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  present 
  on 
  sugar-cane 
  in 
  Queensland. 
  T. 
  ananas, 
  Tryon, 
  is 
  the 
  fore- 
  

   runner 
  of 
  a 
  disease 
  of 
  pine-apples 
  known 
  as 
  " 
  fruitlet 
  core 
  rot 
  " 
  in 
  

   Queensland. 
  T. 
  culmicolus, 
  Renter, 
  causes 
  a 
  disease 
  of 
  grasses 
  in 
  

   Finland. 
  T. 
  latus, 
  Bks., 
  was 
  found 
  injuring 
  mango 
  plants 
  in 
  Washing- 
  

   ton. 
  T. 
  approximatus, 
  Bks. 
  MS., 
  and 
  T. 
  assimilis, 
  Bks. 
  MS,, 
  have 
  been 
  

   taken 
  on 
  Citrus 
  in 
  California. 
  T. 
  buxi 
  is 
  stated 
  by 
  Green 
  to 
  have 
  

   destroyed 
  every 
  box-tree 
  in 
  the 
  Botanic 
  Gardens 
  at 
  Turin 
  in 
  one 
  season. 
  

   The 
  ribbed 
  tea 
  mite, 
  Phytoptus 
  carinatus, 
  Green, 
  is 
  recorded 
  in 
  Ceylon 
  

   from 
  Kegalle, 
  Ukuwela, 
  Nuwara 
  Eliya, 
  Haputale, 
  Peradeniya, 
  Gona- 
  

   kelle 
  and 
  Passara. 
  A 
  bush 
  badly 
  attacked 
  by 
  this 
  mite 
  has 
  every 
  leaf, 
  

   except 
  the 
  young 
  flush, 
  of 
  a 
  whitish 
  green 
  or 
  a 
  deep 
  bronze-colour, 
  

   resembling 
  those 
  of 
  copper 
  beech, 
  the 
  discoloration 
  being 
  more 
  marked 
  

   on 
  the 
  upper 
  surface. 
  The 
  mites 
  are 
  very 
  minute. 
  Watt 
  and 
  Mann 
  

   give 
  the 
  distribution 
  of 
  this 
  mite 
  as 
  Assam, 
  Darjeeling, 
  Duars 
  and 
  

   Ceylon. 
  

  

  Schneider- 
  Orelli 
  (0.). 
  Von 
  der 
  Blutlaus. 
  [The 
  Woolly 
  Aphis 
  

  

  (Schizoneura 
  lanigera, 
  Hausm.)]. 
  — 
  Schweiz 
  Zeits. 
  fur 
  Obst. 
  -und 
  

   Weinbau, 
  Frauenfeld, 
  xxii, 
  no. 
  23, 
  10th 
  Dec. 
  1913, 
  pp. 
  354-360, 
  

   6 
  figs. 
  

  

  In 
  1909, 
  Borner 
  stated 
  that 
  the 
  woolly 
  aphis 
  does 
  not 
  normally 
  lay 
  

   its 
  winter 
  eggs 
  on 
  apple-trees, 
  but 
  on 
  another 
  host-plant, 
  then 
  un- 
  

   known. 
  In 
  1912, 
  Dr. 
  Edith 
  Patch 
  obtained 
  direct 
  proof 
  that 
  this 
  

   insect 
  changes 
  its 
  host-plant, 
  and 
  she 
  was 
  led 
  to 
  conclude 
  that 
  the 
  

   woolly 
  Aphis 
  (Schizoneura 
  lanigera) 
  and 
  the 
  American 
  elm-leaf 
  aphis 
  

   [S. 
  americana) 
  are 
  not 
  specifically 
  distinct, 
  but 
  simply 
  different 
  stages 
  

   in 
  the 
  development 
  of 
  a 
  single 
  species 
  [cf. 
  this 
  Review 
  A, 
  i, 
  p. 
  24]. 
  

   According 
  to 
  this, 
  in 
  the 
  United 
  States 
  the 
  winged 
  forms 
  of 
  the 
  woolly 
  

   aphis 
  migrate 
  in 
  autumn 
  to 
  the 
  American 
  elm 
  (Ulmus 
  americana), 
  

   where 
  the 
  sexual 
  forms 
  and 
  the 
  winter-eggs 
  are 
  produced. 
  In 
  spring 
  

   the 
  newly 
  hatched 
  insects 
  and 
  their 
  young 
  suck 
  the 
  elm 
  leaves 
  and 
  

   cause 
  the 
  characteristic 
  gall 
  formation. 
  Early 
  in 
  the 
  summer 
  the 
  

   winged 
  forms 
  appear, 
  and 
  return 
  to 
  the 
  apple 
  and 
  similar 
  trees, 
  there 
  

   parthogenetically 
  producing 
  colonies 
  of 
  woolly 
  aphis. 
  In 
  Europe 
  

   the 
  American 
  elm 
  is 
  very 
  rarely 
  available 
  for 
  this 
  change, 
  but 
  European 
  

   species 
  (U. 
  campestris, 
  U. 
  effusa, 
  U. 
  montana) 
  abound, 
  and 
  on 
  all 
  of 
  

   them 
  — 
  especially 
  on 
  TJ. 
  camp)estris 
  — 
  galls 
  like 
  those 
  observed 
  by 
  Dr. 
  

   Patch 
  are 
  often 
  found. 
  But 
  these 
  galls 
  and 
  their 
  producer 
  {S. 
  ulmi) 
  

   have 
  been 
  known 
  since 
  the 
  middle 
  of 
  the 
  18th 
  century, 
  long 
  before 
  the 
  

   woolly 
  aphis 
  appeared. 
  Another 
  point 
  which 
  show^s 
  that 
  the 
  two 
  

   forms 
  are 
  distinct 
  is 
  that 
  Mordwilko 
  and 
  Tullgren 
  have 
  proved 
  that 
  

   S. 
  ulmi 
  regularly 
  migrates 
  to 
  the 
  roots 
  of 
  the 
  currant 
  and 
  gooseberry 
  

   and 
  there 
  produces 
  colonies 
  of 
  white 
  woolly 
  individuals 
  ; 
  further, 
  

   Dr. 
  Patch 
  has 
  recently 
  stated 
  that 
  the 
  antennae 
  of 
  the 
  woolly 
  aphis 
  

   (including 
  the 
  American 
  elm-aphis) 
  differ 
  considerably 
  from 
  those 
  of 
  

   the 
  European 
  elm-aphis. 
  This 
  statement 
  is 
  confirmed 
  by 
  the 
  author, 
  

   who 
  is 
  satisfied 
  that 
  the 
  European 
  elm-aphis 
  (S. 
  ulmi) 
  is 
  a 
  different 
  

   insect 
  from 
  the 
  woolly 
  aphis 
  of 
  the 
  apple. 
  It 
  remains 
  to 
  be 
  ascertained 
  

   whether 
  in 
  Europe 
  the 
  woolly 
  aphis 
  passes 
  the 
  whole 
  of 
  its 
  life-cycle 
  

   on 
  apple, 
  or 
  v^hether 
  it 
  does 
  actually 
  migrate 
  to 
  elms. 
  To 
  decide 
  

  

  