﻿THE 
  EARLY 
  STAGES 
  OF 
  WEST 
  AFRICAN 
  MOSQUITOS. 
  423 
  

  

  less 
  expanded, 
  composed 
  of 
  five 
  to 
  seven 
  subplumose 
  hairs. 
  The 
  rest 
  of 
  the 
  abdominal 
  

   setae 
  do 
  not 
  apparently 
  call 
  for 
  special 
  mention. 
  

  

  Diagnosis. 
  — 
  The 
  smaller 
  size 
  of 
  the 
  paddles 
  and 
  the 
  large 
  tufts 
  at 
  their 
  distal 
  

   ends 
  suffice 
  to 
  distinguish 
  this 
  pupa 
  from 
  those 
  of 
  other 
  known 
  species 
  of 
  Eretmopodites. 
  

  

  Habitat. 
  — 
  Accra, 
  26.vii.1921, 
  in 
  water 
  collected 
  in 
  disused 
  tins 
  near 
  the 
  European 
  

   Hospital. 
  

  

  Ficalbia 
  mediolineata, 
  Theo. 
  

  

  Larva. 
  — 
  The 
  length 
  of 
  the 
  larva 
  when 
  fully 
  grown 
  is 
  about 
  5 
  mm. 
  It 
  is 
  pale- 
  

   coloured, 
  with 
  a 
  bronze-brown 
  siphon 
  and 
  conspicuous 
  dark 
  lines 
  on 
  the 
  anterior 
  

   lateral 
  angles 
  of 
  the 
  thorax 
  due 
  to 
  the 
  coiled 
  respiratory 
  trumpets 
  of 
  the 
  pupa 
  which 
  

   show 
  through 
  the 
  larval 
  cuticle. 
  

  

  Head 
  (fig. 
  12) 
  broad, 
  length 
  nearly 
  0-8 
  mm. 
  and 
  greatest 
  breadth 
  about 
  0-9 
  mm. 
  

   Antennae 
  somewhat 
  similar 
  to 
  those 
  of 
  Mimomyia 
  hispida, 
  long, 
  slightly 
  curved, 
  

   not 
  at 
  all 
  infuscated, 
  bearing 
  at 
  about 
  the 
  middle 
  a 
  large 
  tuft 
  of 
  plumose 
  hairs, 
  and 
  

   covered 
  (especially 
  basally) 
  with 
  large 
  spicules. 
  The 
  pre-antennal 
  hairs 
  of 
  Lang 
  

   are 
  very 
  small 
  tufts, 
  the 
  outer 
  post-antennals 
  large 
  tufts 
  of 
  about 
  a 
  dozen 
  plumose 
  

   hairs, 
  the 
  inner 
  and 
  mid 
  post-antennals 
  longer 
  tufts 
  of 
  similar 
  plumose 
  hairs, 
  the 
  

   former 
  composed 
  of 
  five, 
  and 
  the 
  latter 
  of 
  three 
  hairs. 
  The 
  mental 
  plate 
  (fig. 
  12, 
  a) 
  

   is 
  small, 
  rather 
  flat, 
  with 
  a 
  large, 
  pointed, 
  central 
  tooth, 
  and 
  on 
  each 
  side 
  of 
  it 
  about 
  

   eight 
  smaller 
  teeth, 
  the 
  most 
  lateral 
  of 
  which 
  are 
  the 
  largest. 
  

  

  Thorax 
  broad 
  ; 
  lateral 
  tufts 
  long 
  and 
  composed 
  of 
  plumose 
  hairs, 
  those 
  on 
  the 
  

   middle 
  and 
  posterior 
  thirds 
  with 
  well 
  developed 
  basal 
  spines. 
  

  

  Abdomen 
  not 
  very 
  hairy. 
  Lateral 
  abdominal 
  setae 
  long 
  and 
  plumose 
  basally. 
  

   Comb 
  composed 
  of 
  about 
  twelve 
  small 
  fringed 
  spines 
  arranged 
  in 
  a 
  transverse 
  row. 
  

