﻿THE 
  TABANIDAE 
  OF 
  SOUTHERN 
  NYAS 
  ALAND. 
  

  

  311 
  

  

  to 
  T. 
  secedens, 
  Walk. 
  If 
  the 
  former 
  is 
  the 
  case, 
  the 
  known 
  range 
  of 
  this 
  West 
  African 
  

   fly 
  will 
  have 
  be^n 
  very 
  greatly 
  extended, 
  for 
  on 
  the 
  eastern 
  side 
  of 
  Africa 
  it 
  has 
  hitherto 
  

   been 
  recorded 
  only 
  from 
  Uganda. 
  

  

  Tabanus 
  taeniola, 
  P. 
  de 
  B. 
  

  

  As 
  elsewhere 
  in 
  Tropical 
  Africa, 
  this 
  is 
  probably 
  the 
  commonest 
  species 
  of 
  the 
  

   genus 
  in 
  the 
  Mlanje 
  district, 
  and 
  though 
  most 
  numerous 
  from 
  October 
  onwards, 
  

   occasional 
  specimens 
  may 
  be 
  taken 
  as 
  late 
  as 
  April 
  and 
  May 
  at 
  the 
  end 
  of 
  the 
  rains. 
  

   There 
  is 
  also 
  reason 
  to 
  think 
  that 
  a 
  second 
  brood 
  of 
  this 
  species 
  may 
  hatch 
  about 
  

   May 
  in 
  some 
  parts 
  of 
  Nyasaland, 
  though 
  this 
  was 
  not 
  the 
  case 
  at 
  Mlanje 
  itself 
  during 
  

   the 
  year 
  of 
  my 
  visit. 
  The 
  only 
  flies 
  of 
  this 
  genus 
  found 
  on 
  the 
  top 
  of 
  the 
  plateau 
  

   on 
  Mt. 
  Mlanje, 
  at 
  an 
  elevation 
  of 
  6,500 
  feet, 
  seem 
  to 
  belong 
  to 
  this 
  species. 
  They 
  

   are 
  of 
  the 
  variatus 
  form, 
  but 
  are 
  considerably 
  and 
  uniformly 
  darker 
  than 
  normal 
  

   individuals. 
  Several 
  specimens 
  of 
  what 
  is 
  apparently 
  another 
  form 
  of 
  this 
  species 
  

   were 
  taken 
  in 
  November, 
  particularly 
  in 
  Portuguese 
  territory. 
  They 
  resemble 
  the 
  

   typical 
  form, 
  as 
  they 
  lack 
  any 
  of 
  the 
  median 
  dorsal 
  triangles 
  of 
  variatus, 
  but 
  are 
  very 
  

   much 
  smaller 
  and 
  very 
  dark 
  in 
  colour. 
  Some 
  examples 
  of 
  this 
  species 
  were 
  bred 
  

   from 
  larvae 
  collected 
  in 
  Portuguese 
  territory 
  to 
  the 
  east 
  of 
  Mt. 
  Mlanje 
  early 
  in 
  October. 
  

   As, 
  however, 
  the 
  larva 
  has 
  been 
  described 
  and 
  the 
  pupa 
  figured 
  by 
  Mr. 
  H. 
  H. 
  King 
  

   in 
  the 
  last 
  part 
  of 
  this 
  Bulletin 
  they 
  are 
  not 
  here 
  dealt 
  with 
  in 
  detail. 
  The 
  larva 
  

   is 
  chiefly 
  remarkable 
  for 
  its 
  very 
  white 
  colour 
  and 
  lack 
  of 
  pigment, 
  and 
  for 
  the 
  presence 
  

   of 
  a 
  row 
  of 
  bristles 
  immediately 
  anterior 
  to 
  the 
  anus. 
  It 
  is 
  one 
  of 
  the 
  most 
  active 
  

   and 
  restless 
  species 
  I 
  have 
  had 
  to 
  deal 
  with. 
  

  

  Tabanus 
  ustus, 
  Walk. 
  

  

  This 
  species 
  is 
  not 
  very 
  common 
  near 
  the 
  forested 
  parts 
  of 
  the 
  Mlanje 
  district, 
  

   but 
  on 
  the 
  plains 
  in 
  Portuguese 
  territory 
  to 
  the 
  east, 
  both 
  sexes 
  occurred 
  in 
  vast 
  

   numbers 
  in 
  October 
  ; 
  the 
  males 
  were 
  then 
  in 
  the 
  majority, 
  the 
  converse 
  being 
  the 
  case 
  

  

  Fig. 
  21. 
  Tabanus 
  ustus, 
  Walk. 
  ; 
  (a) 
  pupal 
  aster 
  of 
  <£, 
  X 
  35 
  ; 
  (a 
  1 
  ) 
  dorso-lateral 
  

   comb 
  of 
  <£, 
  X 
  70 
  ; 
  (b) 
  dorso-lateral 
  comb 
  of 
  $, 
  X 
  70. 
  

  

  about 
  a 
  month 
  later. 
  Plate 
  xxxi, 
  fig. 
  1, 
  shows 
  a 
  pool 
  in 
  a 
  nearly 
  dry 
  stream 
  bed, 
  

   around 
  which 
  enormous 
  numbers 
  of 
  freshly 
  hatched 
  males 
  of 
  this 
  species 
  occurred 
  

   at 
  the 
  beginning 
  of 
  October. 
  One 
  male 
  and 
  three 
  females 
  were 
  bred 
  in 
  the 
  laboratory 
  

  

  