﻿I 
  

  

  571 
  

  

  stage 
  averages 
  only 
  five 
  days, 
  so 
  that 
  there 
  are 
  several 
  generations 
  

   during 
  the 
  growth 
  of 
  the 
  crop. 
  The 
  lower 
  leaves 
  are 
  chiefly 
  attacked, 
  

   and 
  each 
  larva 
  may 
  be 
  responsible 
  for 
  several 
  blotches 
  on 
  one 
  leaf. 
  

   When 
  the 
  tobacco 
  is 
  flue-cured 
  the 
  caterpillars 
  are 
  killed, 
  but 
  when 
  

   air-cured, 
  quantities 
  are 
  to 
  be 
  found 
  hanging 
  to 
  it 
  by 
  silken 
  threads. 
  

   The 
  moths 
  hide 
  in 
  the 
  barns, 
  or 
  among 
  tobacco 
  stems 
  and 
  rubbish 
  

   on 
  the 
  field 
  left 
  after 
  harvest. 
  This 
  should 
  be 
  collected 
  and 
  burned, 
  

   and 
  when 
  the 
  plants 
  are 
  pulled 
  up 
  the 
  earth 
  clinging 
  to 
  the 
  roots 
  

   should 
  not 
  be 
  shaken 
  off, 
  but 
  thrown 
  on 
  to 
  the 
  fire 
  ; 
  many 
  pupae 
  will 
  

   thus 
  be 
  destroyed. 
  

  

  Papilio 
  demodociis 
  is 
  common 
  on 
  all 
  citrus 
  trees, 
  the 
  chief 
  damage 
  

   being 
  done 
  to 
  young 
  plants. 
  Handpicking 
  or, 
  in 
  the 
  nurseries, 
  spraying 
  

   "v\ith 
  arsenate 
  of 
  lead, 
  is 
  efficacious. 
  The 
  Citrus 
  Aphis 
  does 
  a 
  great 
  

   deal 
  of 
  damage 
  to 
  young 
  shoots 
  and 
  leaves, 
  retarding 
  growth 
  and 
  

   distorting 
  them. 
  Spraying 
  with 
  a 
  decoction 
  of 
  the 
  locally 
  grown 
  

   tobacco 
  is 
  an 
  effective 
  method 
  of 
  control. 
  The 
  Citrus 
  Psylla 
  {Trioza 
  

   sp.) 
  is 
  found 
  all 
  over 
  the 
  Protectorate 
  and, 
  though 
  not 
  a 
  serious 
  

   pest, 
  damages 
  young 
  shoots 
  and 
  leaves. 
  It 
  is 
  kept 
  in 
  check 
  by 
  

   natural 
  parasites, 
  and 
  the 
  larvae 
  may 
  be 
  killed 
  by 
  spraying 
  with 
  

   tobacco, 
  soap, 
  or 
  kerosene 
  emulsion. 
  Lepidosaphes 
  beckii, 
  Newm., 
  

   and 
  Icerya 
  purchasi 
  have 
  been 
  reported 
  on 
  citrus, 
  the 
  latter 
  also 
  

   on 
  wattle, 
  lemon, 
  orange, 
  roses 
  and 
  grass. 
  

  

  The 
  following 
  Aphids 
  are 
  recorded 
  : 
  — 
  Macrosiphum 
  lophospermum, 
  

   Theo., 
  sp. 
  n., 
  from 
  Lophospermu7n 
  erubescens 
  {Maurandia 
  barclayana) 
  ; 
  

   M. 
  lycopersicella, 
  Theo., 
  sp. 
  nov., 
  from 
  Cape 
  Tomato 
  ; 
  M. 
  antirrhinum^ 
  

   Macchiate, 
  from 
  Antirrhinum. 
  M. 
  granarium, 
  Kirby, 
  from 
  broom- 
  

   corn 
  (sorghum) 
  ; 
  Rhopalosiphum 
  lactucae, 
  Kalt., 
  from 
  Sonchus 
  ; 
  

   Aphis 
  gossypii, 
  Glover, 
  from 
  cotton 
  ; 
  A. 
  tavaresi, 
  Del 
  Guer., 
  from 
  

   orange 
  trees 
  ; 
  A. 
  solanella, 
  Theo., 
  sp. 
  nov., 
  from 
  Solanum 
  sp. 
  ; 
  A. 
  

   africana, 
  Theo., 
  sp. 
  nov., 
  from 
  broomcorn 
  (sorghum) 
  and 
  barley 
  ; 
  

   Toxoptera 
  graminum, 
  Rond., 
  from 
  wheat. 
  

  

  Rhumbler 
  (L.). 
  Die 
  Buchenrinden-Wollaus 
  {Gryptococcus 
  fagi) 
  und 
  

   ihre 
  Bekampfung. 
  [The 
  Felted 
  Beech 
  Coccus 
  and 
  its 
  control.]^ 
  

   J. 
  Neumann, 
  Neudamm, 
  n.d., 
  32 
  pp. 
  ; 
  price 
  20 
  Pfennige. 
  

  

  So 
  far, 
  records 
  have 
  been 
  made 
  of 
  over 
  500 
  trees 
  attacked 
  by 
  this 
  

   scale 
  in 
  the 
  Miinden 
  districts 
  of 
  Gahrenberg 
  and 
  Cattenbiihl. 
  It 
  

   usually 
  hibernates 
  as 
  a 
  wool-covered 
  larva, 
  firmly 
  fixed 
  to 
  the 
  bark. 
  

   From 
  April 
  to 
  June 
  the 
  larvae 
  transform 
  into 
  perfect 
  insects 
  

   and 
  oviposition 
  begins, 
  several 
  batches 
  of 
  eggs 
  being 
  laid 
  by 
  each 
  

   female 
  up 
  to 
  the 
  end 
  of 
  October. 
  During 
  August 
  and 
  September 
  

   hatching 
  requires 
  only 
  25 
  to 
  26 
  days 
  in 
  the 
  laboratory; 
  in 
  September 
  

   and 
  October 
  45 
  to 
  50 
  days 
  are 
  necessary 
  in 
  the 
  open 
  air. 
  The 
  

   strong-legged 
  young 
  larvae 
  are 
  able 
  to 
  travel 
  over 
  the 
  smooth 
  bark, 
  

   and 
  their 
  rate 
  of 
  progress 
  increases 
  at 
  higher 
  temperatures, 
  a 
  6-foot 
  

   climb 
  being 
  possible 
  on 
  a 
  warm 
  afternoon. 
  After 
  wandering 
  for 
  

   some 
  time 
  the 
  larva 
  fixes 
  itself 
  definitely. 
  Occasionally 
  wax 
  is 
  pro- 
  

   duced 
  before 
  this, 
  but 
  as 
  a 
  rule 
  the 
  secretion 
  only 
  begins 
  after 
  

   attachment. 
  The 
  ambulatory 
  larva 
  is 
  responsible 
  for 
  the 
  spread 
  of 
  

   infestation 
  on 
  a 
  given 
  tree, 
  but 
  the 
  dispersal 
  from 
  one 
  tree 
  to 
  another 
  

   is 
  due 
  to 
  the 
  wind-borne 
  waxy 
  secretion 
  containing 
  eggs. 
  The 
  

   dangerous 
  months 
  are 
  from 
  June 
  to 
  November 
  inclusive, 
  vSeptember 
  

  

  