﻿ORCHL\RD 
  IXSECTS 
  PACIFIC 
  XORTH^'EST 
  

  

  19 
  

  

  tive 
  at 
  any 
  time 
  during 
  the 
  winter 
  

   when 
  temperatures 
  are 
  above 
  40° 
  

   F. 
  In 
  March 
  they 
  start 
  depositing 
  

   eggs 
  (fig. 
  22. 
  B) 
  in 
  the 
  small 
  

  

  Figure 
  22. 
  — 
  Pear 
  psylla: 
  A, 
  Adult; 
  B. 
  

   eggs; 
  C, 
  large 
  nymphs. 
  (Photograph 
  

   furnished 
  by 
  New 
  York 
  Agricultural 
  

   Experiment 
  Station.) 
  

  

  crevices 
  about 
  the 
  buds, 
  and 
  after 
  

   the 
  foliage 
  is 
  out 
  they 
  deposit 
  them 
  

   on 
  the 
  leaves. 
  Each 
  female 
  may 
  

   deposit 
  as 
  many 
  as 
  500 
  eggs. 
  

   These 
  are 
  small 
  and 
  elongated, 
  and 
  

   whitish 
  or 
  yellowish. 
  The}^ 
  hatch 
  

   in 
  10 
  to 
  30 
  days 
  and 
  the 
  young 
  

   nymphs 
  migrate 
  to 
  the 
  axils 
  of 
  the 
  

   leaves 
  and 
  to 
  the 
  leaves 
  themselves 
  

   to 
  feed. 
  The 
  nymphs 
  (fig. 
  22, 
  C) 
  

   are 
  yellowish 
  and 
  flattened, 
  and 
  

   soon 
  cover 
  themselves 
  with 
  drop- 
  

   lets 
  of 
  honeydew. 
  which 
  they 
  

   secrete. 
  They 
  pass 
  through 
  five 
  

   immature 
  stages, 
  becoming 
  green- 
  

   ish 
  as 
  they 
  grow 
  larger, 
  and 
  finally 
  

   brownish-black 
  in 
  the 
  last, 
  or 
  

   "hard-shell."' 
  stage. 
  Often 
  these 
  

   "hard-shells-" 
  congregate 
  in 
  large 
  

   numbers 
  on 
  the 
  water 
  sprouts 
  and 
  

   other 
  tender 
  growth. 
  There 
  are 
  

   at 
  least 
  four 
  broods 
  a 
  year. 
  The 
  

   adults 
  deposit 
  eggs 
  almost 
  entirely 
  

  

  on 
  the 
  foliage 
  during 
  the 
  summer, 
  

   most 
  of 
  them 
  on 
  the 
  under 
  surface 
  

   along 
  the 
  midrib. 
  

  

  CONTROL 
  

  

  An 
  application 
  of 
  oil 
  emulsion, 
  

   as 
  used 
  for 
  the 
  San 
  Jose 
  scale, 
  in 
  

   the 
  early 
  spring: 
  when 
  the 
  trees 
  are 
  

   still 
  dormant 
  kills 
  many 
  of 
  the 
  

   adults 
  and 
  their 
  eggs, 
  and 
  usually 
  

   prevents 
  a 
  summer 
  infestation 
  

   from 
  developing 
  before 
  July. 
  The 
  

   summer 
  broods 
  may 
  be 
  controlled 
  

   readily 
  with 
  one 
  of 
  the 
  following 
  

   spraj's 
  (quantities 
  for 
  100 
  gallons 
  

   of 
  spray) 
  : 
  

  

  Nicotine 
  sulfate 
  three-fourths 
  

  

  pint 
  plus 
  summer-oil 
  emulsion 
  

  

  2 
  quarts. 
  

   Rotenone 
  (1 
  percent) 
  1 
  pound 
  

  

  plus 
  summer-oil 
  emulsion 
  2 
  

  

  quarts. 
  

   Parathion 
  (15 
  percent) 
  one 
  -half 
  

  

  pound. 
  

   Toxaphene 
  (50 
  percent 
  water- 
  

  

  miscible) 
  I14 
  pints. 
  

  

  Parathion 
  and 
  toxaphene 
  should 
  

   not 
  be 
  used 
  with 
  oil. 
  (See 
  Cau- 
  

   tions, 
  p. 
  59.) 
  All 
  these 
  insecticides 
  

   except 
  the 
  nicotine 
  will 
  also 
  con- 
  

   trol 
  any 
  mites 
  that 
  may 
  be 
  on 
  the 
  

   trees. 
  One 
  or 
  two 
  thorough 
  appli- 
  

   cations 
  should 
  suffice 
  for 
  the 
  sea- 
  

   son. 
  Dusting 
  is 
  less 
  effective 
  than 
  

   spraying. 
  

  

  Treehoppers 
  

  

  Young 
  orchards 
  containing 
  al- 
  

   falfa 
  or 
  clover 
  cover 
  crops 
  are 
  sub- 
  

   ject 
  to 
  the 
  attacks 
  of 
  several 
  

   species 
  of 
  treehoppers, 
  the 
  most 
  

   injurious 
  being 
  the 
  buffalo 
  tree- 
  

   hopper, 
  the 
  green 
  clover 
  treehop- 
  

   per. 
  and 
  the 
  dark-colored 
  tree- 
  

   hopper 
  (fig. 
  23) 
  . 
  The 
  injury 
  con- 
  

   sists 
  of 
  wounds 
  and 
  scars 
  made 
  by 
  

   the 
  female 
  when 
  laj'ing 
  her 
  eggs 
  

   in 
  the 
  bark 
  of 
  the 
  trees 
  (fig. 
  21). 
  

   The 
  female 
  cuts 
  slits, 
  roughened 
  

   and 
  ragged 
  or 
  clean-cut, 
  with 
  her 
  

   ovipositor, 
  the 
  type 
  of 
  injur}' 
  de- 
  

   pending 
  on 
  the 
  species. 
  The 
  in- 
  

   jury 
  rarely 
  extends 
  more 
  than 
  6 
  or 
  

   8 
  feet 
  above 
  the 
  gi'ound, 
  and 
  young 
  

  

  