﻿409 
  

  

  THE 
  EARLY 
  STAGES 
  OF 
  WEST 
  AFRICAN 
  MOSQUITOS.— 
  VI. 
  

  

  By 
  J. 
  W. 
  S. 
  Macfie 
  and 
  A. 
  Ingram, 
  

   West 
  African 
  Medical 
  Service. 
  

  

  

  In 
  this 
  paper 
  are 
  described 
  the 
  early 
  stages 
  of 
  a 
  few 
  more 
  West 
  African 
  mosquitos. 
  

   All 
  the 
  specimens 
  were 
  collected 
  in 
  the 
  Gold 
  Coast, 
  and 
  most 
  of 
  them 
  at 
  Accra 
  or 
  

   in 
  the 
  neighbourhood 
  of 
  that 
  town. 
  In 
  drawing 
  up 
  descriptions 
  of 
  larvae 
  we 
  have 
  

   followed 
  the 
  usual 
  plan, 
  but 
  in 
  the 
  case 
  of 
  the 
  setae 
  on 
  the 
  head 
  have 
  given, 
  when 
  

   necessary, 
  the 
  terms 
  employed 
  by 
  W. 
  D. 
  Lang 
  in 
  his 
  admirable 
  handbook 
  of 
  British 
  

   Mosquitos. 
  In 
  drawing 
  up 
  descriptions 
  of 
  pupae 
  we 
  have 
  used 
  the 
  terms 
  (and 
  

   lettering) 
  suggested 
  by 
  one 
  of 
  us 
  in 
  his 
  account 
  of 
  the 
  chaetotaxy 
  of 
  the 
  pupa 
  of 
  

   Stegomyia 
  fasciata 
  (Aedes 
  argenteus).* 
  We 
  have 
  once 
  more 
  to 
  express 
  our 
  

   indebtedness 
  to 
  Dr. 
  G. 
  A. 
  K. 
  Marshall, 
  of 
  the 
  Imperial 
  Bureau 
  of 
  Entomology, 
  

   and 
  to 
  Mr. 
  F. 
  W. 
  Edwards, 
  of 
  the 
  British 
  Museum, 
  for 
  help 
  and 
  advice 
  and 
  for 
  

   the 
  identification 
  of 
  species, 
  and 
  to 
  Mr. 
  A. 
  J. 
  Engel 
  Terzi 
  for 
  his 
  skilful 
  execution 
  

   of 
  the 
  figures. 
  

  

  Anopheles 
  nili, 
  Theo. 
  

  

  Larva. 
  — 
  The 
  larva 
  of 
  this 
  mosquito 
  has 
  not 
  yet 
  been 
  identified. 
  

  

  Pupa. 
  — 
  The 
  pupa 
  is 
  rather 
  small, 
  length 
  about 
  4 
  mm. 
  when 
  extended, 
  and 
  not 
  

   very 
  highly 
  chitinised. 
  Two 
  specimens 
  were 
  examined. 
  

  

  Cephahthorax. 
  The 
  respiratory 
  trumpets 
  resemble 
  those 
  of 
  A. 
  rufipes. 
  

  

  Abdomen 
  (fig. 
  1). 
  The 
  paddles, 
  which 
  are 
  about 
  0-65 
  mm. 
  long, 
  are 
  rather 
  

   narrow, 
  especially 
  at 
  their 
  bases, 
  the 
  ratio 
  of 
  length 
  to 
  greatest 
  breadth 
  being 
  about 
  

   1-9 
  to 
  1. 
  The 
  midrib 
  is 
  very 
  feebly 
  developed, 
  almost 
  absent 
  indeed, 
  and 
  the 
  

   external 
  buttress 
  is 
  ill-defined 
  but 
  appears 
  to 
  extend 
  beyond 
  the 
  middle 
  of 
  the 
  

   paddles. 
  At 
  the 
  distal 
  end 
  are 
  the 
  usual 
  two 
  hairs, 
  the 
  proximal 
  one 
  small, 
  straight, 
  

   single 
  or 
  double, 
  and 
  the 
  terminal 
  one 
  large, 
  stout, 
  shaped 
  like 
  a 
  boot-hook. 
  The 
  

   fringe 
  is 
  rather 
  long 
  and 
  very 
  delicate, 
  and 
  extends 
  round 
  almost 
  the 
  whole 
  paddle 
  

   except 
  only 
  for 
  a 
  short 
  distance 
  on 
  each 
  side 
  at 
  the 
  base. 
  

  

  Fig. 
  1. 
  Anopheles 
  nili, 
  Theo., 
  abdomen 
  of 
  pupa, 
  dorsal 
  view. 
  

  

  The 
  lateral 
  setae 
  (A) 
  at 
  the 
  posterior 
  angles 
  of 
  the 
  abdominal 
  segments 
  are 
  

   similar 
  to 
  those 
  of 
  A. 
  fimestus, 
  and 
  are 
  very 
  highly 
  chitinised 
  on 
  the 
  fourth 
  to 
  the 
  

   eight 
  segments. 
  On 
  segment 
  viii 
  the}' 
  are 
  long 
  stout 
  setae, 
  about 
  one 
  quarter 
  the 
  

   length 
  of 
  the 
  paddles, 
  which 
  give 
  off 
  numerous 
  branches 
  on 
  each 
  side 
  ; 
  on 
  segments 
  

   v, 
  vi, 
  and 
  vii 
  they 
  are 
  moderately 
  long, 
  strong, 
  slight!}' 
  curved 
  setae, 
  with 
  sharp 
  

  

  * 
  Bull. 
  Ent. 
  Res. 
  x, 
  p. 
  164. 
  

  

  