﻿202 
  W. 
  A. 
  LAMBORN. 
  — 
  THE 
  AGRICULTURAL 
  PESTS 
  

  

  The 
  latter 
  was 
  found 
  to 
  be 
  a 
  late 
  season 
  pest, 
  breeding 
  in 
  opened 
  bolls 
  and 
  attacking 
  

   the 
  seeds. 
  It 
  was 
  frequently 
  found 
  in 
  lint 
  removed 
  from 
  the 
  bolls 
  put 
  aside 
  for 
  the 
  

   purpose 
  of 
  ginning. 
  The 
  enormous 
  numbers 
  of 
  D. 
  superstitiosus 
  (49,000 
  were 
  collected 
  

   in 
  November 
  from 
  46 
  acres) 
  were 
  to 
  be 
  accounted 
  for, 
  in 
  my 
  opinion, 
  by 
  their 
  swarming 
  

   in 
  from 
  the 
  farms 
  and 
  bush 
  adjoining 
  the 
  plantation, 
  attracted 
  to 
  their 
  favourite 
  

   food-plants. 
  

  

  A 
  fact 
  of 
  much 
  interest 
  is 
  that 
  B. 
  superstitiosus 
  and 
  D. 
  melanoderes 
  occasionally 
  

   interbreed, 
  for 
  a 
  male 
  of 
  the 
  former 
  species 
  was 
  taken 
  in 
  coitu 
  with 
  a 
  female 
  of 
  the 
  

   latter 
  from 
  which 
  eleven 
  offspring, 
  all 
  superstitiosus, 
  were 
  reared 
  in 
  the 
  laboratory, 
  

   a 
  result 
  in 
  accordance 
  with 
  Mendelian 
  expectation. 
  The 
  life-cycle 
  in 
  the 
  laboratory, 
  

   from 
  egg 
  to 
  imago, 
  occupied 
  29 
  days 
  only, 
  though 
  a 
  previous 
  observer 
  has 
  recorded 
  

   68 
  to 
  72 
  days 
  as 
  its 
  duration, 
  and 
  it 
  seems 
  to 
  me 
  quite 
  probable 
  that 
  under 
  natural 
  

   conditions 
  with 
  an 
  abundance 
  of 
  fresh 
  food 
  the 
  period 
  would 
  be 
  even 
  shorter. 
  My 
  

   own 
  observations 
  confirm 
  a 
  previous 
  statement 
  that 
  superstitiosus 
  oviposits 
  in 
  the 
  

   ground 
  and 
  not, 
  as 
  would 
  be 
  expected, 
  on 
  the 
  food-plant, 
  and 
  the 
  newly 
  hatched 
  

   larvae 
  feed 
  on 
  any 
  cotton 
  debris 
  they 
  can 
  find, 
  and 
  then, 
  crawling 
  up 
  the 
  stems, 
  find 
  

   their 
  way 
  to 
  the 
  bolls. 
  

  

  Small 
  nets 
  were 
  successfully 
  employed 
  for 
  collecting 
  immature 
  wingless 
  stainers, 
  

   which, 
  congregating 
  on 
  bolls 
  and 
  at 
  the 
  extremities 
  of 
  the 
  branches, 
  were 
  readily 
  

   shaken 
  off. 
  Many 
  were 
  shaken 
  by 
  small 
  boys 
  into 
  wide-mouthed 
  tins 
  containing 
  

   water 
  and 
  a 
  small 
  amount 
  of 
  kerosene, 
  a 
  method 
  suitable 
  for 
  the 
  native 
  farmer. 
  

   The 
  large 
  stainer 
  net, 
  as 
  used 
  in 
  the 
  West 
  Indies, 
  was 
  thoroughly 
  tested, 
  but 
  was 
  not 
  

   found 
  to 
  have 
  any 
  real 
  practical 
  value 
  against 
  the 
  Nigeria 
  insects, 
  for 
  the 
  adult 
  stainers 
  

   only 
  fell 
  off 
  when 
  the 
  plant 
  was 
  shaken 
  excessively, 
  to 
  such 
  an 
  extent 
  as 
  to 
  render 
  

   damage 
  probable, 
  and 
  more 
  often 
  than 
  not 
  they 
  took 
  to 
  flight 
  instead 
  of 
  falling. 
  

   Moreover, 
  the 
  methods 
  of 
  cultivation 
  and 
  the 
  habit 
  in 
  growth 
  of 
  the 
  cotton 
  plants 
  

   under 
  trial 
  did 
  not 
  permit 
  the 
  ready 
  use 
  of 
  such 
  an 
  appliance. 
  

  

  Hand-picking 
  seems 
  likely 
  to 
  prove 
  the 
  most 
  efficacious 
  method 
  of 
  controlling 
  the 
  

   pest. 
  By 
  hand-picking 
  49,453 
  stainers, 
  the 
  great 
  majority 
  of 
  which 
  were 
  mature 
  

   breeding 
  insects, 
  with 
  7,081 
  larvae 
  and 
  2,120 
  pupae 
  of 
  the 
  leaf-roller, 
  Sylepta 
  derogata, 
  

   were 
  collected 
  in 
  the 
  month 
  of 
  November 
  from 
  the 
  46 
  acres 
  under 
  cotton, 
  at 
  a 
  cost 
  of 
  

   £4, 
  so 
  that 
  if 
  the 
  labour 
  of 
  small 
  boys 
  is 
  utilised, 
  the 
  method 
  can 
  hardly 
  be 
  considered 
  

   an 
  expensive 
  one. 
  Probably 
  if 
  a 
  larger 
  gang 
  than 
  ten 
  had 
  been 
  put 
  on 
  to 
  the 
  work 
  

   earlier 
  in 
  the 
  season, 
  the 
  results 
  would 
  have 
  been 
  even 
  more 
  effective. 
  Hand-picking 
  

   has 
  the 
  advantage 
  also 
  in 
  that 
  other 
  pests, 
  e.g., 
  the 
  leaf 
  -roller, 
  can 
  be 
  dealt 
  with 
  at 
  the 
  

   same 
  time 
  ; 
  but 
  for 
  the 
  method 
  to 
  be 
  really 
  effective, 
  it 
  would 
  be 
  essential 
  that 
  there 
  

   should 
  be 
  co-operation, 
  year 
  after 
  year, 
  among 
  all 
  the 
  farmers 
  in 
  the 
  cotton 
  districts. 
  

   Evidence 
  of 
  the 
  value 
  of 
  the 
  measure 
  was 
  afforded 
  by 
  the 
  excellence 
  of 
  the 
  cotton 
  

   grown, 
  which, 
  in 
  spite 
  of 
  attack 
  by 
  these 
  pests 
  in 
  hordes, 
  was 
  yet 
  awarded 
  by 
  the 
  

   British 
  Cotton 
  Growing 
  Association 
  the 
  prize 
  annually 
  offered 
  for 
  the 
  best 
  cotton 
  

   grown 
  in 
  countries 
  in 
  which 
  they 
  have 
  interests. 
  

  

  Some 
  General 
  Remarks 
  on 
  Cotton. 
  

  

  Mixed 
  cultivation, 
  as 
  was 
  pointed 
  out 
  by 
  Jemmett 
  in 
  1910, 
  certainly 
  has 
  the^ 
  

   advantage 
  of 
  decreasing 
  the 
  spread 
  of 
  insect 
  pests. 
  Other 
  Malvaceae 
  should 
  obviously 
  

   not 
  be 
  planted 
  in 
  the 
  vicinity 
  of 
  cotton, 
  unless 
  it 
  is 
  intended 
  to 
  collect 
  pests 
  on 
  thenv 
  

  

  