﻿ORCHARD 
  INSECTS 
  PACIFIC 
  NORTHWEST 
  

  

  15 
  

  

  will 
  control 
  this 
  mite 
  if 
  the 
  under- 
  

   sides 
  of 
  the 
  leaves 
  are 
  sprayed 
  

   thoroughly. 
  

  

  Rosy 
  Apple 
  Aphid 
  

  

  The 
  rosy 
  apple 
  aphid 
  feeds 
  only 
  

   on 
  apple 
  and 
  on 
  its 
  alternate 
  sum- 
  

   mer 
  host, 
  the 
  plantain 
  or 
  ribo;rass. 
  

   It 
  curls 
  the 
  leaves, 
  particularly 
  

   those 
  on 
  the 
  fruit 
  spurs, 
  and 
  in- 
  

   fests 
  the 
  young 
  fruit, 
  causing 
  it 
  to 
  

   become 
  stunted 
  and 
  distorted 
  (fig. 
  

   16). 
  These 
  aphid 
  apples 
  do 
  not 
  

  

  Figure 
  16. 
  — 
  Apples 
  stunted 
  by 
  the 
  rosy 
  

   apple 
  aphid. 
  

  

  thin 
  out 
  normally 
  during 
  the 
  June 
  

   drop, 
  and 
  in 
  the 
  fall 
  clusters 
  of 
  

   them 
  are 
  often 
  conspicuous, 
  espe- 
  

   cially 
  on 
  the 
  lower 
  and 
  inner 
  parts 
  

   of 
  the 
  trees. 
  At 
  times 
  they 
  are 
  suf- 
  

   ficiently 
  numerous 
  to 
  cause 
  a 
  dis- 
  

   tinct 
  reduction 
  in 
  the 
  marketable 
  

   crop. 
  This 
  aphid 
  was 
  probably 
  

   introduced 
  from 
  Europe. 
  

  

  LIFE 
  HISTORY 
  

  

  The 
  rosy 
  apple 
  aphid 
  winters 
  in 
  

   the 
  egg 
  stage 
  on 
  apple 
  trees, 
  and 
  

   the 
  eggs 
  hatch 
  in 
  the 
  spring 
  when 
  

   the 
  buds 
  begin 
  to 
  swell. 
  The 
  

  

  young 
  start 
  feeding 
  in 
  the 
  unfold- 
  

   ing 
  fruit 
  buds, 
  causing 
  the 
  leaves 
  

   to 
  curl 
  as 
  they 
  develop. 
  Several 
  

   generations 
  of 
  aphids 
  are 
  pro- 
  

   duced 
  on 
  the 
  apple, 
  and 
  these 
  feed 
  

   on 
  the 
  leaves 
  and 
  the 
  fruit. 
  The 
  

   species 
  may 
  be 
  distinguished 
  by 
  

   its 
  purplish 
  or 
  rosy-brown 
  color 
  

   and 
  by 
  its 
  habit 
  of 
  curling 
  the 
  

   leaves 
  and 
  deforming 
  the 
  fruit. 
  

   As 
  the 
  weather 
  becomes 
  warmer, 
  

   brownish-green 
  winged 
  individ- 
  

   uals 
  develop 
  and 
  migrate 
  to 
  the 
  

   plantain. 
  Most 
  of 
  the 
  aphids 
  have 
  

   left 
  the 
  apple 
  trees 
  by 
  early 
  in 
  

   July. 
  They 
  do 
  not 
  migrate 
  to 
  

   other 
  apple 
  trees, 
  and 
  therefore 
  

   trees 
  not 
  bearing 
  winter 
  eggs 
  re- 
  

   main 
  free 
  of 
  infestation. 
  On 
  the 
  

   plantain 
  several 
  generations 
  of 
  

   yellowish-green 
  aphids 
  occur, 
  and 
  

   in 
  the 
  fall 
  winged 
  forms 
  again 
  de- 
  

   velop 
  and 
  fly 
  back 
  to 
  the 
  apple 
  

   trees, 
  where 
  they 
  produce 
  a 
  wing- 
  

   less 
  generation 
  of 
  aphids. 
  These 
  

   aphids 
  deposit 
  eggs 
  on 
  the 
  twigs, 
  

   in 
  the 
  axils 
  of 
  the 
  buds, 
  and 
  in 
  

   crevices 
  in 
  the 
  bark. 
  At 
  first 
  the 
  

   eggs 
  are 
  pale 
  green 
  but 
  later 
  they 
  

   become 
  shiny 
  black. 
  

  

  CONTROL 
  

  

  The 
  rosy 
  apple 
  aphid 
  should 
  be 
  

   controlled 
  before 
  the 
  leaves 
  have 
  

   been 
  curled, 
  as 
  it 
  is 
  difficult 
  to 
  ac- 
  

   complish 
  afterward. 
  A 
  spray 
  con- 
  

   taining 
  4 
  percent 
  of 
  oil 
  destroys 
  

   many 
  of 
  the 
  young 
  aphids 
  gath- 
  

   ered 
  on 
  the 
  buds 
  if 
  it 
  is 
  applied 
  

   just 
  after 
  the 
  eggs 
  have 
  hatched. 
  

   A 
  mixture 
  containing 
  2 
  percent 
  of 
  

   oil 
  enmlsion 
  and 
  3 
  percent 
  of 
  

   liquid 
  lime-sulfur, 
  applied 
  when 
  

   the 
  trees 
  are 
  still 
  dormant, 
  is 
  ef- 
  

   fective, 
  but 
  the 
  dormant-season 
  

   application 
  of 
  lime-sulfur 
  alone 
  is 
  

   less 
  effective. 
  Better 
  control 
  will 
  

   result 
  from 
  using 
  nicotine 
  sulfate 
  

   (40 
  percent 
  nicotine), 
  three- 
  

   fourths 
  pint 
  to 
  100 
  gallons 
  of 
  

   water, 
  in 
  combination 
  with 
  the 
  oil 
  

   emulsion 
  or 
  the 
  lime-sulfur. 
  This 
  

   application 
  must 
  be 
  completed 
  be- 
  

  

  