﻿AQUATIC 
  INSECTS 
  IN 
  THE 
  ADIRONDACKS 
  4II 
  

  

  good 
  as 
  these, 
  serviceable 
  tables 
  for 
  the 
  determination 
  of 
  the 
  adult 
  

   insects. 
  We 
  give 
  here 
  a 
  table 
  that 
  will 
  serve 
  for 
  distinguishing 
  the 
  orders 
  

   in 
  the 
  larval 
  stage. 
  So 
  few 
  relatively 
  of 
  the 
  larvae 
  of 
  aquatic 
  insects 
  are 
  

   known 
  as 
  yet, 
  that 
  this 
  table 
  must 
  be 
  considered 
  tentative 
  as 
  to 
  its 
  state- 
  

   ments 
  of 
  group 
  characters. 
  

  

  In 
  all 
  the 
  following 
  tables 
  and 
  descriptions 
  the 
  characters 
  described 
  

   and 
  the 
  measurements 
  given 
  apply 
  to 
  fully 
  grown 
  nymphs 
  or 
  larvae 
  

   except 
  when 
  otherwise 
  expressly 
  stated. 
  

  

  KEY 
  TO 
  ORDERS 
  OF 
  AQUATIC 
  INSECT 
  LARVAE* 
  

   a 
  Larvae 
  with 
  wings 
  developing 
  externally 
  (called 
  nymjjhs 
  in 
  this 
  i)aper) 
  and 
  

   no 
  quiescent 
  pupal 
  stage 
  

   b 
  With 
  biting 
  mouth 
  parts 
  

   e 
  With 
  long, 
  filamentous 
  caudal 
  setae; 
  labium 
  not 
  longer 
  than 
  the 
  head, 
  

   and 
  not 
  folded 
  on 
  itself 
  like 
  a 
  hinge 
  

   d 
  Gills 
  mainly 
  under 
  the 
  thorax 
  j 
  tarsal 
  claws 
  two 
  ; 
  caudal 
  setae 
  generally 
  

  

  two 
  .(stone 
  flies) 
  Plecoptera 
  

  

  dd 
  Gills 
  mainly 
  on 
  the 
  sides 
  of 
  the 
  abdomen 
  ; 
  tarsal 
  claws 
  single; 
  caudal 
  

  

  setae 
  generally 
  three 
  (May 
  flies) 
  Ephemerid 
  a 
  

  

  CO 
  Caudal 
  setae 
  represented 
  by 
  three 
  broad, 
  leaflike 
  respiratory 
  plates 
  

   traversed 
  by 
  tr;icheae, 
  or 
  by 
  small 
  spinous 
  appendages; 
  labium 
  much 
  

   longer 
  than 
  the 
  head 
  when 
  extended 
  ; 
  at 
  rest, 
  folded 
  on 
  itself 
  like 
  a 
  

   hinge 
  and 
  extending 
  between 
  the 
  bases 
  of 
  the 
  fore 
  legs 
  

  

  (dragon 
  flies 
  and 
  damsel 
  flies) 
  O 
  don 
  at 
  a 
  

   bl) 
  Mouth 
  parts 
  combined 
  into 
  a 
  jointed 
  beak, 
  which 
  is 
  directed 
  beneath 
  the 
  

  

  head 
  backward 
  between 
  the 
  fore 
  legs 
  Hemiptera 
  

  

  aa 
  Lm-vae 
  proper, 
  with 
  wings 
  developing 
  internally, 
  and 
  invisible 
  till 
  the 
  as- 
  

   sumption 
  of 
  a 
  quiescent 
  pupal 
  stage 
  

   h 
  With 
  jointed 
  thoracic 
  legs 
  

   With 
  slender, 
  decurved, 
  piercing 
  mouth 
  parts, 
  half 
  as 
  long 
  as 
  the 
  body; 
  

   small 
  larvae, 
  living 
  on 
  fresh-water 
  sponges. 
  Family 
  Hemerobiidae 
  of 
  

   Neuroptera 
  

   CO 
  With 
  biting 
  mouth 
  parts 
  

   d 
  With 
  a 
  pair 
  of 
  prolegs 
  on 
  the 
  last 
  segment 
  only 
  (except 
  in 
  Si 
  alls, 
  

   plate 
  29, 
  which 
  has 
  a 
  single 
  long 
  median 
  tail-like 
  process 
  at 
  the 
  

   end 
  of 
  the 
  abdomen) 
  these 
  directed 
  backward, 
  and 
  armed 
  each 
  with 
  

   one 
  or 
  two 
  strong 
  hooks 
  or 
  claws 
  

   e 
  Abdominal 
  segments 
  each 
  with 
  a 
  pair 
  of 
  long, 
  lateral 
  filaments 
  

  

  Family 
  Sialidae 
  of 
  Neuroptera 
  

  

  ee 
  Abdominal 
  segments 
  without 
  long, 
  muscular, 
  lateral 
  filaments, 
  often 
  

  

  with 
  minute 
  gill 
  filaments 
  ; 
  cylindric 
  larvae, 
  generally 
  living 
  in 
  

  

  portable 
  cases 
  (caddis 
  flies) 
  Trichoptera 
  

  

  1 
  The 
  Thysanura, 
  or 
  springtails, 
  common 
  on 
  the 
  surface 
  of 
  water, 
  but 
  not 
  living 
  in 
  it 
  are 
  not 
  In. 
  

   eluded 
  in 
  this 
  table. 
  They 
  will 
  be 
  readily 
  recognizable, 
  If 
  collected, 
  by 
  their 
  very 
  minute 
  size, 
  

   entire 
  absence 
  of 
  wings, 
  mouth 
  parts 
  retracted 
  within 
  the 
  head, 
  and 
  the 
  forked 
  spring 
  beneath 
  the 
  

   abdomeo. 
  

  

  