﻿INJURIES 
  BY 
  THE 
  SCALE. 
  

  

  All 
  exposed 
  parts 
  of 
  the 
  foregoing 
  trees 
  and 
  shrubs, 
  including 
  

   bark, 
  leaf, 
  and 
  in 
  many 
  cases 
  even 
  the 
  fruit, 
  may 
  afford 
  it 
  lodgment 
  

   and 
  food. 
  Upon 
  the 
  bark 
  of 
  twig, 
  branch, 
  or 
  trunk 
  it 
  may 
  form, 
  

   when 
  abundant, 
  a 
  continuous 
  crust, 
  completely 
  concealing 
  the 
  sur- 
  

   face 
  with 
  a 
  dusky 
  or 
  grayish 
  scurfy 
  deposit 
  of 
  closely 
  packed 
  

   scales, 
  so 
  small 
  and 
  so 
  nearly 
  flat 
  that 
  even 
  the 
  observant 
  horticul- 
  

   turist 
  is 
  little 
  likely 
  to 
  recognize 
  them 
  as 
  scale 
  insects. 
  A 
  tree 
  so 
  

   infested 
  is 
  readily 
  seen 
  to 
  be 
  in 
  an 
  unthrifty 
  condition, 
  but 
  when 
  

   special 
  information 
  is 
  lacking 
  it 
  is 
  commonly 
  classed 
  simply 
  as 
  dis- 
  

   eased. 
  If 
  the 
  surface 
  be 
  rubbed 
  or 
  scraped, 
  however, 
  it 
  will 
  have 
  a 
  

   peculiar 
  greasy 
  feeling 
  under 
  the 
  finger, 
  and 
  a 
  yellowish 
  litiuid 
  may 
  

   be 
  detected, 
  produced 
  by 
  crushing 
  bodies 
  of 
  the 
  insects 
  still 
  living 
  

   beneath 
  the 
  scales. 
  

  

  •Examined 
  under 
  a 
  hand 
  lens 
  during 
  the 
  summer, 
  numbers 
  of 
  

   little 
  orange-colored 
  larvae 
  will 
  be 
  seen 
  running 
  about, 
  and 
  the 
  snowy 
  

   white 
  young 
  scale 
  will 
  be 
  interspersed 
  with 
  old 
  blackened 
  mature 
  

   scales. 
  Very 
  frequently 
  the 
  scale 
  has 
  a 
  marked 
  tendency 
  to 
  infest 
  

   the 
  extremities 
  of 
  the 
  branches 
  and 
  twigs. 
  This 
  is 
  particularly 
  

   noticeable 
  with 
  pear. 
  As 
  usually 
  found 
  on 
  peach, 
  the 
  scale 
  is 
  massed 
  

   often 
  more 
  densely 
  on 
  the 
  older 
  growth, 
  and 
  works 
  out 
  more 
  slowly 
  

   toward 
  the 
  new 
  wood. 
  

  

  '•The 
  San 
  Jose 
  scale 
  was 
  formerly 
  supposed 
  to 
  differ 
  from 
  all 
  

   others 
  in 
  the 
  peculiar 
  reddening 
  effect 
  which 
  it 
  produces 
  upon 
  the 
  

   skin 
  of 
  the 
  fruit 
  and 
  of 
  tender 
  twigs. 
  This, 
  however, 
  sometimes 
  

   occurs 
  with 
  other 
  scales, 
  but 
  is 
  a 
  particularly 
  characteristic 
  feature 
  

   of 
  this 
  insect, 
  and 
  renders 
  it 
  easy 
  to 
  distinguish. 
  The 
  encircling 
  

   band 
  of 
  reddish 
  discoloration 
  around 
  the 
  margin 
  of 
  each 
  female 
  scale 
  

   is 
  very 
  noticeable 
  on 
  fruit, 
  especially 
  pears. 
  Fruit 
  severely 
  attacked 
  

   becomes 
  distorted, 
  rough, 
  and 
  pitted, 
  frequently 
  cracking, 
  and 
  may 
  

   eventually 
  fall 
  prematurely 
  or 
  at 
  least 
  become 
  unmarketable. 
  

  

  "The 
  cambium 
  layer 
  of 
  young 
  twigs 
  where 
  the 
  scales 
  are 
  massed 
  

   together 
  is 
  usually 
  stained 
  deep 
  red 
  or 
  purplish, 
  and 
  when 
  the 
  scale 
  is 
  

   only 
  scatteringly 
  present 
  the 
  distinctive 
  purplish 
  ring 
  surrounding 
  

   each 
  is 
  almost 
  as 
  noticeable 
  on 
  young 
  twigs 
  as 
  on 
  fruit, 
  and 
  is 
  of 
  the 
  

   greatest 
  service 
  in 
  facilitating 
  the 
  inspection 
  of 
  trees 
  which 
  have 
  

   been 
  subject 
  to 
  possible 
  contagion. 
  The 
  almost 
  microscopic 
  young 
  

   scale 
  might 
  easily 
  elude 
  the 
  most 
  careful 
  search, 
  but 
  the 
  striking 
  

   circling 
  ring 
  makes 
  them 
  comparatively 
  conspicuous 
  objects 
  without 
  

   the 
  aid 
  of 
  a 
  glass. 
  

  

  "If 
  the 
  tree 
  survives 
  the 
  attack 
  the 
  infested 
  wood 
  eventually 
  be- 
  

   comes 
  knotty 
  and 
  irregular, 
  partly 
  from 
  the 
  sapping 
  of 
  the 
  juices 
  by 
  

   the 
  insect 
  and 
  also, 
  without 
  doubt, 
  largely 
  from 
  the 
  poisoning 
  of 
  the 
  

   .sap 
  of 
  the 
  cambium 
  layer 
  by 
  the 
  punctures 
  of 
  the 
  insect, 
  as 
  indicated 
  

   by 
  the 
  discoloration. 
  Young 
  peach 
  trees 
  will 
  ordinarily 
  survive 
  

   the 
  scale 
  only 
  two 
  or 
  three 
  years. 
  Pears 
  are 
  sometimes 
  killed 
  out- 
  

   right, 
  but 
  generally 
  maintain 
  a 
  feeble, 
  sickly 
  existence, 
  making 
  little 
  

   or 
  no 
  growth 
  for 
  a 
  somewhat 
  longer 
  period."* 
  

  

  * 
  "The 
  San 
  Jose 
  Scale: 
  its 
  Occurrences 
  in 
  the 
  United 
  States, 
  with 
  a 
  Full 
  Account 
  of 
  its 
  

   Life 
  History 
  and 
  the- 
  Remedies 
  tn 
  be 
  used 
  against 
  it." 
  Bull, 
  No. 
  3, 
  N. 
  S., 
  U. 
  S. 
  Dept, 
  Agrr., 
  

   Div. 
  Ent., 
  p. 
  15. 
  

  

  