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  practice 
  of 
  planters 
  to 
  top 
  the 
  plants 
  as 
  soon 
  as 
  the 
  flowers 
  appear, 
  

   and 
  where 
  this 
  is 
  done 
  consistently, 
  there 
  is 
  little 
  evidence 
  of 
  this 
  

   pest 
  ; 
  to 
  obtain 
  seed, 
  the 
  flower 
  stalks 
  are 
  usually 
  enclosed 
  in 
  a 
  bag. 
  

   As 
  neglected 
  fields 
  always 
  show 
  signs 
  of 
  the 
  borer, 
  the 
  plants 
  in 
  

   abandoned 
  fields 
  should 
  be 
  ploughed 
  up 
  and 
  destroyed 
  to 
  avoid 
  a 
  

   general 
  infestation. 
  Frontina 
  archippivora 
  has 
  been 
  bred 
  from 
  the 
  

   pupa 
  of 
  C. 
  obsoleta, 
  the 
  eggs 
  of 
  which 
  are 
  probably 
  parasitised 
  by 
  

   Trichogramma 
  pretiosum. 
  

  

  The 
  tobacco 
  hornworm, 
  Protoparce 
  {Phlegethontiusquin) 
  quemaculatus, 
  

   is 
  sometimes 
  found 
  on 
  the 
  wild 
  tobacco 
  (Nicotiana 
  glauca), 
  but 
  its 
  

   rare 
  occurrence 
  would 
  indicate 
  the 
  presence 
  of 
  efficient 
  parasites. 
  

   Infested 
  plants 
  should 
  be 
  sprayed 
  with 
  lead 
  arsenate 
  — 
  3 
  pounds 
  to 
  

   100 
  U.S. 
  gallons 
  (83 
  Imp. 
  gallons) 
  of 
  water. 
  

  

  Both 
  the 
  larva 
  and 
  adult 
  of 
  the 
  tobacco 
  flea-beetle 
  (Epitrix 
  parvula) 
  

   are 
  injurious, 
  and 
  also 
  feed 
  on 
  potatoes, 
  tomatoes, 
  egg-plant, 
  etc. 
  

   In 
  some 
  places 
  this 
  beetle 
  becomes 
  numerous 
  and 
  injurious 
  only 
  

   in 
  the 
  dry 
  season, 
  but 
  in 
  neglected 
  plantations, 
  and 
  especially 
  in 
  the 
  

   neighbourhood 
  of 
  other 
  solanaceous 
  plants, 
  it 
  is 
  very 
  prevalent. 
  In 
  

   Hawaii 
  the 
  fife- 
  cycle 
  would 
  probably 
  be 
  somewhat 
  shorter 
  than 
  in 
  

   the 
  United 
  States. 
  When 
  this 
  beetle 
  is 
  present 
  in 
  sufficient 
  numbers 
  

   to 
  damage 
  the 
  crop, 
  the 
  affected 
  plants 
  may 
  be 
  sprayed 
  with 
  arsenate 
  

   of 
  lead, 
  in 
  paste 
  form, 
  1 
  pound 
  to 
  20 
  U.S. 
  gallons 
  (IGJ 
  Imp.) 
  of 
  water, 
  

   (only 
  one-haK 
  of 
  this 
  amount 
  of 
  powdered 
  arsenate 
  of 
  lead), 
  which 
  

   will 
  kill 
  any 
  beetles 
  feeding 
  on 
  the 
  sprayed 
  fohage. 
  

  

  Minor 
  pests 
  of 
  tobacco 
  include 
  the 
  larvae 
  of 
  Plusia 
  chalcytes 
  and 
  

   Amorhia 
  emigratella 
  (Sparganothidae) 
  ; 
  the 
  Coccids, 
  Pseudococcus 
  citri, 
  

   P. 
  virgatus, 
  and 
  Pulvinaria 
  psidii 
  ; 
  the 
  Orthoptera, 
  Elimaea 
  appendi- 
  

   culata 
  and 
  Xiphidium 
  varipenne 
  ; 
  the 
  Lygaeid 
  bug, 
  Nysius 
  delectus 
  ; 
  

   and 
  a 
  bark 
  beetle, 
  Xyleborus 
  sp. 
  

  

  The 
  only 
  pest 
  of 
  stored 
  tobacco 
  mentioned 
  is 
  the 
  cigarette 
  beetle 
  

   (Lasioderma 
  serricarne), 
  against 
  which 
  fumigation 
  and 
  cold 
  storage 
  

   [see 
  this 
  Review, 
  Ser. 
  A, 
  i, 
  p. 
  171] 
  are 
  recommended 
  ; 
  the 
  natural 
  

   enemies 
  include 
  a 
  species 
  of 
  Pteromalus. 
  

  

  VuiLLET 
  (J. 
  & 
  A.). 
  Les 
  Pucerons 
  du 
  Sorgho 
  au 
  Soudan 
  Francais. 
  [The 
  

   Millet 
  Aphis 
  in 
  the 
  French 
  Sudan.] 
  — 
  VAgron. 
  Colon., 
  Paris, 
  i, 
  

   no8. 
  11-12, 
  ii, 
  no. 
  13, 
  31st 
  May-30th 
  June-3 
  1st 
  July 
  1914 
  ; 
  pp. 
  

   137-143, 
  161-165, 
  17-23 
  ; 
  8 
  figs. 
  

  

  Failures 
  of 
  the 
  Sudanese 
  millet 
  crop 
  are 
  chiefly 
  due 
  to 
  drought 
  or 
  

   to 
  the 
  attacks 
  of 
  aphids, 
  Aphis 
  sorghi, 
  Theo., 
  and 
  A. 
  maidis. 
  Fitch, 
  

   being 
  responsible 
  for 
  the 
  injury 
  in 
  the 
  latter 
  case. 
  A. 
  sorghella, 
  

   Schouteden, 
  is 
  considered 
  to 
  be 
  a 
  synonym 
  of 
  A. 
  sorghi, 
  which 
  has 
  

   been 
  found 
  only 
  on 
  sorghum 
  {Andropogon 
  sorghum, 
  Brot.). 
  In 
  the 
  

   Koutiala-Bani 
  district, 
  A. 
  sorghi 
  was 
  noticed 
  on 
  old 
  stools 
  on 
  the 
  

   14th 
  June, 
  a 
  time 
  at 
  which 
  the 
  year's 
  sorghum 
  sowings 
  were 
  already 
  

   sufficiently 
  advanced 
  to 
  shelter 
  the 
  insect. 
  Thus 
  the 
  one 
  host-plant 
  

   alone 
  suffices 
  to 
  support 
  the 
  existence 
  of 
  this 
  species. 
  In 
  the 
  French 
  

   Sudan, 
  parthenogenetic 
  viviparous 
  females, 
  winged 
  or 
  apterous, 
  

   reproduce 
  continuously. 
  Laboratory 
  experiments 
  show 
  that 
  apterous 
  

   individuals 
  five 
  from 
  24 
  to 
  28 
  days. 
  Five 
  days 
  after 
  birth 
  they 
  begin 
  

   to 
  produce 
  larvae 
  at 
  the 
  rate 
  of 
  from 
  5 
  to 
  10 
  every 
  24 
  hours 
  during 
  

   from 
  8 
  to 
  10 
  days. 
  Fertility 
  then 
  decreases 
  rapidly 
  and 
  ceases 
  about 
  

  

  