﻿12 
  

  

  CIRCULAR 
  2 
  7 
  0, 
  U. 
  S. 
  DEPARTMENT 
  OF 
  AGRICULTURE 
  

  

  eye. 
  They 
  hatch 
  about 
  a 
  week 
  

   earlier; 
  otherwise 
  the 
  habits 
  and 
  

   life 
  history 
  of 
  the 
  two 
  species 
  are 
  

   much 
  alike. 
  The 
  brown 
  mites 
  spin 
  

   no 
  webbing. 
  They 
  congregate 
  in 
  

   roughened 
  places 
  on 
  the 
  twigs 
  and 
  

   branches 
  during 
  the 
  day, 
  and 
  mi- 
  

   grate 
  to 
  the 
  leaves 
  at 
  night 
  to 
  feed. 
  

   This 
  habit 
  of 
  feeding 
  at 
  night 
  and 
  

   the 
  lack 
  of 
  webbing 
  make 
  them 
  in- 
  

  

  Figure 
  14. 
  — 
  Adult 
  clover 
  mite. 
  Greatly 
  

   enlarged. 
  

  

  conspicuous, 
  and 
  usually 
  the 
  whit- 
  

   ening 
  of 
  the 
  leaves 
  caused 
  by 
  their 
  

   feeding 
  is 
  the 
  first 
  evidence 
  of 
  

   their 
  presence. 
  The 
  adults 
  are 
  

   dull 
  reddish 
  or 
  greenish, 
  and 
  are 
  

   flatter 
  and 
  have 
  longer 
  legs 
  than 
  

   those 
  of 
  the 
  European 
  red 
  mite. 
  

   They 
  are 
  found 
  on 
  deciduous 
  fruit 
  

   trees 
  and 
  on 
  clover 
  and 
  other 
  for- 
  

   age 
  crops. 
  

  

  ^; 
  CONTROL 
  

  

  i.. 
  The 
  method 
  of 
  controlling 
  or- 
  

   chard 
  mites 
  depends 
  somewhat 
  on 
  

   the 
  species. 
  Irrigation, 
  where 
  

   practiced, 
  is 
  an 
  important 
  factor 
  

   in 
  reducing 
  mite 
  injury, 
  and 
  in 
  

   facilitating 
  control 
  by 
  spraying. 
  

   Thrifty, 
  adequately 
  irrigated 
  trees 
  

   are 
  damaged 
  less 
  by 
  mites 
  than 
  

   are 
  trees 
  that 
  are 
  dry 
  and 
  in 
  poor 
  

   condition. 
  Defoliation, 
  which 
  is 
  

   always 
  serious 
  if 
  it 
  occurs 
  before 
  

  

  September, 
  may 
  force 
  the 
  trees 
  to 
  

   send 
  out 
  new 
  leaves 
  or 
  blossoms 
  in 
  

   the 
  fall 
  and 
  materially 
  reduce 
  the 
  

   following 
  year's 
  crop. 
  It 
  also 
  

   affects 
  the 
  fruit 
  buds 
  and 
  the 
  size 
  

   of 
  the 
  current 
  crop. 
  

  

  Spraying 
  or 
  dusting 
  is 
  practi- 
  

   cally 
  the 
  only 
  direct 
  means 
  of 
  con- 
  

   trolling 
  orchard 
  mites. 
  It 
  must 
  

   be 
  done 
  before 
  July 
  to 
  be 
  of 
  much 
  

   value. 
  Dormant-season 
  sprays 
  

   containing 
  4 
  percent 
  of 
  oil 
  emul- 
  

   sion, 
  as 
  used 
  for 
  scale 
  insects 
  or 
  for 
  

   the 
  leaf 
  roller, 
  destroy 
  the 
  over- 
  

   wintering 
  eggs 
  of 
  the 
  European 
  

   red 
  mite 
  and 
  the 
  brown 
  mite. 
  A 
  

   mixture 
  containing 
  2 
  percent 
  of 
  

   oil 
  and 
  3 
  percent 
  of 
  liquid 
  lime- 
  

   sulfur 
  is 
  also 
  effective. 
  The 
  spray 
  

   should 
  be 
  applied 
  before 
  March 
  15, 
  

   as 
  the 
  trees 
  are 
  sometimes 
  injured 
  

   by 
  late-dormant 
  sprays. 
  Lime- 
  

   sulfur 
  alone 
  is 
  relatively 
  ineffec- 
  

   tive 
  against 
  these 
  eggs. 
  Sprays 
  of 
  

   lime-sulfur, 
  however, 
  made 
  with 
  2 
  

   or 
  3 
  gallons 
  (see 
  table 
  1, 
  p. 
  60) 
  to 
  

   100 
  gallons 
  of 
  water, 
  as 
  used 
  for 
  

   combating 
  apple 
  powdery 
  mildew 
  

   or 
  apple 
  scab, 
  are 
  valuable 
  in 
  de- 
  

   stroying 
  young 
  mites. 
  These 
  

   sprays 
  should 
  be 
  applied 
  just 
  be- 
  

   fore 
  the 
  blossoms 
  open 
  and 
  again 
  

   as 
  a 
  calyx 
  application. 
  

  

  Neither 
  the 
  dormant-season 
  

   sprays 
  nor 
  sprays 
  used 
  for 
  con- 
  

   trolling 
  mildew 
  can 
  be 
  depended 
  

   on 
  to 
  control 
  the 
  mites 
  for 
  the 
  en- 
  

   tire 
  season. 
  However, 
  orchard 
  

   mites 
  can 
  be 
  controlled 
  with 
  sum- 
  

   mer 
  sprays, 
  even 
  though 
  the 
  ear- 
  

   lier 
  applications 
  have 
  not 
  been 
  

   made. 
  They 
  are 
  the 
  only 
  sprays 
  

   that 
  are 
  effective 
  against 
  the 
  

   Pacific 
  mite 
  and 
  the 
  Willamette 
  

   mite, 
  since 
  these 
  species 
  are 
  usually 
  

   not 
  on 
  the 
  trees 
  when 
  the 
  earlier 
  

   sprays 
  are 
  applied. 
  

  

  A 
  number 
  of 
  chemicals 
  that 
  can 
  

   be 
  used 
  in 
  summer 
  sprays 
  are 
  

   toxic 
  to 
  orchard 
  mites. 
  Chief 
  

   among 
  these 
  are 
  parathion 
  and 
  

   rotenone. 
  Either 
  of 
  these 
  mate- 
  

   rials 
  may 
  be 
  added 
  to 
  DDT 
  ap- 
  

  

  