   Si 
  phonal 
  tuft 
  composed 
  of 
  two 
  or 
  three 
  rather 
  long 
  hairs, 
  subsiphonal 
  of 
  four 
  or 
  

   five 
  pubescent 
  hairs, 
  and 
  anal 
  of 
  about 
  four 
  more 
  delicate 
  branches. 
  The 
  siphon 
  

   has 
  a 
  narrow, 
  dark, 
  basal 
  band 
  ; 
  length 
  (about 
  1 
  -2 
  mm.) 
  eight 
  times 
  the 
  basal 
  dia- 
  

   meter 
  ; 
  hair-tuft, 
  composed 
  of 
  two 
  rather 
  long 
  simple 
  hairs, 
  situated 
  at 
  about 
  the 
  

   junction 
  of 
  the 
  middle 
  and 
  posterior 
  thirds 
  ; 
  apparently 
  without 
  pecten. 
  Anal 
  

   segment 
  highly 
  chitinised, 
  the 
  dorsal 
  side 
  of 
  the 
  chitinised 
  area 
  about 
  twice 
  as 
  long 
  

   as 
  the 
  ventral, 
  covered 
  dorsally 
  with 
  spicules 
  which 
  are 
  long 
  near 
  the 
  posterior 
  border 
  ; 
  

   on 
  each 
  side 
  near 
  the 
  middle 
  of 
  the 
  posterior 
  margin 
  is 
  a 
  long, 
  strong, 
  single 
  or 
  

   double 
  seta. 
  Beard 
  very 
  small 
  ; 
  dorsal 
  setae 
  well 
  developed, 
  three 
  or 
  four 
  above 
  

   and 
  below 
  on 
  each 
  side. 
  Anal 
  papillae 
  very 
  small 
  (length 
  about 
  0-15 
  mm.), 
  with 
  

   pointed 
  ends. 
  

  

  Pupa.— 
  The 
  pupa 
  is 
  about 
  4 
  mm. 
  long 
  when 
  extended. 
  When 
  alive 
  it 
  rests 
  at 
  

   the 
  surface 
  of 
  the 
  water 
  with 
  the 
  two 
  very 
  long 
  respiratory 
  trumpets 
  directed 
  

   forwards 
  and 
  either 
  submerged 
  with 
  the 
  long 
  dorsal 
  hairs 
  of 
  the 
  second 
  to 
  

   fourth 
  abdominal 
  segments 
  directed 
  upwards 
  and 
  forwards 
  and 
  just 
  reaching 
  the 
  

   surface 
  film, 
  or 
  with 
  the 
  cephalothorax 
  slightly 
  depressed, 
  a 
  fact 
  with 
  which 
  should 
  

   be 
  correlated 
  the 
  obsolete 
  condition 
  of 
  the 
  dendritic 
  tufts 
  on 
  the 
  first 
  abdominal 
  

   segment. 
  It 
  is 
  rather 
  top-heavy 
  owing 
  to 
  the 
  length 
  of 
  the 
  trumpets. 
  

  

  Cephalothorax. 
  Respiratory 
  trumpets 
  (fig. 
  13, 
  a) 
  straight, 
  very 
  long 
  and 
  narrow, 
  

   dark 
  brown, 
  except 
  the 
  extreme 
  base 
  and 
  the 
  apical 
  one-fifth 
  or 
  one-sixth, 
  which 
  

   is 
  white. 
  Length 
  about 
  2-7 
  mm., 
  breadth 
  in 
  the 
  middle 
  about 
  70 
  fi; 
  proximal 
  end 
  

   slightly 
  wider, 
  distal 
  extremity 
  with 
  a 
  narrow 
  neck 
  and 
  a 
  funnel-shaped 
  opening. 
  

   The 
  ratio 
  of 
  the 
  length 
  of 
  the 
  meatus 
  to 
  the 
  total 
  length 
  of 
  the 
  trumpet 
  is 
  about 
  

   1 
  to 
  1 
  • 
  1 
  . 
  The 
  cephalothoracic 
  setae 
  are 
  rather 
  poorly 
  developed 
  and 
  do 
  not 
  call 
  

   for 
  special 
  mention, 
  the 
  dorsal 
  setae 
  are 
  single 
  and 
  short. 
  

  

  Abdomen 
  (fig. 
  13, 
  b). 
  The 
  paddles 
  are 
  long 
  and 
  very 
  narrow, 
  length 
  about 
  0-9 
  mm., 
  

   greatest 
  breadth 
  about 
  0-15 
  mm., 
  ratio 
  6 
  to 
  1 
  . 
  The 
  midrib 
  is 
  well 
  developed, 
  but 
  the 
  

   external 
  buttress 
  is 
  practically 
  wanting 
  ; 
  there 
  are 
  no 
  terminal 
  setae, 
  and 
  the 
  

  

  (8455) 
  2G2 
  

  

  