﻿THE 
  EARLY 
  STAGES 
  OF 
  WEST 
  AFRICAN 
  MOSQUITOS. 
  429 
  

  

  Diagnosis. 
  — 
  The 
  pupae 
  of 
  Aedes 
  {0.) 
  irritans 
  and 
  Aedes 
  (0.) 
  wellmani 
  fall 
  into 
  

   the 
  group 
  in 
  our 
  provisional 
  key 
  (Bull. 
  Ent. 
  Res. 
  viii, 
  pp. 
  81-82) 
  which 
  includes 
  

   A. 
  (0.) 
  apicoannulatus 
  and 
  A. 
  (0.) 
  simulans. 
  Bacot's 
  figure 
  of 
  A. 
  (0.) 
  apicoannu- 
  

   latus 
  does 
  not 
  show 
  any 
  features 
  which 
  would 
  distinguish 
  this 
  species 
  from 
  A. 
  (0.) 
  

   irritans, 
  since 
  both 
  have 
  long 
  (about 
  0-2 
  mm.) 
  terminal 
  setae 
  on 
  the 
  paddles 
  and 
  a 
  

   fringe 
  composed 
  of 
  " 
  excessively 
  minute 
  and 
  delicate 
  " 
  serrations, 
  but 
  specimens 
  

   in 
  our 
  collection 
  show 
  the 
  following 
  differences 
  : 
  the 
  dorsum 
  of 
  the 
  cephalothorax 
  

   and 
  the 
  respiratory 
  trumpets 
  are 
  more 
  deeply 
  infuscated 
  ; 
  the 
  respiratory 
  trumpets 
  

   are 
  larger, 
  length 
  about 
  0-48 
  mm., 
  and 
  the 
  ratio 
  of 
  the 
  length 
  of 
  the 
  meatus 
  to 
  the 
  

   total 
  length 
  is 
  about 
  1 
  to 
  1 
  • 
  4 
  ; 
  the 
  cephalothoracic 
  setae 
  are 
  larger, 
  the 
  dorsal 
  setae 
  

   being 
  large 
  tufts 
  of 
  two 
  to 
  five 
  hairs 
  almost 
  as 
  long 
  as 
  the 
  trumpets 
  ; 
  the 
  fringe 
  of 
  

   denticulations 
  on 
  the 
  paddles 
  is 
  more 
  pronounced 
  ; 
  and 
  the 
  abdominal 
  setae 
  are 
  

   more 
  highly 
  developed, 
  the 
  sublateral 
  setae 
  on 
  segments 
  iv 
  to 
  vi 
  reaching 
  fully 
  or 
  

   almost 
  fully 
  across 
  the 
  two 
  following 
  segments. 
  The 
  terminal 
  setae 
  on 
  the 
  paddles 
  

   of 
  A. 
  (0.) 
  wellmani 
  might 
  serve 
  to 
  separate 
  this 
  species 
  from 
  the 
  other 
  three, 
  since 
  

   they 
  are 
  relatively 
  short 
  (about 
  0-1 
  mm.) 
  and 
  single. 
  A. 
  (0.) 
  simulans, 
  as 
  figured 
  

   by 
  Bacot, 
  has 
  the 
  terminal 
  seta 
  on 
  the 
  paddles 
  bifid, 
  no 
  fringe 
  and 
  the 
  lateral 
  setae 
  

   on 
  segment 
  vii 
  not 
  differentiated 
  as 
  tufts 
  ; 
  but 
  the 
  first 
  character 
  may 
  be 
  variable 
  

   (as 
  it 
  is 
  in 
  some 
  other 
  species), 
  and 
  as 
  regards 
  the 
  other 
  two 
  the 
  figures 
  may 
  be 
  mis- 
  

   leading 
  owing 
  to 
  the 
  relatively 
  low 
  magnification 
  at 
  which 
  they 
  are 
  drawn. 
  Bacot's 
  

   figures 
  are 
  not 
  sufficiently 
  detailed 
  to 
  show 
  the 
  sublateral 
  and 
  submedian 
  setae, 
  

   which 
  may 
  furnish 
  additional, 
  and 
  perhaps 
  more 
  satisfactory, 
  differential 
  points. 
  

  

  Habitat. 
  — 
  Aburi, 
  from 
  the 
  hollow 
  in 
  the 
  stem 
  of 
  a 
  cut 
  bamboo, 
  6.vi.l920. 
  

  

  Aedes 
  (Finlaya) 
  longipalpis, 
  Griinb. 
  

