﻿380 
  

  

  W. 
  B. 
  JOHNSON 
  AND 
  LLEWELLYN 
  LLOYD. 
  

  

  from 
  wet 
  by 
  a 
  ditch 
  and 
  a 
  thatched 
  roof 
  4 
  ft 
  above) 
  constructed 
  at 
  the 
  beginning 
  

   of 
  May 
  yielded 
  : 
  — 
  3rd-9th 
  May, 
  3 
  tachinoides 
  pupae 
  ; 
  10th-15th 
  May, 
  6 
  tachinoides 
  

   pupae 
  ; 
  16th-23rd 
  May, 
  1 
  palpalis 
  pupa 
  ; 
  all 
  producing 
  healthy 
  flies. 
  Up 
  to 
  the 
  

   middle 
  of 
  July 
  no 
  more 
  pupae 
  were 
  deposited 
  there. 
  

  

  Apart 
  from 
  the 
  above 
  indirect 
  and, 
  it 
  is 
  admitted, 
  slight 
  evidence 
  of 
  the 
  check 
  

   in 
  breeding, 
  there 
  is 
  the 
  more 
  conclusive 
  evidence 
  obtained 
  by 
  the 
  examination 
  of 
  

   the 
  female 
  flies. 
  The 
  figures 
  which 
  are 
  shown 
  in 
  Table 
  I 
  and 
  Diagram 
  I 
  were 
  

   obtained 
  from 
  October 
  to 
  April 
  by 
  dissection, 
  in 
  May 
  partly 
  by 
  dissection 
  and 
  partly 
  

   by 
  external 
  examination, 
  from 
  June 
  onwards 
  by 
  external 
  examination 
  only. 
  The 
  

   meteorological 
  data 
  were 
  collected 
  from 
  the 
  nearest 
  recording 
  stations 
  to 
  the 
  areas 
  

   where 
  the 
  flies 
  were 
  examined. 
  In 
  October, 
  the 
  last 
  month 
  of 
  the 
  rains, 
  dry 
  warm 
  

   spells 
  with 
  intervening 
  tornados, 
  16 
  per 
  cent, 
  of 
  the 
  females 
  were 
  pregnant. 
  In 
  the 
  

   first 
  three 
  months 
  of 
  the 
  dry 
  season 
  and 
  in 
  a 
  much 
  drier 
  part 
  of 
  the 
  country 
  the 
  

   pregnant 
  females 
  totalled 
  79, 
  70 
  and 
  78 
  per 
  cent, 
  respectively, 
  the 
  last 
  figure 
  being 
  

   obtained 
  from 
  a 
  very 
  small 
  number 
  of 
  flies. 
  In 
  February 
  there 
  is 
  a 
  fall 
  to 
  64 
  per 
  cent., 
  

   and 
  in 
  March 
  a 
  further 
  fall 
  to 
  59 
  per 
  cent., 
  due 
  in 
  all 
  probability 
  to 
  the 
  increasing 
  preva- 
  

   lence 
  of 
  recently 
  emerged 
  flies. 
  In 
  the 
  first 
  tornado 
  month, 
  April, 
  the 
  figure 
  rises 
  

   again 
  to 
  79 
  per 
  cent., 
  but 
  this 
  coincided 
  with 
  a 
  change 
  to 
  a 
  locality 
  where 
  tachinoides 
  

   was 
  particularly 
  thriving. 
  From 
  that 
  month 
  onwards 
  in 
  this 
  same 
  area 
  there 
  was 
  

   a 
  very 
  considerable 
  fall 
  in 
  the 
  proportion 
  of 
  pregnant 
  flies. 
  As 
  will 
  be 
  shown 
  later, 
  

   the 
  variation 
  in 
  pregnancy 
  may 
  be 
  correlated 
  with 
  a 
  variation 
  in 
  the 
  amount 
  of 
  

   food 
  taken. 
  That 
  most 
  of 
  the 
  breeding 
  takes 
  place 
  during 
  the 
  greatest 
  concentration 
  

   of 
  the 
  fly 
  is 
  a 
  point 
  of 
  practical 
  importance. 
  

  

  TABLE 
  1. 
  

  

  Showing 
  the 
  Seasonal 
  Variation 
  in 
  Larva 
  Production 
  of 
  G.' 
  tachinoides, 
  and 
  its 
  Correlation 
  with 
  

  

  Nutrition. 
  

  

  Month. 
  

