﻿376 
  W. 
  B. 
  JOHNSON 
  AND 
  LLEWELLYN 
  LLOYD. 
  

  

  narrowly 
  shaded 
  torrent 
  streams. 
  Like 
  palpalis, 
  tachinoides 
  is 
  absent 
  or 
  very 
  scarce 
  

   in 
  forests 
  so 
  dense 
  and 
  tangled 
  as 
  to 
  be 
  almost 
  impenetrable. 
  

  

  The 
  type 
  of 
  forest 
  is 
  certainly 
  the 
  main 
  controlling 
  factor 
  in 
  the 
  distribution 
  of 
  

   the 
  two 
  species 
  discussed, 
  but 
  this 
  is 
  not 
  the 
  case 
  with 
  morsitans. 
  In 
  the 
  height 
  of 
  

   the 
  dry 
  season, 
  when 
  the 
  grass 
  is 
  burnt, 
  this 
  species 
  seems 
  to 
  require 
  areas 
  of 
  good 
  

   shade 
  in 
  which 
  it 
  may 
  shelter 
  and 
  from 
  which 
  it 
  spreads 
  out 
  when 
  the 
  rains 
  begin. 
  

   Any 
  of 
  the 
  tachinoides 
  haunts 
  would 
  suit 
  it 
  in 
  this 
  respect, 
  but 
  in 
  the 
  Northern 
  

   Provinces 
  it 
  is 
  quite 
  localised, 
  and, 
  as 
  will 
  be 
  shown 
  later, 
  the 
  localisation 
  is 
  probably 
  

   connected 
  mainly 
  with 
  its 
  food 
  supply. 
  

  

  As 
  Simpson 
  (2) 
  pointed 
  out, 
  longipalpis 
  is 
  the 
  homologue 
  of 
  morsitans 
  in 
  the 
  wetter 
  

   parts 
  of 
  Nigeria 
  and 
  consequently 
  is 
  much 
  confined 
  to 
  the 
  southern 
  and 
  western 
  

   parts 
  of 
  the 
  Northern 
  Provinces. 
  On 
  the 
  Niger 
  from 
  Baro 
  to 
  Lokoja, 
  for 
  instance, 
  

   it 
  replaces 
  morsitans 
  in 
  much 
  the 
  same 
  way 
  that 
  palpalis 
  replaces 
  tachinoides 
  on 
  the 
  

   Benue. 
  At 
  Baro 
  in 
  October 
  morsitans 
  was 
  caught 
  in 
  excess 
  of 
  longipalpis 
  as 
  8 
  : 
  1, 
  

   while 
  at 
  Lokoja 
  these 
  proportions 
  were 
  reversed. 
  We 
  have 
  had 
  little 
  opportunity 
  

   of 
  observing 
  this 
  fly, 
  the 
  only 
  other 
  point 
  where 
  it 
  was 
  taken 
  being 
  between 
  Lafia 
  

   Beriberi 
  and 
  Benue 
  Bridge 
  in 
  Nassarawa. 
  

  

  2. 
  Classification 
  of 
  Forests 
  in 
  Relation 
  to 
  Tsetse-flies. 
  

  

  The 
  types 
  of 
  forest 
  given 
  below 
  grade 
  into 
  one 
  another 
  and 
  the 
  classification 
  is 
  

   a 
  crude 
  one, 
  but 
  it 
  will 
  indicate 
  sufficiently 
  to 
  medical 
  officers 
  and 
  others 
  the 
  species 
  

   of 
  tsetse 
  they 
  may 
  expect 
  to 
  find 
  in 
  various 
  places. 
  The 
  usual 
  Hausa 
  names 
  of 
  the 
  

   trees, 
  taken 
  from 
  Dr. 
  Dalziel's 
  very 
  useful 
  book, 
  " 
  A 
  Hausa 
  Botanical 
  Vocabulary," 
  

   are 
  given 
  in 
  parenthesis. 
  

  

  («) 
  Heavy 
  evergreen 
  shade 
  forest 
  with 
  such 
  trees 
  as 
  Eugenia 
  owariensis 
  (malmo), 
  

   Diospyros 
  mespiliformis 
  (kanya), 
  Vitex 
  cienkowskii 
  (dinya), 
  Adina 
  microcephala 
  

   (kadanyar 
  kurumi), 
  Ficus 
  platyphylla 
  (gamji), 
  Raphia 
  vinifera 
  (tukuruwa), 
  and 
  

   Phoenix 
  reclinata 
  (kajinjiri). 
  Example 
  in 
  Plate 
  xx, 
  fig. 
  1. 
  

