﻿TSETSE 
  FLY 
  IN 
  SOUTHERN 
  RHODESIA, 
  1918. 
  79 
  

  

  with 
  the 
  forest 
  during 
  the 
  wet 
  season. 
  They 
  appear 
  to 
  graze 
  on 
  its 
  outskirts 
  with 
  

   impunity 
  in 
  the 
  winter. 
  No 
  specimens 
  of 
  tsetse 
  have 
  as 
  yet 
  been 
  taken 
  within 
  the 
  

   Rhodesian 
  border 
  in 
  this 
  region, 
  and 
  the 
  flies 
  in 
  1917 
  were 
  present 
  only 
  in 
  small 
  

   numbers 
  in 
  the 
  neighbourhood 
  of 
  the 
  border 
  on 
  the 
  Mocambique 
  side. 
  On 
  the 
  other 
  

   hand 
  the 
  losses 
  in 
  cattle 
  have 
  been 
  severe 
  in 
  some 
  cases, 
  as 
  many 
  as 
  eighty-six 
  head 
  

   during 
  the 
  past 
  season. 
  There 
  is 
  thus 
  reason 
  to 
  think 
  that 
  in 
  Melsetter, 
  as 
  elsewhere, 
  

   some 
  agency 
  other 
  than 
  tsetse 
  may 
  serve 
  to 
  transmit 
  the 
  infection 
  from 
  an 
  infected 
  

   beast 
  to 
  others 
  herded 
  in 
  its 
  vicinity. 
  

  

  The 
  situation 
  in 
  the 
  Melsetter 
  district 
  is 
  probably 
  unique 
  in 
  its 
  way, 
  constituting 
  

   an 
  instance 
  where 
  a 
  very 
  considerable 
  degree 
  of 
  settlement 
  and 
  development 
  lies 
  

   immediately 
  adjacent 
  to 
  practically 
  primitive 
  conditions 
  across 
  a 
  boundary 
  which 
  

   is 
  both 
  political 
  and 
  natural. 
  

  

  Breeding 
  Haunts 
  Of 
  Glossina 
  morsitans. 
  

  

  Very 
  little 
  work 
  has 
  been 
  carried 
  out 
  in 
  this 
  connection, 
  the 
  only 
  area 
  searched 
  

   for 
  pupae 
  since 
  the 
  writer's 
  previous 
  work 
  on 
  this 
  subject 
  being 
  Sipani 
  Vlei, 
  lying 
  

   east 
  of 
  the 
  Sengwe 
  River 
  and 
  north-west 
  of 
  Gokwe 
  in 
  the 
  Sebungwe 
  district. 
  This 
  

   Vlei 
  is 
  intensely 
  infested 
  with 
  fly 
  late 
  in 
  the 
  dry 
  season 
  and 
  bears 
  clumps 
  of 
  evergreen 
  

   trees 
  on 
  termite 
  mounds, 
  as 
  in 
  the 
  case 
  of 
  Manzituba 
  Vlei, 
  which 
  has 
  already 
  been 
  

   described.* 
  In 
  one 
  hollow 
  tree 
  alone 
  some 
  forty 
  live 
  pupae 
  were 
  secured 
  and 
  

   several 
  hundreds 
  of 
  empty 
  pupa-cases, 
  constituting 
  probably 
  a 
  record 
  for 
  any 
  

   single 
  location. 
  Pupae 
  could 
  be 
  found 
  by 
  searching 
  in 
  almost 
  any 
  sheltered 
  

   situation 
  at 
  the 
  bases 
  of 
  the 
  evergreen 
  trees 
  . 
  near 
  the 
  Vlei 
  and 
  a 
  considerable 
  

   number 
  were 
  there 
  secured. 
  It 
  may 
  be 
  stated, 
  as 
  bearing 
  on 
  the 
  question 
  of 
  

   the 
  season 
  during 
  which 
  G. 
  morsitans 
  breeds 
  most 
  freely, 
  that 
  the 
  large 
  haul 
  men- 
  

   tioned 
  above 
  was 
  secured 
  in 
  November 
  1914, 
  and 
  that 
  at 
  the 
  base 
  of 
  the 
  same 
  tree 
  

   in 
  August 
  1916 
  less 
  than 
  ten 
  live 
  pupae 
  were 
  secured, 
  although 
  fly 
  was 
  noted 
  as 
  being 
  

   ' 
  extremely 
  numerous 
  and 
  attentive." 
  This 
  observation 
  is 
  of 
  little 
  importance 
  

   in 
  itself, 
  but 
  is 
  mentioned 
  here 
  as 
  it 
  happens 
  to 
  be 
  in 
  accordance 
  with 
  the 
  conclusions 
  

   of 
  Lloyd 
  from 
  careful 
  notes 
  made 
  in 
  Northern 
  Rhodesia.f 
  It 
  is 
  to 
  be 
  remarked 
  also 
  

   that 
  in 
  the 
  writer's 
  previous 
  work 
  in 
  this 
  connection, 
  in 
  August 
  1911, 
  only 
  four 
  live 
  

   pupae 
  were 
  secured 
  amongst 
  a 
  total 
  of 
  ninety-one, 
  the 
  remaining 
  cases 
  being 
  empty. 
  

   Lamborn 
  also 
  supports 
  Lloyd's 
  observations 
  in 
  this 
  particular,^ 
  and 
  it 
  would 
  seem 
  that 
  

   the 
  diminution 
  in 
  the 
  breeding 
  rate 
  and 
  the 
  prolongation 
  of 
  the 
  pupal 
  period 
  during 
  

   the 
  colder 
  months 
  of 
  the 
  year 
  is 
  more 
  or 
  less 
  established. 
  Lloyd, 
  however, 
  came 
  to 
  

   a 
  further 
  conclusion, 
  namely 
  that 
  breeding 
  practically 
  ceases 
  during 
  the 
  wet 
  season§ 
  

   and 
  that 
  the 
  latter 
  part 
  of 
  the 
  dry 
  season, 
  from 
  July 
  to 
  October 
  or 
  November, 
  

   would 
  therefore 
  comprise 
  practically 
  the 
  whole 
  of 
  the 
  active 
  period 
  of 
  reproduction. 
  

   This 
  is 
  exactly 
  the 
  season 
  when 
  G. 
  morsitans 
  in 
  Southern 
  Rhodesia 
  is 
  concentrated 
  

   in 
  the 
  permanent 
  shade 
  bordering 
  on 
  vleis, 
  rivers, 
  etc., 
  and 
  it 
  would 
  certainly 
  be 
  

   of 
  considerable 
  interest 
  if 
  Lloyd's 
  deductions 
  in 
  this 
  respect 
  were 
  correct. 
  The 
  

   statement, 
  however, 
  needs 
  confirmation, 
  and 
  whilst 
  the 
  writer 
  is 
  unfamiliar 
  with 
  

   conditions 
  north 
  of 
  the 
  Zambesi, 
  it 
  would 
  appear 
  that 
  the 
  deduction 
  is 
  based 
  upon 
  

  

  * 
  Bull. 
  Ent. 
  Res., 
  ii., 
  p. 
  357. 
  

   f 
  Bull 
  Ent. 
  Ees. 
  v, 
  p. 
  58. 
  

   % 
  Bull. 
  Ent. 
  Res., 
  vii., 
  pp. 
  29-50. 
  

   § 
  Bull. 
  Ent. 
  Res., 
  v., 
  p. 
  58. 
  

  

  