﻿SCALE 
  INSECTS 
  OF 
  IMPORTANCE 
  295 
  

  

  Recognition 
  of 
  scale 
  insects. 
  The 
  majority 
  of 
  farmers 
  and 
  fruit- 
  

   growers 
  experience 
  great 
  difficulty 
  in 
  distinguishing 
  between 
  the 
  various- 
  

   forms, 
  and 
  such 
  will 
  continue 
  to 
  be 
  the 
  case 
  for 
  some 
  time 
  to 
  come 
  ; 
  but 
  

   it 
  is 
  hoped 
  that 
  the 
  illustrations 
  accompanying 
  this 
  account 
  will 
  enable 
  

   the 
  non-scientific 
  man 
  to 
  identify 
  certain 
  of 
  these 
  vexatious 
  forms 
  with 
  

   some 
  approach 
  to 
  accuracy. 
  It 
  must 
  ever 
  be 
  borne 
  in 
  mind^ 
  however, 
  

   that, 
  in 
  attempting 
  to 
  identify 
  an 
  armored 
  scale 
  insect 
  by 
  external 
  appear- 
  

   ances, 
  we 
  are 
  not 
  studying 
  the 
  insect 
  itself 
  but 
  a 
  secretion 
  subject 
  to 
  con- 
  

   siderable 
  variation 
  as 
  a 
  result 
  of 
  climatic 
  and 
  other 
  external 
  influences. 
  

   Scale 
  insects 
  occurring 
  on 
  trees 
  near 
  a 
  railroad 
  or 
  in 
  a 
  smoky 
  locality 
  

   may 
  have 
  their 
  characteristic 
  appearance 
  much 
  obscured 
  by 
  particles 
  of 
  

   soot 
  and 
  dirt, 
  and 
  those 
  living 
  on 
  trees 
  infested 
  to 
  a 
  considerable 
  extent 
  

   with 
  plant 
  lice 
  or 
  other 
  honeydew- 
  excreting 
  forms, 
  may 
  be 
  more 
  or 
  less 
  

   covered 
  with 
  a 
  sticky 
  layer 
  of 
  dirt. 
  These 
  variations 
  in 
  appearance 
  and 
  

   the 
  minuteness 
  of 
  scale 
  insects 
  render 
  their 
  correct 
  determination 
  very 
  

   difficult 
  for 
  one 
  who 
  has 
  not 
  given 
  the 
  group 
  special 
  study. 
  

  

  Key 
  based 
  on 
  superficial 
  characters 
  of 
  species 
  treated. 
  The 
  

  

  above 
  statement 
  regarding 
  the 
  variability 
  m 
  the 
  appearance 
  of 
  the 
  scales 
  of 
  

   these 
  insects 
  must 
  be 
  constantly 
  borne 
  in 
  mind, 
  and 
  identifications 
  made 
  

   in 
  this 
  manner, 
  unless 
  by 
  an 
  expert, 
  should 
  be 
  regarded 
  as 
  provisional. 
  

   An 
  effort 
  should 
  be 
  made 
  to 
  secure 
  both 
  young 
  and 
  full-grown 
  speci- 
  

   mens 
  and, 
  if 
  possible, 
  on 
  different 
  pieces 
  of 
  bark, 
  some 
  having 
  few 
  and 
  

   others 
  having 
  numerous 
  individuals, 
  as 
  this 
  will 
  give 
  a 
  better 
  idea 
  of 
  the 
  

   characteristics 
  of 
  the 
  insect. 
  A 
  good 
  magnifying 
  glass 
  or 
  lens 
  should 
  be 
  

   used 
  in 
  examining 
  the 
  scales. 
  A 
  very 
  serviceable 
  one 
  can 
  be 
  obtained 
  

   for 
  from 
  one 
  to 
  several 
  dollars, 
  and 
  it 
  is 
  invaluable 
  to 
  the 
  nurseryman 
  

   and 
  fruit-grower 
  in 
  enabling 
  him 
  to 
  examine 
  suspicious 
  appearances 
  

   more 
  closely. 
  The 
  characters 
  given 
  below 
  do 
  not 
  apply 
  to 
  any 
  of 
  the 
  

   oval, 
  usually 
  somewhat 
  hemispheric 
  brown 
  species 
  of 
  Lecanium, 
  but 
  

   only 
  to 
  the 
  species 
  of 
  armored 
  scale 
  insects 
  treated 
  of 
  in 
  detail. 
  

  

  The 
  species 
  briefly 
  characterized 
  below 
  are 
  arranged 
  in 
  the 
  order 
  of 
  

   their 
  present 
  abundance 
  in 
  New 
  York 
  state 
  ; 
  and, 
  if 
  the 
  description 
  in 
  the 
  

   first 
  paragraph 
  does 
  not 
  apply, 
  pass 
  to 
  the 
  second 
  and 
  so 
  continue. 
  It 
  

   may 
  frequently 
  happen 
  that 
  the 
  specimen 
  does 
  not 
  agree 
  with 
  the 
  descrip- 
  

   tions 
  given 
  in 
  any 
  of 
  the 
  paragraphs, 
  and 
  in 
  that 
  case 
  it 
  is 
  most 
  probably 
  

   one 
  of 
  the 
  species 
  not 
  treated, 
  of 
  which 
  there 
  are 
  many; 
  and 
  the 
  way 
  to 
  

   ascertain 
  the 
  identity 
  of 
  such 
  an 
  insect 
  is 
  to 
  send 
  specimens 
  to 
  an 
  ento- 
  

   mologist. 
  

  

  I 
  Adult 
  female 
  scales 
  elongated, 
  slender, 
  pear-shaped, 
  usuafly 
  slightly 
  

   curved, 
  almost 
  ^ 
  inch 
  long 
  and 
  brown. 
  Numerous 
  white 
  eggs 
  may 
  be 
  

  

  