﻿161 
  

  

  THE 
  CHAETOTAXY 
  OF 
  THE 
  PUPA 
  OF 
  STEGOMYIA 
  FASCIATA. 
  

  

  By 
  J. 
  W. 
  S.Macfie, 
  M.A, 
  D.Sc, 
  

  

  West 
  African 
  Medical 
  Service. 
  

  

  The 
  pupa 
  of 
  Stegomyia 
  fasciata 
  is 
  furnished 
  with 
  200 
  setae, 
  100 
  on 
  each 
  side, 
  

   which 
  may 
  be 
  conveniently 
  described 
  according 
  to 
  their 
  situations 
  as 
  follows 
  : 
  — 
  ■ 
  

   Cephalo-thoracic 
  setae, 
  

  

  Circum-ocular 
  . 
  . 
  . 
  . 
  . 
  . 
  . 
  . 
  . 
  . 
  3 
  

  

  Antero-thoracic 
  

   Dorsal 
  

  

  Supra-alar 
  . 
  . 
  

   Postero-thoracic 
  

  

  4 
  

   1 
  

   1 
  

   3 
  

  

  Abdominal 
  setae, 
  

  

  Dorsal 
  (including 
  the 
  lateral 
  setae 
  and 
  the 
  setae 
  on 
  

   the 
  paddles) 
  . 
  . 
  . 
  . 
  . 
  . 
  . 
  . 
  61 
  

  

  Ventral 
  27 
  

  

  100 
  on 
  each 
  side. 
  

  

  The 
  pupa 
  is 
  bilaterally 
  symmetrical, 
  that 
  is, 
  setae 
  occur 
  in 
  similar 
  situations 
  on 
  

   each 
  side 
  of 
  the 
  body, 
  so 
  that 
  it 
  will 
  suffice 
  to 
  describe 
  the 
  arrangement 
  on 
  one 
  side 
  

   only. 
  The 
  setae 
  on 
  the 
  two 
  sides 
  of 
  the 
  same 
  pupa, 
  however, 
  often 
  vary 
  as 
  regards 
  

   their 
  sub 
  -divisions, 
  and 
  similar 
  variations 
  occur 
  between 
  different 
  individuals 
  ; 
  

   as 
  an 
  example, 
  in 
  Table 
  I 
  are 
  shown 
  some 
  of 
  the 
  variations 
  that 
  were 
  found 
  in 
  ten 
  

   pupae 
  taken 
  at 
  random. 
  An 
  examination 
  of 
  a 
  larger 
  number 
  would 
  have 
  revealed 
  

   a 
  wider 
  range. 
  As 
  a 
  rule, 
  a 
  seta 
  which 
  is 
  sometimes 
  single, 
  sometimes 
  divided, 
  

   is 
  longer 
  when 
  single. 
  For 
  example, 
  in 
  one 
  pupa 
  the 
  seta 
  at 
  the 
  posterior 
  angle 
  of 
  

  

  Table 
  I. 
  

   Cephalo-thoracic 
  Setae, 
  showing 
  the 
  Variations 
  found 
  in 
  ten 
  Pupae. 
  

  

  Seta. 
  

  

  1 
  

  

  2 
  

  

  3 
  

  

  4 
  

  

  5 
  

  

  6 
  

  

  7 
  

  

  8 
  

  

  9 
  

  

  10 
  

  

  Circum-ocular, 
  Superior 
  

  

  1 
  - 
  

  

  1 
  2 
  

  

  - 
  1 
  

  

  1 
  1 
  

  

  1 
  2 
  

  

  1 
  1 
  

  

  1 
  1 
  

  

  1 
  1 
  

  

  1 
  1 
  

  

  1 
  1 
  

  

  Posterior 
  

  

  2 
  2 
  

  

  2 
  1 
  

  

  - 
  2 
  

  

  - 
  2 
  

  

  1 
  1 
  

  

  2 
  2 
  

  

  - 
  2 
  

  

  2 
  - 
  

  

  2 
  2 
  

  

  2 
  2 
  

  

  Inferior 
  

  

  1 
  1 
  

  

  3 
  1 
  

  

  - 
  1 
  

  

  1 
  - 
  

  

  1 
  1 
  

  

  - 
  1 
  

  

  1 
  1 
  

  

  1 
  1 
  

  

  1 
  1 
  

  

  1 
  2 
  

  

  Antero-thoracic, 
  Anterior 
  

  

  3 
  2 
  

  

  2 
  3 
  

  

  3 
  2 
  

  

  - 
  2 
  

  

  2 
  - 
  

  

  2 
  2 
  

  

  2 
  2 
  

  

  3 
  2 
  

  

  2 
  2 
  

  

  3 
  3 
  

  

  Superior 
  

  

  1 
  2 
  

  

  2 
  1 
  

  

  1 
  1 
  

  

  - 
  1 
  

  

  2 
  - 
  

  

  2 
  2 
  

  

  2 
  2 
  

  

  3 
  3 
  

  

  2 
  2 
  

  

  2 
  2 
  

  

  Antero-inferior 
  

  

  1 
  1 
  

  

  1 
  1 
  

  

  1 
  1 
  

  

  - 
  1 
  

  

  1 
  - 
  

  

  1 
  1 
  

  

  1 
  1 
  

  

  1 
  1 
  

  

  1 
  1 
  

  

  1 
  I 
  

  

  Postero-inferior 
  

  

  1 
  1 
  

  

  1 
  2 
  

  

  1 
  1 
  

  

  - 
  2 
  

  

  1 
  - 
  

  

  2 
  2 
  

  

  2 
  2 
  

  

  - 
  2 
  

  

  2 
  2 
  

  

  1 
  2 
  

  

  Dorsal 
  

  

  1 
  1 
  

  

  2 
  2 
  

  

  2 
  - 
  

  

  3 
  2 
  

  

  2 
  2 
  

  

  2 
  2 
  

  

  2 
  2 
  

  

  2 
  1 
  

  

  2 
  1 
  

  

  3 
  2 
  

  

  Supra-alar 
  

  

  - 
  1 
  

  

  1 
  1 
  

  

  1 
  - 
  

  

  1 
  - 
  

  

  - 
  1 
  

  

  1 
  1 
  

  

  1 
  1 
  

  

  1 
  1 
  

  

  1 
  1 
  

  

  1 
  1 
  

  

  Postero-thoracic, 
  Internal 
  

  

  2 
  2 
  

  

  2 
  2 
  

  

  2 
  2 
  

  

  2 
  2 
  

  

  1 
  1 
  

  

  2 
  2 
  

  

  2 
  2 
  

  

  2 
  3 
  

  

  2 
  2 
  

  

  2 
  1 
  

  

  Median 
  

  

  1 
  1 
  

  

  1 
  1 
  

  

  1 
  1 
  

  

  1 
  1 
  

  

  1 
  1 
  

  

  1 
  1 
  

  

  1 
  1 
  

  

  1 
  1 
  

  

  1 
  1 
  

  

  I 
  1 
  

  

  External 
  

  

  2 
  2 
  

  

  1 
  1 
  

  

  1 
  1 
  

  

  1 
  1 
  

  

  1 
  1 
  

  

  1 
  2 
  

  

  2 
  1 
  

  

  1 
  1 
  

  

  1 
  1 
  

  

  1 
  1 
  

  

  (605) 
  

  

  f2 
  

  

  