  

  (1) 
  So 
  dense 
  as 
  to 
  be 
  almost 
  impenetrable 
  and 
  traversed 
  by 
  small 
  sluggish 
  

  

  streams 
  : 
  — 
  no 
  tsetse 
  or 
  very 
  scanty 
  palpalis. 
  

  

  (2) 
  Forming 
  a 
  narrow 
  border 
  to 
  a 
  torrent 
  stream 
  : 
  — 
  palpalis, 
  and, 
  very 
  rarely, 
  

  

  tachinoides. 
  

  

  (b) 
  Heavy 
  more 
  open 
  forest, 
  generally 
  filling 
  shallow 
  valleys 
  containing 
  per- 
  

   manent 
  water 
  in 
  the 
  north 
  and 
  east, 
  but 
  also 
  on 
  hillsides 
  in 
  the 
  south 
  and 
  west 
  ; 
  

   with 
  such 
  evergreen 
  trees 
  as 
  Chlorophora 
  excelsa 
  (loko), 
  Khaya 
  senegalensis 
  (madachi), 
  

   Eriodendron 
  orientate 
  (rimi), 
  Elaeis 
  guineensis 
  (kwakwa), 
  Borassus 
  flabellifera 
  (giginya), 
  

   and 
  Raphia 
  vinifera 
  ; 
  together 
  with 
  a 
  varying 
  admixture 
  of 
  the 
  following 
  deciduous 
  

   trees, 
  especially 
  on 
  the 
  outskirts 
  :—Isoberlinia 
  doka 
  (doka), 
  Pterocarpus 
  erinaceus 
  

   (madobia), 
  Pardaniellia 
  oliveri 
  (maje), 
  Parkia 
  filicoidea 
  (dorowa), 
  Prosopis 
  oblonga 
  

   (kiriya), 
  Butyrospermum 
  parkii 
  (kadanya), 
  Uapaca 
  guineensis 
  (ka 
  fafogo), 
  Odina 
  

   barteri 
  (faru). 
  

  

  Such 
  a 
  forest 
  on 
  Pati 
  Hill, 
  Lokoja, 
  is 
  shown 
  in 
  Plate 
  xx, 
  fig. 
  2. 
  

  

  (1) 
  Filling 
  shallow 
  vaUeys 
  containing 
  permanent 
  water 
  in 
  the 
  north 
  and 
  east 
  : 
  — 
  

  

  tachinoides, 
  morsitans, 
  and, 
  sporadically, 
  palpalis. 
  

  

  (2) 
  On 
  flat 
  ground 
  or 
  hillsides 
  in 
  the 
  south 
  and 
  west 
  : 
  — 
  palpalis, 
  tachinoides, 
  

  

  longipalpis, 
  and, 
  sometimes, 
  morsitans. 
  

  

  (c) 
  Less 
  evergreen 
  type 
  of 
  dense 
  forest 
  with 
  permanent 
  or 
  almost 
  permanent 
  

   water, 
  often 
  reduced 
  by 
  farming 
  to 
  half 
  a 
  dozen 
  trees 
  with 
  their 
  accompanying 
  

   undergrowth, 
  especially 
  common 
  in 
  the 
  north 
  and 
  east 
  ; 
  contains 
  such 
  trees 
  as 
  : 
  — 
  

   Khaya 
  senegalensis, 
  Ficus 
  gnaphalocarpa 
  (baure), 
  V. 
  cienkowskii, 
  Adina 
  microcephala, 
  

   Acacia 
  sieberiana 
  (farin 
  kaya) 
  and 
  other 
  acacias, 
  Anogeissus 
  leiocarpus 
  (marike), 
  

   Erythrina 
  senegalensis 
  (minjiriya), 
  Mimosa 
  asperata 
  (kaidaji), 
  with 
  thickets 
  of 
  the 
  

   trailing 
  thorny 
  leguminous 
  Dichrostachys 
  platycarpa 
  (sarkakiya). 
  This 
  type 
  is 
  shown 
  

  

  