﻿IX 
  

   KEYS 
  TO 
  LARVAL 
  AND 
  PUPAL 
  FORMS 
  OF 
  NATURAL 
  ENEMIES. 
  

  

  As 
  a 
  key 
  that 
  will 
  enable 
  any 
  one 
  interested 
  to 
  distinguish 
  the 
  

   principal 
  iiinect 
  enemies 
  of 
  Chermes 
  may 
  be 
  of 
  value, 
  one 
  is 
  here 
  in- 
  

   serted. 
  It 
  is 
  founded 
  on 
  larval 
  peculiarities, 
  since 
  it 
  is 
  in 
  this 
  stage 
  

   that 
  they 
  are 
  apt 
  to 
  be 
  observed. 
  

  

  a. 
  — 
  Larva 
  very 
  small, 
  bright 
  red. 
  footless. 
  — 
  Leucopis 
  simplex. 
  

   Larva 
  larger, 
  not 
  red. 
  — 
  b. 
  

  

  b. 
  — 
  Larva 
  widening 
  toward 
  the 
  posterior 
  extremity, 
  footless, 
  usually 
  

   covered 
  with 
  woolly 
  excretion 
  of 
  Chermes, 
  jaws 
  very 
  small.— 
  

   Syrpluis. 
  

  

  Larva 
  short, 
  thick, 
  several 
  rows 
  of 
  spines, 
  body 
  of 
  nearly 
  the 
  

   same 
  diameter 
  throughout, 
  possessing 
  feet. 
  — 
  Ladybirds. 
  

  

  Larva 
  slender, 
  tapering 
  at 
  each 
  end, 
  jaws 
  large, 
  curved. 
  — 
  c. 
  

  

  c. 
  — 
  Larva 
  spiny, 
  with 
  "wool" 
  on 
  the 
  hd^ck.- 
  Hemerohius. 
  

   Larva 
  not 
  spiny, 
  usually 
  clear 
  of 
  "wool." 
  — 
  Chrysopa. 
  

  

  To 
  this 
  key 
  is 
  added 
  another 
  by 
  means 
  of 
  which 
  the 
  pupal 
  stages 
  

   of 
  the 
  same 
  insects 
  may 
  be 
  distinguished. 
  

  

  a. 
  — 
  Pupa 
  inclosed 
  in 
  a 
  silk 
  cocoon, 
  spherical, 
  opening 
  ])y 
  a 
  circu- 
  

   lar 
  lid. 
  — 
  b. 
  

   Pupa 
  not 
  inclosed 
  in 
  a 
  cocoon, 
  not 
  spherical, 
  

   b. 
  — 
  Cocoon 
  of 
  white 
  silk. 
  — 
  Chrysopja. 
  

  

  Cocoon 
  of 
  brown 
  silk. 
  — 
  Hemerobiiis. 
  

   c. 
  — 
  Attached 
  by 
  the 
  side. 
  

  

  Attached 
  by 
  one 
  end, 
  often 
  possessing 
  the 
  power 
  of 
  motion. 
  — 
  

   Ladybirds. 
  

   d. 
  — 
  Small, 
  \s 
  in. 
  or 
  less, 
  reddish 
  or 
  grayish 
  color, 
  opening 
  at 
  end. 
  — 
  

   Leucoijis. 
  

   Larger, 
  ^5 
  to 
  \ 
  in., 
  brownish. 
  — 
  Syrpltiis. 
  

  

  COMPARATIVE 
  LIFE 
  HISTORY 
  OF 
  THE 
  CHERMES 
  AND 
  ITS 
  ENEMIES. 
  

  

  The 
  important 
  events 
  noted 
  in 
  the 
  life 
  of 
  the 
  Chermes, 
  up 
  to 
  June 
  

   10, 
  when 
  my 
  observations 
  ceased, 
  are 
  given 
  in 
  the 
  accompanying 
  

   tables 
  (pp. 
  X, 
  xi). 
  

  

  Attention 
  is 
  called 
  to 
  the 
  following 
  facts 
  exhibited 
  b}- 
  this 
  cal- 
  

   endar: 
  

  

  1. 
  There 
  is 
  a 
  period 
  of 
  a 
  few 
  days 
  in 
  early 
  spring 
  when 
  the 
  

   Chermes 
  is 
  comparatively 
  free 
  from 
  attack, 
  though 
  its 
  enemies 
  are 
  no 
  

   doubt 
  present. 
  The 
  larva' 
  of 
  Leucopis 
  were 
  on 
  the 
  pines 
  in 
  small 
  

   numbers, 
  and 
  the 
  adults 
  of 
  Chrysopa, 
  Hemcrobius. 
  and 
  the 
  ladybirds 
  

   were 
  observed 
  in 
  numbers 
  in 
  other 
  locations 
  at 
  this 
  time. 
  

  

  2. 
  The 
  severity 
  of 
  the 
  attack 
  reaches 
  its 
  climax 
  at 
  the 
  period 
  

   when 
  the 
  larva" 
  of 
  the 
  Chermes 
  are 
  attaching 
  themselves 
  (Apr. 
  26). 
  

   At 
  that 
  time 
  the 
  Chrysopa 
  and 
  SyrpJius 
  larvfB 
  are 
  destroying 
  great 
  

   numbers- 
  Moreover, 
  although 
  not 
  observed 
  at 
  the 
  time, 
  an 
  inspec- 
  

  

  