﻿THE 
  EARLY 
  STAGES 
  OF 
  WEST 
  AFRICAN 
  MOSQUITOS. 
  413 
  

  

  is 
  slightly 
  granular 
  or 
  shagreened. 
  The 
  terminal 
  processes 
  at 
  the 
  posterior 
  end 
  of 
  

   the 
  abdomen 
  bear 
  rather 
  stout 
  single 
  or 
  double 
  setae, 
  or 
  a 
  small 
  tuft 
  of 
  three 
  to 
  five 
  

   hairs. 
  The 
  dorsal 
  abdominal 
  setae 
  are 
  arranged 
  as 
  shown 
  in 
  the 
  figure 
  (fig. 
  3, 
  a) 
  and 
  

   therefore 
  mention 
  need 
  be 
  made 
  of 
  only 
  the 
  more 
  important 
  elements. 
  The 
  lateral 
  

   setae 
  (A) 
  are 
  extremely 
  long 
  (nearly 
  2 
  mm.) 
  and 
  strong 
  on 
  segments 
  i 
  to 
  vii 
  ; 
  they 
  

   are 
  single 
  and 
  pubescent 
  or 
  slightly 
  subplumose. 
  The 
  sublateral 
  setae 
  (B) 
  are 
  present 
  

   on 
  segments 
  ii 
  to 
  vii, 
  are 
  highly 
  developed, 
  very 
  long, 
  and 
  similar 
  to 
  the 
  setae 
  of 
  the 
  

   lateral 
  row. 
  The 
  submedian 
  setae 
  (C) 
  appear 
  to 
  be 
  present 
  only 
  on 
  segments 
  ii 
  to 
  v 
  

   and 
  are 
  situated 
  unusually 
  far 
  externally, 
  close 
  to 
  the 
  sublateral 
  setae 
  ; 
  they 
  are 
  

   similar 
  to 
  the 
  lateral 
  setae 
  on 
  segments 
  iii 
  to 
  v, 
  and 
  on 
  segment 
  ii 
  are 
  modified 
  into 
  

   strong 
  tufts 
  and 
  displaced 
  somewhat 
  inwards. 
  The 
  dendritic 
  tuft 
  on 
  segment 
  i 
  is 
  

   well 
  developed, 
  dark-coloured, 
  and 
  highly 
  branched. 
  The 
  ventral 
  abdominal 
  setae 
  

   are 
  all 
  small 
  or 
  relatively 
  small 
  and 
  do 
  not 
  require 
  special 
  description. 
  The 
  abdominal 
  

   stigmata 
  are 
  conspicuous. 
  

  

  Habitat. 
  — 
  Sekondi, 
  19. 
  vi. 
  1920 
  (E. 
  E. 
  Grey) 
  ; 
  Nsawam, 
  a 
  station 
  about 
  twenty-five 
  

   miles 
  north 
  of 
  Accra 
  and 
  on 
  the 
  fringe 
  of 
  the 
  thick 
  forest 
  zone, 
  24.vi.1920 
  ; 
  found 
  

   in 
  a 
  rot-hole 
  in 
  the 
  stump 
  of 
  a 
  large 
  silk-cotton 
  tree 
  (Eriodendron 
  anfractuosutn). 
  

  

  Uranotaenia 
  balfouri, 
  Theo. 
  

  

  Larva. 
  — 
  The 
  larva 
  of 
  this 
  species 
  was 
  described 
  by 
  Wesche 
  (Bull. 
  Ent. 
  Res. 
  i, 
  

   p. 
  50). 
  Having 
  recently 
  had 
  the 
  opportunity 
  of 
  examining 
  several 
  specimens 
  of 
  

   this 
  larva 
  at 
  higher 
  magnifications 
  than 
  those 
  employed 
  by 
  Wesche, 
  we 
  should 
  

   like 
  to 
  supplement 
  his 
  description 
  as 
  follows 
  : 
  — 
  The 
  larva 
  when 
  fully 
  grown 
  is 
  about 
  

