﻿VII 
  

  

  forward 
  and 
  fastened 
  in 
  its 
  turn. 
  The 
  other 
  charac-teristic 
  motion 
  is 
  

   due 
  to 
  the 
  fact 
  that 
  the 
  larva 
  is 
  blind. 
  When 
  feeding, 
  after 
  the 
  

   posterior 
  end 
  has 
  been 
  attached 
  in 
  the 
  manner 
  described, 
  with 
  this 
  

   as 
  a 
  center 
  and 
  point 
  of 
  support, 
  the 
  anterior, 
  or 
  oral, 
  extremit}^ 
  

   moves 
  through 
  an 
  arc 
  of 
  about 
  120\ 
  touching 
  the 
  surface 
  on 
  which 
  

   the 
  larva 
  rests 
  several 
  times 
  while 
  so 
  moving. 
  If 
  during 
  this 
  move- 
  

   ment 
  it 
  should 
  happen 
  to 
  touch 
  anj' 
  living 
  thing 
  the 
  small 
  jaws 
  

   fasten 
  upon 
  it 
  and 
  the 
  fluids 
  of 
  its 
  bod 
  3' 
  are 
  extracted 
  by 
  the 
  sucking 
  

   process 
  described 
  above. 
  

  

  So 
  far 
  as 
  observed 
  SyrpJnis 
  ]arv;f' 
  are 
  not 
  choice 
  regarding 
  their 
  

   food, 
  attacking 
  with 
  absolute 
  impartiality 
  all 
  soft-bodied 
  insects 
  that 
  

   are 
  unfortunate 
  enough 
  to 
  fall 
  in 
  their 
  way, 
  including 
  even 
  their 
  

   own 
  kind. 
  Although 
  Sijrp}iu>^ 
  larvte 
  were 
  so 
  plentiful 
  in 
  the 
  cages 
  

   and 
  on 
  the 
  trees, 
  I 
  did 
  not 
  succeed 
  in 
  getting 
  them 
  to 
  pupate 
  in 
  the 
  

   former 
  and 
  observed 
  but 
  two 
  puparia 
  on 
  the 
  latter. 
  One 
  of 
  these 
  

   was 
  lost, 
  and 
  from 
  the 
  other 
  emerged 
  ten 
  specimens 
  of 
  the 
  parasite 
  

   Sijrphoctonus 
  pleuvdlis. 
  ParJiunciifon 
  soiiiaui-dtiis 
  Ashm. 
  emerged 
  

   from 
  a 
  jar 
  in 
  which 
  several 
  specimens 
  of 
  Sijrphiis 
  had 
  been 
  placed. 
  

  

  The 
  two 
  Chri/sopa 
  larv;e 
  may 
  be 
  known 
  by 
  their 
  long 
  curved 
  jaws, 
  

   spindle-shaped 
  body, 
  about 
  one-half 
  inch 
  long 
  when 
  grown, 
  free 
  from 
  

   the 
  woolly 
  excretion 
  of 
  the 
  Chrrmcs, 
  and 
  without 
  the 
  ijeculiar 
  move- 
  

   ments 
  of 
  the 
  Syrjihiis 
  larvjie. 
  I^sually 
  there 
  are 
  some 
  yellowish 
  mark- 
  

   ings 
  on 
  the 
  side 
  of 
  the 
  full 
  grown 
  larvae. 
  They 
  will 
  be 
  found 
  bur- 
  

   rowing 
  under 
  the 
  "wool.'' 
  

  

  The 
  larva 
  of 
  Hcuwrohiiis 
  dUernans 
  (PI. 
  II, 
  Fig. 
  7) 
  may 
  be 
  

   known 
  by 
  its 
  close 
  general 
  resemblance 
  to 
  that 
  of 
  Chrysopa, 
  differ- 
  

   ing, 
  however, 
  in 
  having 
  spines 
  on 
  the 
  back. 
  These 
  spines, 
  or 
  hairs, 
  

   becoming 
  entangled 
  in 
  the 
  woolly 
  excretion 
  of 
  the 
  Cheriiies 
  form 
  so 
  

   effectual 
  a 
  mask 
  that 
  the 
  larva 
  is 
  often 
  not 
  apparent 
  to 
  a 
  trained 
  eye 
  

   until 
  it 
  moves, 
  and 
  is 
  doubtless 
  concealed 
  when 
  at 
  rest, 
  from 
  eyes 
  

   more 
  directly 
  interested 
  in 
  its 
  discovery 
  than 
  are 
  those 
  of 
  man. 
  In 
  

   the 
  vigor 
  of 
  its 
  attack 
  on 
  the 
  Cher 
  Dies 
  it 
  is 
  second 
  to 
  neither 
  Cliri/- 
  

   sopa 
  nor 
  SijrpJuis. 
  

  

  An 
  indication 
  of 
  the 
  presence 
  of 
  the 
  SijrpJtii^i, 
  Chr/jsopa. 
  or 
  Hciii- 
  

   evohius 
  larvte 
  is 
  a 
  change 
  in 
  the 
  appearance 
  of 
  the 
  ''wool." 
  Early 
  in 
  

   the 
  spring 
  it 
  lies 
  close 
  to 
  the 
  bark, 
  and 
  is 
  compact 
  in 
  texture; 
  but 
  

   since 
  all 
  these 
  larvie 
  burrow 
  in 
  it 
  in 
  search 
  of 
  the 
  CItermcs. 
  soon 
  

   after 
  their 
  advent 
  it 
  becomes 
  loose 
  and 
  hangs 
  in 
  tangled 
  masses. 
  

  

  The 
  eggs 
  of 
  none 
  of 
  these 
  natural 
  enemies 
  were 
  obtained 
  except 
  

   those 
  of 
  Chrysopido'. 
  These 
  were 
  found 
  in 
  abundance 
  on 
  the 
  bark 
  

   of 
  the 
  trees 
  and 
  on 
  dead 
  leaves 
  adhering 
  to 
  the 
  bark. 
  They 
  may 
  be 
  

   easily 
  recognized, 
  each 
  egg 
  being 
  borne 
  on 
  a 
  stalk, 
  both 
  egg 
  and 
  

   stalk 
  being 
  white. 
  

  

  When 
  the 
  trees 
  were 
  first 
  examined 
  (March 
  '.>0) 
  , 
  scattered 
  thickly 
  

   through 
  the 
  "wool" 
  were 
  found 
  many 
  empty 
  puparia 
  about 
  one 
  tenth 
  

   inch 
  in 
  length 
  and 
  of 
  a 
  light 
  grayish 
  color. 
  Later 
  in 
  the 
  season 
  

   these 
  were 
  ascertained 
  to 
  belong 
  to 
  a 
  small 
  Hy. 
  Leucopis 
  simpler. 
  

   Loew. 
  These 
  flies 
  were 
  by 
  far 
  the 
  most 
  numerous 
  of 
  all 
  insects 
  

   observed 
  to 
  sustain 
  any 
  close 
  biological 
  relationship 
  to 
  the 
  Clwriiics. 
  

  

  