  

  Wesche 
  (Bull. 
  Ent. 
  Res. 
  i. 
  pp. 
  29-30) 
  described 
  the 
  larva 
  of 
  this 
  mosquito 
  under 
  

   the 
  name 
  Stcgomyia 
  pollinctor, 
  Graham, 
  but 
  he 
  had 
  at 
  his 
  disposal 
  only 
  a 
  single 
  

   damaged 
  specimen, 
  and, 
  as 
  noted 
  by 
  Edwards, 
  the 
  description 
  given 
  is 
  insufficient 
  

   for 
  identification. 
  Edwards 
  states 
  also 
  that 
  " 
  the 
  specimens 
  in 
  the 
  British 
  Museum 
  

   are 
  too 
  damaged 
  for 
  purposes 
  of 
  tabulation." 
  As 
  we 
  have 
  in 
  our 
  possession 
  a 
  larva 
  

   and 
  a 
  larval 
  pelt 
  of 
  this 
  species, 
  it 
  may 
  be 
  advisable 
  to 
  describe 
  them 
  here. 
  

  

  Larva. 
  — 
  The 
  larva 
  measures 
  about 
  5 
  mm. 
  to 
  6 
  mm. 
  in 
  length 
  when 
  fully 
  grown, 
  

   and 
  has 
  a 
  very 
  dark 
  brown 
  head 
  and 
  siphon. 
  

  

  Head 
  (fig. 
  16) 
  highly 
  chitinised 
  and 
  very 
  dark 
  brown; 
  length 
  about 
  0-8 
  mm., 
  

   greatest 
  breadth 
  about 
  1 
  • 
  1 
  mm. 
  Antennae 
  dark 
  brown, 
  cylindrical, 
  short 
  (about 
  

   0-3 
  mm.), 
  bearing 
  a 
  double 
  hair 
  in 
  place 
  of 
  a 
  tuft, 
  and 
  sparsely 
  clothed 
  with 
  small 
  

   spicules. 
  Hairs 
  relatively 
  poorly 
  developed 
  ; 
  the 
  pre-antennal 
  apparently 
  a 
  very 
  

   small 
  tuft 
  of 
  about 
  four 
  hairs, 
  the 
  outer 
  post-antennal 
  a 
  double 
  or 
  triple 
  hair, 
  and 
  

   the 
  mid 
  and 
  inner 
  post-antennals 
  rather 
  long 
  single 
  hairs. 
  Mental 
  plate 
  (fig. 
  16, 
  a) 
  

   with 
  a 
  large, 
  pointed, 
  central 
  tooth, 
  and 
  on 
  each 
  side 
  of 
  it 
  about 
  sixteen 
  smaller 
  

   teeth, 
  which 
  increase 
  in 
  size 
  and 
  are 
  more 
  widely 
  separated 
  towards 
  the 
  lateral 
  

   margin. 
  

  

  Thorax 
  slightly 
  wider 
  than 
  the 
  head 
  ; 
  lateral 
  hair-tufts 
  moderately 
  well 
  developed 
  

   and 
  without 
  definite 
  spine-like 
  processes 
  at 
  their 
  bases. 
  

  

  Abdomen 
  not 
  very 
  hairy. 
  Dorso-lateral 
  hairs 
  well 
  developed 
  on 
  the 
  first 
  two 
  

   segments 
  only. 
  Siphonal 
  (fig. 
  16) 
  and 
  anal 
  tufts 
  small, 
  composed 
  of 
  about 
  five 
  

   delicate, 
  apparently 
  simple, 
  hairs 
  ; 
  subsiphonal 
  tuft 
  larger, 
  composed 
  of 
  about 
  five 
  

   plumose 
  hairs. 
  Comb 
  a 
  roughly 
  triangular 
  patch 
  of 
  very 
  numerous 
  ( 
  ? 
  about 
  100) 
  

   small 
  fringed 
  scales. 
  Siphon 
  very 
  dark 
  brown, 
  tapering 
  distally 
  and 
  slightly 
  con- 
  

   stricted 
  at 
  its 
  base 
  ; 
  length 
  about 
  four 
  times 
  the 
  basal 
  diameter. 
  Pecten 
  a 
  row 
  of 
  

   about 
  seventeen 
  long 
  pointed 
  spines 
  with 
  small 
  basal 
  barbs, 
  reaching 
  to 
  about 
  the 
  

   middle 
  of 
  the 
  siphon, 
  without 
  detached 
  spines. 
  Hair-tuft 
  composed 
  of 
  about 
  eight 
  

   delicate 
  hairs, 
  situated 
  a 
  little 
  beyond 
  the 
  end 
  of 
  the 
  pecten. 
  Anal 
  segment 
  slightly 
  

  

  