﻿ORCHARD 
  INSECTS 
  PACIFIC 
  NORTHWEST 
  

  

  23 
  

  

  the 
  fore 
  part 
  of 
  the 
  body 
  broad 
  and 
  

   flat 
  (fig. 
  29, 
  B). 
  The 
  beetles 
  

   emerge 
  in 
  the 
  spring 
  and 
  lay 
  eggs 
  

   on 
  the 
  tree 
  trunks, 
  preferably 
  in 
  

   the 
  sun. 
  The 
  young 
  borers 
  burrow 
  

   into 
  the 
  bark 
  and 
  require 
  a 
  year 
  or 
  

   more 
  for 
  complete 
  development. 
  

   Both 
  species 
  are 
  native 
  American 
  

   insects. 
  

  

  Trees 
  should 
  be 
  kept 
  in 
  a 
  healthy 
  

   condition, 
  as 
  the 
  young 
  borers 
  are 
  

   unable 
  to 
  thrive 
  in 
  vigorous 
  trees 
  

   with 
  strong-flowing 
  sap. 
  If 
  the 
  

   trunks 
  of 
  young 
  trees 
  -are 
  protec- 
  

   ted 
  with 
  whitewash, 
  or 
  if 
  a 
  board 
  

   or 
  stave 
  is 
  placed 
  so 
  that 
  it 
  will 
  

   shade 
  the 
  trunk, 
  danger 
  of 
  injury 
  

   will 
  be 
  reduced. 
  

  

  Shot-Hole 
  Borer 
  

  

  In 
  the 
  coastal 
  area 
  small, 
  round 
  

   holes, 
  looking 
  like 
  shot 
  holes, 
  are 
  

   sometimes 
  found 
  in 
  the 
  trunks 
  of 
  

   apple 
  and 
  pear 
  trees. 
  They 
  are 
  

   made 
  by 
  a 
  small, 
  black 
  scolytid 
  

   beetle 
  known 
  in 
  the 
  Pacific 
  North- 
  

   west 
  as 
  a 
  shot-hole 
  borer. 
  Usually 
  

   only 
  unhealthy 
  trees 
  are 
  attacked. 
  

  

  For 
  further 
  information 
  about 
  

   these 
  insects, 
  see 
  page 
  51. 
  

  

  Bronze 
  Apple 
  Tree 
  Weevil 
  

  

  The 
  bronze 
  apple 
  tree 
  weevil 
  

   attacks 
  weakened 
  apple 
  and 
  prune 
  

   trees, 
  making 
  several 
  small 
  holes 
  

   in 
  a 
  patch 
  in 
  the 
  bark. 
  These 
  

   holes 
  are 
  egg 
  punctures, 
  and 
  the 
  

   grubs 
  hatching 
  from 
  the 
  eggs 
  feed 
  

   beneath 
  the 
  bark, 
  causing 
  a 
  

   sunken, 
  discolored 
  area 
  about 
  the 
  

   size 
  of 
  a 
  silver 
  dollar. 
  The 
  adult 
  

   beetles, 
  which 
  are 
  small, 
  bronzy 
  or 
  

   black, 
  and 
  have 
  snouts, 
  emerge 
  the 
  

   following 
  spring. 
  Attacks 
  of 
  this 
  

   weevil 
  may 
  be 
  prevented 
  and 
  con- 
  

   trolled 
  in 
  the 
  manner 
  described 
  

   for 
  shot-hole 
  borers. 
  

  

  Pear 
  Thrips 
  

  

  The 
  pear 
  thrips 
  is 
  found 
  on 
  

   pears, 
  but 
  in 
  the 
  Pacific 
  Northwest 
  

   it 
  is 
  more 
  serious 
  as 
  a 
  prune 
  pest, 
  

   and 
  it 
  is 
  therefore 
  discussed 
  under 
  

  

  that 
  heading 
  (p. 
  39) 
  . 
  The 
  recom- 
  

   mendations 
  given 
  there 
  also 
  apply 
  

   to 
  pear 
  trees. 
  

  

  Apple 
  Leafhoppers 
  

  

  The 
  leafhoppers, 
  like 
  orchard 
  

   mites, 
  are 
  sucking 
  insects 
  feeding 
  

   exclusively 
  on 
  the 
  foliage 
  of 
  apple 
  

   trees. 
  They 
  withdraw 
  the 
  chlo- 
  

   rophyll 
  and 
  other 
  cell 
  contents, 
  

   leaving 
  the 
  foliage 
  with 
  a 
  

   whitened 
  or 
  mottled 
  appearance. 
  

   Slight 
  foliage 
  injury 
  by 
  leafhop- 
  

   pers 
  and 
  mites 
  is 
  of 
  no 
  conse- 
  

   quence, 
  but 
  as 
  soon 
  as 
  the 
  foliage 
  

   is 
  reduced 
  below 
  the 
  amount 
  re- 
  

   quired 
  for 
  the 
  crop, 
  the 
  fruit 
  and 
  

   buds 
  are 
  directly 
  affected. 
  The 
  

   fruit 
  fails 
  to 
  reach 
  normal 
  size 
  

   and 
  the 
  buds 
  are 
  weakened 
  so 
  that 
  

   they 
  may 
  not 
  set 
  fruit 
  the 
  next 
  

   season. 
  It 
  is 
  therefore 
  important 
  

   to 
  guard 
  against 
  extensive 
  injury. 
  

  

  LIFE 
  HISTORY 
  

  

  Two 
  species 
  of 
  leafhoppers 
  are 
  

   prevalent 
  in 
  the 
  Pacific 
  North- 
  

   west, 
  both 
  native 
  to 
  the 
  United 
  

   States. 
  The 
  more 
  common 
  and 
  

   important 
  of 
  these 
  is 
  the 
  rose 
  leaf- 
  

   hopper, 
  a 
  slender, 
  active, 
  whitish 
  

   insect 
  about 
  one-eighth 
  inch 
  long. 
  

   It 
  winters 
  in 
  the 
  ^gg 
  stage 
  in 
  the 
  

   bark 
  of 
  the 
  trees. 
  The 
  eggs 
  hatch 
  

   in 
  April 
  and 
  early 
  in 
  May, 
  and 
  the 
  

   small 
  white 
  hoppers 
  begin 
  to 
  feed 
  

   at 
  once 
  on 
  the 
  new 
  foliage, 
  remain- 
  

   ing 
  in 
  the 
  pubescence 
  of 
  the 
  

   underside 
  of 
  the 
  leaves. 
  Growth 
  

   is 
  attained 
  in 
  3 
  to 
  6 
  weeks, 
  and 
  the 
  

   adults 
  live 
  for 
  2 
  months 
  or 
  more. 
  

   Eggs 
  are 
  laid 
  in 
  the 
  tissue 
  of 
  the 
  

   leaves 
  from 
  June 
  to 
  August, 
  and 
  

   hatch 
  in 
  about 
  a 
  month. 
  The 
  sec- 
  

   ond 
  brood 
  of 
  young 
  thus 
  appears 
  

   late 
  in 
  July 
  and 
  August, 
  and 
  

   adults 
  are 
  present 
  again 
  from 
  Au- 
  

   gust 
  to 
  November. 
  These 
  lay 
  

   wintering 
  eggs 
  in 
  the 
  bark, 
  where 
  

   they 
  appear 
  as 
  small 
  raised 
  blis- 
  

   ters. 
  

  

  The 
  apple 
  leafhopper 
  has 
  only 
  

   one 
  generation 
  a 
  year, 
  beginning 
  

  

  