﻿10 
  

  

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

  

  in 
  June. 
  At 
  that 
  time 
  they 
  are 
  

   about 
  three-fourths 
  inch 
  long 
  and 
  

   green 
  with 
  black 
  heads. 
  They 
  

   transform 
  to 
  brown 
  pupae 
  in 
  the 
  

   rolled-up 
  leaves, 
  and 
  the 
  moths 
  

   (fig. 
  10, 
  B) 
  emerge 
  about 
  10 
  or 
  12 
  

   days 
  later. 
  They 
  are 
  a 
  little 
  larger 
  

   than 
  codling 
  moths, 
  the 
  expanded 
  

   wings 
  measuring 
  about 
  three- 
  

   fourths 
  inch 
  across, 
  and 
  are 
  cin- 
  

   namon 
  brown, 
  with 
  two 
  or 
  three 
  

   light-yellowish 
  markings. 
  

  

  CONTROL 
  

  

  The 
  most 
  effective 
  means 
  of 
  con- 
  

   trolling 
  the 
  leaf 
  roller 
  is 
  to 
  apply 
  

   an 
  oil 
  spray 
  in 
  the 
  spring 
  before 
  

   the 
  eggs 
  have 
  hatched. 
  Any 
  of 
  the 
  

   emulsions 
  that 
  are 
  satisfactory 
  for 
  

   scale 
  control 
  may 
  be 
  used 
  for 
  this 
  

   purpose. 
  Light 
  infestations 
  may 
  

   be 
  treated 
  with 
  an 
  emulsion 
  con- 
  

   taining 
  4 
  percent 
  of 
  oil, 
  but 
  for 
  

   serious 
  outbreaks, 
  when 
  large 
  

   numbers 
  of 
  eggs 
  are 
  on 
  the 
  trees, 
  

   the 
  emulsion 
  should 
  contain 
  5 
  or 
  6 
  

   percent 
  of 
  oil. 
  Spraying 
  should 
  

   be 
  done 
  during 
  the 
  first 
  period 
  of 
  

   settled 
  mild 
  weather 
  and 
  before 
  

   the 
  eggs 
  have 
  begun 
  to 
  hatch. 
  It 
  

   should 
  not 
  be 
  clone 
  just 
  before 
  a 
  

   rain 
  or 
  when 
  the 
  temperature 
  is 
  

   likely 
  to 
  drop 
  below 
  25° 
  F. 
  within 
  

   a 
  few 
  days. 
  

  

  For 
  severe 
  infestations 
  that 
  

   have 
  not 
  been 
  suiRciently 
  con- 
  

   trolled 
  by 
  this 
  means, 
  a 
  lead 
  arsen- 
  

   ate 
  or 
  DDT 
  spray 
  may 
  be 
  applied 
  

   as 
  soon 
  as 
  the 
  buds 
  begin 
  to 
  sepa- 
  

   rate 
  in 
  the 
  clusters. 
  To 
  make 
  100 
  

   gallons 
  of 
  spray 
  4 
  pounds 
  of 
  lead 
  

   arsenate 
  or 
  2 
  pounds 
  of 
  50-percent 
  

   DDT 
  wettable 
  powder 
  is 
  used. 
  

  

  Orchard 
  Mites 
  

  

  Orchard 
  mites 
  do 
  great 
  damage 
  

   to 
  fruit 
  trees, 
  much 
  of 
  it 
  difficult 
  

   to 
  measure. 
  They 
  feed 
  by 
  with- 
  

   drawing 
  the 
  contents 
  of 
  the 
  leaf 
  

   cells, 
  including 
  the 
  chlorophyll, 
  

   thus 
  causing 
  a 
  whitening 
  or 
  mot- 
  

   tling 
  of 
  the 
  leaves, 
  which 
  finally 
  

   become 
  browned 
  or 
  bronzed. 
  In 
  

  

  nonirrigated 
  orchards 
  complete 
  or 
  

   partial 
  defoliation 
  frequently 
  re- 
  

   sults. 
  However, 
  any 
  foliage 
  in- 
  

   jury 
  reduces 
  the 
  vitality 
  of 
  the 
  

   tree, 
  and 
  consequently 
  the 
  size 
  of 
  

   the 
  fruit, 
  even 
  if 
  it 
  does 
  not 
  cause 
  

   the 
  leaves 
  to 
  drop 
  off. 
  

  

  LIFE 
  HISTORY 
  

  

  Four 
  important 
  species 
  of 
  mites 
  

   infest 
  orchards 
  in 
  the 
  Pacific 
  

   NortliAvest. 
  Two 
  are 
  of 
  European 
  

   origin 
  and 
  the 
  others 
  are 
  native. 
  

  

  Figure 
  11. 
  — 
  Pacific 
  mite: 
  A, 
  Egg; 
  B, 
  adult. 
  

   Greatly 
  enlarged. 
  

  

  The 
  Pacific 
  mite 
  (fig. 
  11, 
  B) 
  

   causes 
  more 
  injury 
  than 
  the 
  others, 
  

   and 
  in 
  some 
  orchards 
  it 
  is 
  the 
  most 
  

   serious 
  pest 
  the 
  grower 
  has 
  to 
  deal 
  

   with. 
  The 
  Avebbing 
  it 
  spins 
  often 
  

   collects 
  dust 
  and 
  gives 
  the 
  foliage 
  

   a 
  dry 
  and 
  dusty 
  appearance. 
  

   This 
  species 
  winters 
  as 
  an 
  adult 
  

   in 
  leaves 
  and 
  trash 
  on 
  the 
  ground, 
  

   and 
  in 
  mild 
  winters 
  some 
  individ- 
  

   uals 
  are 
  able 
  to 
  survive 
  on 
  the 
  

   trees 
  in 
  crevices 
  of 
  the 
  bark. 
  In 
  

   the 
  spring 
  the 
  mites 
  migrate 
  into 
  

   the 
  trees, 
  first 
  attacking 
  the 
  foli- 
  

  

  