﻿ORCHL\RD 
  INSECTS 
  PACIFIC 
  NORTHWEST 
  

  

  27 
  

  

  are 
  deposited 
  on 
  the 
  leaves, 
  and 
  

   there 
  are 
  probably 
  two 
  or 
  more 
  

   generations 
  annually. 
  Fair 
  con- 
  

   trol 
  may 
  be 
  effected 
  with 
  three- 
  

   fourths 
  pint 
  of 
  nicotine 
  sulfate 
  to 
  

   100 
  gallons 
  of 
  water, 
  to 
  which 
  is 
  

   added 
  some 
  soap 
  or 
  spreader. 
  ( 
  See 
  

   Caution, 
  p. 
  60.) 
  The 
  underside 
  of 
  

   the 
  leaves 
  must 
  be 
  sprayed 
  thor- 
  

   oughly. 
  

  

  Apple 
  Leaf 
  Miners 
  

  

  In 
  western 
  Oregon 
  and 
  in 
  the 
  

   Hood 
  Kiver 
  Valley 
  the 
  apple 
  leaf 
  

   miner 
  may 
  be 
  found 
  in 
  apple 
  leaves 
  

   and 
  also 
  in 
  leaves 
  of 
  the 
  wild 
  haw- 
  

   thorn. 
  It 
  constructs 
  blotchlike 
  

   mines 
  in 
  the 
  leaf 
  (fig. 
  33) 
  between 
  

  

  Figure 
  33. 
  — 
  Apple 
  leaf 
  injured 
  by 
  the 
  

   apple 
  leaf 
  miner. 
  (Photograph 
  fur- 
  

   nished 
  by 
  Oregon 
  Agricultural 
  Experi- 
  

   ment 
  Station.) 
  

  

  the 
  large 
  veins 
  and 
  causes 
  the 
  leaf 
  

   to 
  become 
  somewhat 
  misshapen. 
  

   The 
  adult 
  is 
  a 
  very 
  small, 
  silvery 
  

   moth 
  that 
  lays 
  eggs 
  on 
  the 
  leaves. 
  

   The 
  young 
  worm 
  burrows 
  between 
  

   the 
  upper 
  and 
  lower 
  leaf 
  surfaces, 
  

  

  forming 
  the 
  mine. 
  When 
  full 
  

   grown 
  it 
  pupates 
  within 
  the 
  mine, 
  

   and 
  the 
  moth 
  emerges 
  soon 
  after. 
  

   There 
  are 
  probably 
  two 
  broods 
  in 
  

   a 
  season. 
  In 
  the 
  fall 
  the 
  worms 
  

   make 
  silken 
  hibernacula 
  in 
  the 
  

   mines, 
  where 
  they 
  spend 
  the 
  win- 
  

   ter 
  in 
  the 
  fallen 
  leaves. 
  

  

  The 
  apple 
  leaf 
  trumpet 
  miner 
  

   sometimes 
  causes 
  a 
  trumpet- 
  

   shaped 
  injury 
  on 
  apple 
  foliage 
  in 
  

   western 
  Oregon. 
  These 
  pests 
  are 
  

   of 
  minor 
  importance. 
  Any 
  clean- 
  

   ing 
  up 
  or 
  cultivation 
  that 
  destroys 
  

   or 
  buries 
  the 
  leaves 
  late 
  in 
  the 
  fall 
  

   would 
  prevent 
  many 
  of 
  the 
  moths 
  

   from 
  emerging 
  the 
  

   spring. 
  

  

  following 
  

  

  Apple 
  and 
  Thorn 
  Skeletonizer 
  

  

  Another 
  larva 
  that 
  injures 
  the 
  

   foliage 
  of 
  apple 
  and 
  pear 
  in 
  the 
  

   western 
  parts 
  of 
  Oregon 
  and 
  

   Washington 
  is 
  the 
  apple 
  and 
  

   thorn 
  skeletonizer. 
  It 
  also 
  feeds 
  

   on 
  cherry 
  and 
  hawthorn. 
  The 
  

   adult 
  is 
  a 
  small, 
  dark-brown 
  moth, 
  

   which 
  hibernates 
  and 
  deposits 
  

   eggs 
  early 
  in 
  the 
  spring. 
  The 
  

   small 
  caterpillars 
  feed 
  on 
  the 
  un- 
  

   der 
  sides 
  of 
  leaves 
  first 
  ; 
  later 
  they 
  

   feed 
  on 
  the 
  upper 
  surfaces 
  and 
  

   construct 
  shelters 
  by 
  drawing 
  the 
  

   leaves 
  together 
  with 
  silk. 
  The 
  

   injured 
  leaf 
  becomes 
  a 
  mass 
  of 
  

   webbing 
  and 
  frass. 
  There 
  are 
  

   several 
  generations 
  in 
  a 
  year. 
  

   Spraying 
  the 
  trees 
  with 
  lead 
  ar- 
  

   senate 
  or 
  DDT 
  as 
  for 
  other 
  leaf- 
  

   feeding 
  insects 
  is 
  an 
  effective 
  

   means 
  of 
  control. 
  

  

  Pear-Slug 
  

  

  The 
  pear-slug 
  feeds 
  on 
  the 
  fo- 
  

   liage 
  of 
  pear 
  and 
  cherry 
  trees, 
  

   skeletonizing 
  the 
  leaves 
  by 
  eating 
  

   the 
  upper 
  surfaces 
  (fig. 
  34). 
  The 
  

   larvae 
  are 
  slimy 
  and 
  sluglike 
  in 
  

   appearance, 
  olive 
  green 
  or 
  almost 
  

   black, 
  and 
  about 
  one-half 
  inch 
  

   long 
  when 
  full-grown. 
  When 
  

   they 
  are 
  numerous 
  the 
  whole 
  tree 
  

   becomes 
  brown, 
  as 
  though 
  swept 
  

  

  