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  159 
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  far 
  noticed 
  on 
  the 
  beet 
  root 
  are 
  few 
  in 
  number, 
  and 
  have 
  rarely 
  been 
  of 
  

   great 
  importance. 
  Our 
  present 
  list 
  of 
  those 
  infesting 
  the 
  root 
  of 
  the 
  

   Taeet 
  is 
  limited 
  to 
  two 
  species 
  of 
  plant-lice 
  {^Pemphigus 
  beta, 
  and 
  Aphis 
  

   middletonii) 
  and 
  a 
  single 
  mealy 
  bug 
  {D'aciyhpins), 
  the 
  species 
  of 
  which 
  

   is 
  uncertain. 
  

  

  ROOT-LICE 
  {Aphidida 
  and 
  Coccidce). 
  

  

  The 
  Beet 
  Aphis. 
  

  

  Pemphigus 
  betce 
  Doane. 
  

  

  This 
  insect, 
  but 
  very 
  lately 
  brought 
  to 
  the 
  attention 
  of 
  beet-growers, 
  

   offers 
  an 
  extraordinary 
  example 
  of 
  the 
  injury 
  to 
  vegetation 
  which 
  may 
  

   be 
  done 
  by 
  root-lice. 
  Our 
  information 
  concerning 
  it 
  is 
  due 
  to 
  Mr. 
  R. 
  

   W. 
  Doane, 
  Assistant 
  Zoologist 
  of 
  the 
  Washington 
  State 
  Agricultural 
  

   Experiment 
  Station, 
  at 
  Pullman, 
  Wash., 
  whose 
  latest 
  publication 
  on 
  this 
  

   species 
  is 
  contained 
  in 
  Bulletin 
  42 
  of 
  that 
  Station. 
  

  

  Attention 
  was 
  first 
  called 
  to 
  this 
  pest, 
  he 
  says, 
  in 
  1896, 
  when 
  it 
  was 
  

   found 
  that 
  a 
  field 
  of 
  two 
  or 
  three 
  acres 
  of 
  beets 
  was 
  generally 
  infested, 
  

  

  a 
  strip 
  of 
  twenty-five 
  to 
  a 
  hun- 
  

   dred 
  yards 
  being 
  so 
  badly 
  in- 
  

   jured 
  that 
  the 
  beets 
  were 
  nearly 
  

   all 
  soft 
  and 
  spongy, 
  and 
  the 
  

   plants 
  much 
  smaller 
  than 
  the 
  

   average. 
  Other 
  beet 
  fields 
  in 
  

   the 
  vicinity 
  of 
  this 
  were 
  also 
  

   generally 
  infested. 
  During 
  sub- 
  

   sequent 
  years 
  this 
  aphis 
  has 
  

   been 
  found 
  in 
  considerable 
  

   numbers 
  in 
  almost 
  every 
  beet 
  

   field 
  in 
  that 
  locality, 
  and 
  in 
  

   1899 
  it 
  was 
  unusually 
  destruc- 
  

   tive. 
  

  

  It 
  was 
  first 
  described 
  as 
  a 
  new 
  species 
  by 
  Mr. 
  Doane 
  in 
  1900, 
  and 
  

   seems 
  thus 
  far 
  to 
  have 
  been 
  found 
  only 
  in 
  Washington 
  and 
  Oregon. 
  In 
  

   the 
  latter 
  state 
  it 
  has 
  been 
  even 
  more 
  destructive 
  than 
  in 
  Washington, 
  

   at 
  least 
  a 
  thousand 
  tons 
  of 
  beets 
  having 
  been 
  destroyed 
  by 
  it 
  in 
  one 
  

   year 
  in 
  a 
  single 
  valley 
  devoted 
  largely 
  to 
  beet 
  culture. 
  Like 
  very 
  many 
  

   other 
  beet 
  insects, 
  this 
  species 
  infests 
  also 
  several 
  wild 
  or 
  useless 
  plants; 
  

   a 
  wild 
  yarrow 
  {Achilla'a 
  laniilosa 
  Nutt.) 
  and 
  a 
  knot-weed 
  {Polygonum 
  

   aviculare), 
  together 
  with 
  various 
  other 
  weeds 
  and 
  grasses, 
  both 
  native 
  

   and 
  introduced. 
  It 
  has 
  also 
  been 
  reported 
  as 
  occurring 
  on 
  potatoes, 
  

   cultivated 
  roses, 
  and 
  the 
  wild 
  service-berry, 
  but 
  its 
  identity 
  in 
  these 
  

   <;ases 
  is 
  as 
  yet 
  in 
  doubt. 
  

  

  This 
  root 
  aphis 
  occurs 
  in 
  two 
  forms, 
  wingless 
  and 
  winged, 
  the 
  

  

  Fig. 
  S7. 
  'X\i^^e.e.X 
  \'^\i\%. 
  Pemphigus 
  bctie 
  : 
  «, 
  winged 
  

   female; 
  b, 
  wingless 
  female; 
  r, 
  antenna 
  of 
  winged 
  female. 
  

   (Doane.) 
  

  

  