  

  Food 
  content 
  of 
  gut 
  

  

  u 
  T3 
  

  

  0J 
  yi 
  <U 
  

  

  log 
  

  

  <D 
  

  

  <u 
  5 
  o 
  ^3 
  

   ^ 
  2 
  

  

  Pregnancy. 
  

  

  u 
  <d 
  a 
  

  

  re 
  c 
  

   c 
  a 
  

  

  8 
  0° 
  

  

  ft, 
  o- 
  

  

  Meteorological 
  Data. 
  

  

  oi 
  a 
  

  

  Temperature. 
  

  

  2 
  S 
  

  

  5« 
  

  

  oS 
  

   .2 
  3 
  

  

  <3 
  

  

  October, 
  1921 
  

   November, 
  1921 
  

   December, 
  1921 
  

   January, 
  1922 
  

   February, 
  1922 
  

   March, 
  1922 
  

   April, 
  1922 
  

   May, 
  1922 
  

   June, 
  1922 
  

   July, 
  1922 
  

   August, 
  1922 
  

   September, 
  1922 
  

  

  

  93 
  

  

  30- 
  

  

  

  199 
  

  

  68- 
  

  

  

  180 
  

  

  75- 
  

  

  

  36 
  

  

  53- 
  

  

  

  394 
  

  

  57- 
  

  

  

  180 
  

  

  54- 
  

  

  

  100 
  

  

  76- 
  

  

  

  316 
  

  

  45- 
  

  

  

  100 
  

  

  34- 
  

  

  

  100 
  

  

  34- 
  

  

  

  100 
  

  

  34- 
  

  

  

  100 
  

  

  14- 
  

  

  •0 
  

   •0 
  

   •0 
  

   •0 
  

   •0 
  

   •0 
  

   •0 
  

   •0 
  

   •0 
  

   ■0 
  

   •0 
  

   •0 
  

  

  51 
  

  

  16-0 
  

  

  107 
  

  

  79-0 
  

  

  73 
  

  

  70-0 
  

  

  9 
  

  

  78-0 
  

  

  203 
  

  

  64-0 
  

  

  54 
  

  

  59-0 
  

  

  52 
  

  

  79-0 
  

  

  2,032 
  

  

  33-0 
  

  

  2,830 
  

  

  39-0 
  

  

  2,722 
  

  

  21-0 
  

  

  2,417 
  

  

  20-0 
  

  

  3,361 
  

  

  22-0 
  

  

  Lokoja 
  

  

  Zaria 
  

  

  Bauchi 
  

  

  Keffi 
  

  

  Ibi 
  

  

  Bauchi 
  

  

  Zaria 
  

  

  Mashiwashi 
  

  

  3-6 
  

  

  80-8 
  

  

  89-7 
  

  

  nil- 
  

  

  70-6 
  

  

  . 
  90-0 
  

  

  nil 
  

  

  77-0 
  

  

  97-0 
  

  

  0-14 
  

  

  79-5 
  

  

  100-0 
  

  

  0-79 
  

  

  83-4 
  

  

  104-0 
  

  

  nil 
  

  

  84-4 
  

  

  107-0 
  

  

  1-86 
  

  

  76-7 
  

  

  96-0 
  

  

  3-21 
  

  

  80-8 
  

  

  100-0 
  

  

  6-12 
  

  

  76-1 
  

  

  87-0 
  

  

  5-5 
  

  

  74-8 
  

  

  84-0 
  

  

  14-0 
  

  

  73-8 
  

  

  83-0 
  

  

  14-6 
  

  

  75-9 
  

  

  85-0 
  

  

  71-8 
  

   46-0 
  

   50-0 
  

   54-0 
  

   57-0 
  

   63-0 
  

   55-0 
  

   68-0 
  

   67-0 
  

   67-0 
  

   67-0 
  

   67-0 
  

  

  3. 
  Glossina 
  morsitans. 
  

  

  We 
  have 
  paid 
  no 
  special 
  attention 
  to 
  the 
  breeding 
  haunts 
  of 
  this 
  fly, 
  as 
  we 
  have 
  

   spent 
  only 
  short 
  periods 
  in 
  places 
  where 
  it 
  was 
  numerous. 
  Its 
  pupae 
  were 
  found 
  

   in 
  association 
  with 
  those 
  of 
  tachinoides 
  at 
  Dau 
  (Gombe 
  Division) 
  in 
  sand 
  below 
  

   bushes, 
  and 
  again 
  in 
  the 
  stream-bed 
  at 
  Mashiwashi 
  to 
  the 
  number 
  of 
  82. 
  

  

  