﻿ORCHARD 
  INSECTS 
  PACIFIC 
  NORTHWEST 
  

  

  11 
  

  

  age 
  nearest 
  the 
  ground 
  and 
  grad- 
  

   ually 
  extending 
  their 
  operations 
  

   to 
  cover 
  the 
  whole 
  tree. 
  The 
  mites 
  

   are 
  usually 
  greenish 
  or 
  yellowish 
  

   while 
  feeding, 
  often 
  with 
  two 
  

   dark 
  spots 
  on 
  the 
  body. 
  The 
  eggs, 
  

   which 
  are 
  almost 
  colorless, 
  are 
  

   laid 
  in 
  the 
  webbing 
  (fig. 
  11, 
  A). 
  

   The 
  young 
  look 
  like 
  the 
  adults, 
  

   but 
  have 
  only 
  six 
  legs 
  instead 
  of 
  

   eight. 
  The 
  mites 
  develop 
  from 
  

   egg 
  to 
  adult 
  in 
  a 
  week 
  or 
  10 
  days, 
  

   and 
  there 
  are 
  several 
  generations 
  

   in 
  a 
  year. 
  They 
  can 
  therefore 
  be- 
  

   come 
  exceedingly 
  numerous 
  in 
  

   one 
  season. 
  Late 
  in 
  July 
  or 
  in 
  

   August, 
  particularly 
  if 
  the 
  infes- 
  

   tation 
  is 
  severe 
  and 
  the 
  mites 
  are 
  

   crowded, 
  many 
  of 
  the 
  adults 
  cease 
  

   feeding, 
  become 
  reddish 
  or 
  orange, 
  

   and 
  migrate 
  to 
  their 
  hibernating 
  

   places. 
  Since 
  this 
  migration 
  is 
  

   downward, 
  many 
  of 
  them 
  collect 
  

   around 
  the 
  calyx 
  ends 
  of 
  apples, 
  

   where 
  they 
  spin 
  webbing 
  that 
  

   takes 
  on 
  the 
  appearance 
  of 
  cello- 
  

   phane. 
  This 
  species 
  thrives 
  on 
  

   many 
  kinds 
  of 
  fruit 
  trees 
  and 
  also 
  

   on 
  a 
  milkweed 
  {Apocyiium) 
  that 
  

   grows 
  in 
  the 
  orchards, 
  but 
  it 
  is 
  es- 
  

   pecially 
  injurious 
  to 
  apple. 
  

  

  The 
  Willamette 
  mite 
  is 
  particu- 
  

   larly 
  injurious 
  to 
  apple 
  and 
  pear 
  

   trees 
  in 
  the 
  Hood 
  Eiver 
  and 
  Rogue 
  

   River 
  Valleys 
  of 
  Oregon. 
  It 
  

   looks 
  something 
  like 
  the 
  Pacific 
  

   mite 
  but 
  spins 
  less 
  webbing. 
  

  

  The 
  European 
  red 
  mite 
  lays 
  

   bright 
  red 
  overwintering 
  eggs 
  on 
  

   the 
  twigs 
  and 
  branches 
  of 
  fruit 
  

   trees 
  (fig. 
  12), 
  and 
  when 
  these 
  

   eggs 
  are 
  numerous 
  they 
  are 
  notice- 
  

   able 
  as 
  reddish 
  patches 
  on 
  the 
  

   bark. 
  They 
  are 
  also 
  found 
  in 
  the 
  

   catyx 
  end 
  of 
  mature 
  apples 
  (fig. 
  

   13). 
  These 
  eggs 
  hatch 
  in 
  April 
  

   just 
  before 
  the 
  blossoms 
  open. 
  

   The 
  mites 
  feed 
  on 
  the 
  foliage, 
  

   usually 
  on 
  the 
  underside, 
  and 
  spin 
  

   little 
  webbing. 
  They 
  are 
  more 
  

   easily 
  seen 
  than 
  the 
  Pacific 
  mite, 
  

   being 
  velvety 
  or 
  brownish 
  red, 
  

   with 
  conspicuous 
  whitish, 
  curved 
  

  

  spines 
  on 
  the 
  back. 
  During 
  the 
  

   summer 
  the 
  eggs 
  are 
  laid 
  on 
  the 
  

   leaves, 
  and 
  there 
  are 
  seven 
  or 
  eiofht 
  

  

  Figure 
  12. 
  — 
  Overwintering 
  eggs 
  of 
  the 
  

   European 
  red 
  mite. 
  

  

  generations 
  in 
  a 
  season. 
  This 
  

   species 
  is 
  seldom 
  found 
  except 
  on 
  

   deciduous 
  fruit 
  trees. 
  

  

  

  

  i%v«%|;*'-^ 
  

  

  Figure 
  13. 
  — 
  Winter 
  eggs 
  of 
  the 
  European 
  

   red 
  mite 
  in 
  the 
  calyx 
  end 
  of 
  an 
  apple. 
  

   Enlarged. 
  

  

  The 
  clover, 
  or 
  brown, 
  mite 
  (fig. 
  

   11:) 
  also 
  winters 
  in 
  the 
  ^gg 
  stage. 
  

   The 
  eggs 
  are 
  slightly 
  larger 
  and 
  

   rounder 
  than 
  those 
  of 
  the 
  Euro- 
  

   pean 
  red 
  mite 
  but 
  not 
  distinguish- 
  

   able 
  from 
  them 
  with 
  the 
  naked 
  

  

  