 
  metamorphosis 
  within 
  the 
  usual 
  limits 
  

   of 
  time. 
  It 
  is 
  noteworthy, 
  as 
  affording 
  evidence 
  of 
  the 
  hardihood 
  of 
  Stegomyia 
  

   albopicta, 
  that 
  the 
  pupae 
  will 
  survive 
  for 
  hours, 
  even 
  when 
  thoroughly 
  dry. 
  On 
  

   one 
  occasion 
  a 
  pupa 
  thrown 
  on 
  a 
  dry 
  surface 
  in 
  the 
  very 
  early 
  morning 
  was 
  seen 
  

   at 
  3 
  p.m. 
  to 
  be 
  struggling 
  vigorously 
  when 
  attacked 
  by 
  small 
  ants. 
  

  

  Hours 
  of 
  Pupation. 
  

  

  In 
  the 
  very 
  great 
  majority 
  of 
  instances 
  pupation 
  took 
  place 
  during 
  the 
  night, 
  but 
  

   some 
  exceptions 
  were 
  met 
  with. 
  Thus 
  a 
  small 
  family 
  of 
  7 
  larvae 
  of 
  A. 
  vagus 
  all 
  

   pupated, 
  almost 
  simultaneously, 
  one 
  afternoon, 
  the 
  pupae 
  affording 
  3 
  males 
  and 
  

  

  4 
  females. 
  In 
  a 
  family 
  of 
  42 
  larvae 
  of 
  A. 
  subpictus 
  var. 
  malayensis 
  8 
  were 
  recorded 
  

   as 
  pupating 
  as 
  2 
  p.m., 
  7 
  at 
  3 
  p.m., 
  and 
  6 
  between 
  2 
  and 
  4 
  p.m. 
  In 
  a 
  family 
  of 
  36 
  

   larvae 
  of 
  A. 
  ludlowi, 
  21 
  pupated 
  at 
  about 
  4 
  p.m., 
  6 
  pupated 
  in 
  the 
  morning 
  (8 
  to 
  12), 
  

  

  1 
  at 
  10 
  a.m., 
  2 
  at 
  noon 
  ; 
  and 
  in 
  three 
  other 
  families 
  of 
  this 
  species 
  there 
  was 
  also 
  a 
  

   high 
  percentage 
  of 
  pupations 
  in 
  the 
  day 
  time. 
  Of 
  a 
  family 
  of 
  8 
  larvae 
  of 
  A. 
  karwari, 
  

  

  5 
  pupated 
  at 
  11 
  a.m. 
  In 
  a 
  family 
  of 
  20 
  larvae 
  of 
  A. 
  maculatus, 
  1 
  was 
  recorded 
  as 
  

   pupating 
  at 
  9 
  a.m., 
  11 
  between 
  9 
  a.m. 
  and 
  noon, 
  1 
  at 
  11 
  a.m., 
  2 
  at 
  11.50 
  a.m., 
  and 
  

  

  2 
  at 
  1 
  p.m. 
  Similar 
  data 
  were 
  obtained 
  in 
  the 
  case 
  of 
  A. 
  hyrcanus, 
  A. 
  barbirostris, 
  

   A. 
  fuliginosus, 
  A. 
  kochi, 
  and 
  A. 
  tessellatus. 
  In 
  the 
  case 
  of 
  Stegomyia 
  albopicta, 
  a 
  day 
  

   flier, 
  it 
  was 
  the 
  rule, 
  rather 
  than 
  the 
  exception, 
  for 
  pupation 
  to 
  take 
  place 
  by 
  day. 
  

  

  It 
  should 
  be 
  remarked 
  that 
  the 
  exceptional 
  pupations 
  were 
  not 
  precipitated 
  as 
  

   the 
  result 
  of 
  interference 
  with 
  larvae 
  resting 
  prior 
  to 
  pupation. 
  In 
  most 
  species 
  it 
  

   was 
  possible 
  to 
  infer 
  some 
  few 
  hours 
  beforehand 
  the 
  imminence 
  of 
  pupation 
  by 
  the 
  

   change 
  in 
  appearance 
  of 
  the 
  larvae 
  ; 
  in 
  the 
  Myzomyia 
  group, 
  in 
  particular, 
  there 
  is 
  

   a 
  deepening 
  of 
  shade 
  and 
  an 
  increase 
  in 
  the 
  apparent 
  density. 
  

  

  If 
  at 
  this 
  stage 
  the 
  larvae 
  were 
  suddenly 
  alarmed, 
  as 
  for 
  instance 
  by 
  transfer 
  to 
  

   other 
  water, 
  pupation 
  occurred 
  instantly, 
  the 
  pupa 
  scurrying 
  away 
  and 
  gradually 
  

   shedding 
  the 
  larval 
  skin. 
  This 
  would 
  seem 
  to 
  be 
  the 
  direct 
  result 
  of 
  strong 
  muscular 
  

   action, 
  the 
  larval 
  skin 
  being 
  already 
  distended 
  to 
  its 
  utmost 
  limit. 
  

  

  It 
  was 
  rather 
  astonishing 
  to 
  find 
  that 
  the 
  pupal 
  eye 
  is 
  at 
  once 
  functional. 
  The 
  

   pupae 
  of 
  a 
  large 
  number 
  of 
  A 
  . 
  kochi, 
  known 
  to 
  be 
  about 
  five 
  hours 
  old, 
  dived 
  simul- 
  

   taneously, 
  even 
  when 
  a 
  shadow 
  was 
  slowly 
  thrown 
  on 
  them 
  by 
  interposing 
  an 
  object 
  

   between 
  their 
  bowl 
  and 
  an 
  electric 
  light 
  at 
  some 
  little 
  distance 
  away. 
  This 
  was 
  noted 
  

   also 
  with 
  other 
  species. 
  

  

  Duration 
  of 
  Pupal 
  Stage. 
  

  

  Pupae 
  formed 
  during 
  one 
  night 
  usually 
  afforded 
  imagos 
  on 
  the 
  morning 
  but 
  one 
  

   following, 
  that 
  is 
  to 
  say, 
  within 
  36 
  to 
  48 
  hours. 
  No 
  instances 
  of 
  any 
  prolongation 
  of 
  

   the 
  pupal 
  period 
  were 
  ever 
  observed, 
  though 
  the 
  data 
  as 
  to 
  thousands 
  were 
  recorded. 
  

  

  (S750)' 
  k 
  

  

  