   3 
  mm. 
  in 
  length, 
  the 
  head 
  is 
  elongated, 
  length 
  about 
  0-6 
  mm., 
  breadth 
  about 
  0-5 
  mm. 
  ; 
  

   the 
  antennae, 
  sparsely 
  clothed 
  with 
  spicules, 
  are 
  very 
  dark 
  brown 
  and 
  short, 
  length 
  

   about 
  • 
  14 
  mm., 
  bearing 
  in 
  place 
  of 
  a 
  hair-tuft 
  a 
  single 
  small 
  hair 
  a 
  little 
  before 
  the 
  

   middle. 
  The 
  pre-antennal 
  tuft 
  of 
  Lang 
  is 
  a 
  very 
  small 
  tuft 
  of 
  about 
  three 
  hairs 
  ; 
  

   the 
  outer 
  post-antennal 
  a 
  tuft 
  of 
  three, 
  four 
  or 
  more 
  longish 
  hairs, 
  and 
  the 
  inner 
  

   and 
  middle 
  post-antennals 
  are 
  stout 
  and 
  spine-like, 
  similar 
  to 
  those 
  of 
  U. 
  albo- 
  

   abdominalis. 
  The 
  mental 
  plate 
  is 
  small, 
  situated 
  unusually 
  far 
  anteriorly, 
  with 
  a 
  

   pointed 
  central 
  tooth 
  and 
  five 
  or 
  six 
  smaller 
  teeth 
  on 
  each 
  side 
  of 
  it. 
  

  

  Thorax 
  relatively 
  broad, 
  length 
  about 
  0-7 
  mm., 
  greatest 
  breadth 
  about 
  0-9 
  mm. 
  

   The 
  dorso-lateral 
  setae 
  composed 
  of 
  long, 
  subplumose 
  hairs 
  arising 
  from 
  small 
  

   chitinised 
  plates, 
  which 
  bear 
  also 
  — 
  especially 
  those 
  on 
  the 
  posterior 
  third 
  — 
  small 
  

   hook-like 
  spines. 
  On 
  each 
  side 
  of 
  the 
  dorsum, 
  in 
  a 
  sublateral 
  position,. 
  is 
  an 
  anterior 
  

   and 
  a 
  posterior 
  tuft, 
  the 
  latter 
  being 
  the 
  larger 
  and 
  composed 
  of 
  about 
  a 
  dozen 
  hairs. 
  

  

  Abdomen 
  bearing 
  long 
  lateral 
  setae 
  only 
  on 
  the 
  first 
  two 
  segments. 
  Eighth 
  

   segment 
  with 
  two 
  large 
  lateral 
  chitinous 
  plates 
  practically 
  enveloping 
  the 
  whole 
  

   segment, 
  and 
  a 
  second 
  pair 
  of 
  smaller 
  chitinous 
  plates 
  posteriorly 
  between 
  the 
  bases 
  

   of 
  the 
  siphon 
  and 
  the 
  anal 
  segment. 
  Comb 
  set 
  at 
  the 
  posterior 
  margin 
  of 
  the 
  large 
  

   lateral 
  chitinous 
  plate, 
  composed 
  of 
  five 
  to 
  eight 
  large, 
  pointed 
  spines 
  with 
  fringed 
  

   bases, 
  which 
  are 
  graded, 
  the 
  longest 
  being 
  the 
  third 
  from 
  the 
  ventral 
  end 
  of 
  the 
  row. 
  

   Wesche 
  figures 
  the 
  comb 
  but 
  shows 
  the 
  longest 
  spine 
  at 
  one 
  end 
  of 
  the 
  row. 
  The 
  

   siphonal, 
  subsiphonal 
  and 
  anal 
  tufts 
  are 
  well 
  developed 
  and 
  composed 
  of 
  about 
  

   six, 
  six., 
  and 
  twelve 
  hairs 
  respectively, 
  those 
  of 
  the 
  subsiphonal 
  tuft 
  being 
  sub- 
  

   plumose 
  and 
  the 
  others 
  simple. 
  The 
  tufts 
  situated 
  about 
  the 
  middle 
  of 
  the 
  siphon 
  

   are 
  composed 
  of 
  about 
  twelve 
  hairs. 
  The 
  pecten 
  extends 
  to 
  slightly 
  beyond 
  the 
  

   middle 
  of 
  the 
  siphon, 
  and 
  is 
  formed 
  of 
  about 
  nine 
  to 
  twelve 
  delicate, 
  fringed 
  scales 
  

   somewhat 
  similar 
  to 
  those 
  of 
  ■ 
  U. 
  alboabdominalis. 
  Anal 
  segment 
  completely 
  

   chitinised, 
  almost 
  twice 
  as 
  long 
  as 
  broad, 
  the 
  posterior 
  margin 
  fringed 
  with 
  small 
  

   spines 
  and 
  bearing 
  on 
  each 
  side 
  a 
  tuft 
  of 
  four 
  to 
  six 
  hairs. 
  Beard 
  poorly 
  developed. 
  

   Dorsal 
  setae 
  two 
  to 
  four 
  above 
  and 
  two 
  below 
  on 
  each 
  side 
  in 
  the 
  specimens 
  examined. 
  

   Anal 
  papillae 
  small, 
  subequal, 
  tapering 
  slight!}' 
  and 
  ending 
  in 
  blunt 
  points. 
  

  

  