﻿the 
  shortness 
  of 
  the 
  legs. 
  The 
  young 
  larval 
  forms, 
  appearing 
  during 
  

   the 
  latter 
  part 
  of 
  April 
  and 
  the 
  first 
  days 
  of 
  May, 
  move 
  easily 
  and 
  

   with 
  considerable 
  rapidity. 
  

  

  In 
  its 
  zoological 
  relations, 
  the 
  insect 
  belongs 
  to 
  the 
  order 
  Hemip- 
  

   tera, 
  family 
  Aphniida- 
  (plant-lice) 
  . 
  It 
  is 
  peculiar 
  to 
  North 
  America, 
  

   so 
  far 
  as 
  known. 
  The 
  insects 
  of 
  this 
  order 
  are 
  easily 
  recognized 
  by 
  

   their 
  sucking 
  beak, 
  and 
  it 
  is 
  by 
  this 
  beak 
  that 
  C. 
  iiinicorticis 
  causes 
  

   injury 
  to 
  the 
  pine. 
  After 
  a 
  short 
  period 
  of 
  active 
  movement 
  imme- 
  

   diately 
  following 
  the 
  time 
  of 
  hatching, 
  the 
  young 
  larvte 
  insert 
  their 
  

   beaks 
  into 
  the 
  bark, 
  and 
  begin 
  sucking 
  the 
  sap 
  of 
  the 
  tree. 
  As 
  there 
  

   are 
  immense 
  numbers 
  of 
  the 
  larvje 
  the 
  effect 
  is 
  soon 
  noticeable 
  in 
  

   a 
  marked^retardation 
  of 
  the 
  growth 
  of 
  the 
  tree, 
  and 
  sometimes 
  in 
  its 
  

   death. 
  Their 
  presence 
  causes 
  a 
  lessened 
  yearly 
  growth, 
  both 
  in 
  

   diameter 
  and 
  height: 
  the 
  leaves 
  are 
  thinner 
  and 
  shorter, 
  often 
  tinged 
  

   with 
  yellow, 
  and 
  the 
  limbs 
  are 
  more 
  slender 
  than 
  is 
  natural. 
  To 
  

   these 
  results, 
  particularly 
  bad 
  in 
  an 
  ornamental 
  tree, 
  must 
  be 
  added 
  

   the 
  disagreeable 
  appearance 
  of 
  the 
  sticky 
  white 
  secretion, 
  which 
  

   stains 
  whatever 
  it 
  touches. 
  Finally, 
  when' 
  the 
  injury 
  is 
  at 
  its 
  worst 
  

   the 
  lower 
  limbs 
  die 
  and 
  fall 
  away, 
  leaving 
  unsightly 
  scars, 
  and 
  ex- 
  

   hibiting 
  in 
  all 
  its 
  ugliness 
  the 
  spotted, 
  striped, 
  diseased 
  trunk, 
  

   capped 
  with 
  a 
  small 
  and 
  sickly 
  crown 
  of 
  branches 
  at 
  its 
  top. 
  When 
  

   an 
  ornamental 
  tree 
  has 
  reached 
  this 
  condition 
  its 
  death 
  is 
  as 
  certain 
  

   as 
  it 
  is 
  desirable. 
  

  

  ECONOMIC 
  IMPORTANCE 
  AND 
  GEOGRAPHICAL 
  DISTRIBI:TI0N. 
  

  

  Tnder 
  ordinary 
  conditions 
  it 
  is 
  not 
  probable 
  that 
  this 
  Chermes 
  is 
  

   able 
  to 
  kill 
  the 
  tree 
  outright. 
  There 
  are 
  a 
  number 
  of 
  insects 
  (some 
  

   of 
  which 
  are 
  mentioned 
  further 
  on 
  in 
  this 
  paper) 
  that 
  find 
  the 
  

   Chermes 
  quite 
  as 
  good 
  food 
  as 
  the 
  Chermes 
  does 
  the 
  pine. 
  Usually 
  

   these 
  enemies, 
  taken 
  in 
  connection 
  with 
  climatic 
  checks, 
  prevent 
  an 
  

   attack 
  from 
  being 
  absolutely 
  fatal, 
  but 
  seldom 
  or 
  never 
  can 
  do 
  more. 
  

   In 
  the 
  grove 
  referred 
  to 
  the 
  injury 
  has 
  been 
  continuous 
  for 
  several 
  

   years 
  and 
  the 
  appearance 
  of 
  the 
  trees 
  presages 
  their 
  final 
  destruction. 
  

   A 
  few 
  trees 
  separate 
  from 
  the 
  grove 
  show 
  a 
  much 
  less 
  virulent 
  attack, 
  

   but 
  the 
  injury 
  is 
  still 
  quite 
  apparent. 
  In 
  general 
  the 
  Chermes 
  seems 
  

   to 
  be 
  able 
  to 
  maintain 
  itself 
  against 
  its 
  enemies, 
  and 
  to 
  take 
  full 
  

   advantage 
  of 
  any 
  favoring 
  circumstances 
  which 
  may 
  disturb 
  for 
  a 
  

   time 
  the 
  ''balance 
  of 
  power" 
  in 
  its 
  life 
  relations. 
  The 
  rapid 
  multi- 
  

   plication 
  of 
  plant-lice— 
  most 
  of 
  which, 
  as 
  is 
  well 
  known, 
  produce 
  

   .several 
  or 
  many 
  generations 
  during 
  the 
  season— 
  enables 
  them 
  to 
  take 
  

   immediate 
  advantage 
  of 
  any 
  cessation 
  or 
  weakening 
  of 
  opposition 
  on 
  

   the 
  part 
  of 
  tlieir 
  natural 
  enemies, 
  however 
  slight 
  it 
  may 
  be. 
  This 
  

   peculiarity 
  may 
  at 
  any 
  time 
  elevate 
  Chermes 
  pinicorticis 
  from 
  the 
  

   rather 
  subordinate 
  position 
  it 
  now 
  occupies 
  economically 
  to 
  one 
  of 
  

   prime 
  importance 
  to 
  those 
  who 
  possess 
  or 
  admire 
  any 
  of 
  the 
  species 
  

   of 
  pine 
  which 
  it 
  attacks. 
  

  

  The 
  latter 
  consideration 
  makes 
  its 
  geographical 
  distribution 
  a 
  

   matter 
  of 
  interest. 
  Presumably 
  the 
  original 
  description 
  by 
  Dr. 
  

   Fitch 
  was 
  made 
  from 
  specimens 
  taken 
  in 
  New 
  York, 
  and 
  his 
  state- 
  

   ments 
  indicate 
  that 
  the 
  attack 
  was 
  severe. 
  Dr. 
  Shinier 
  reported 
  it 
  

  

  