﻿AQUATIC 
  INSECTS 
  IN 
  THE 
  ADIRONDACKS 
  565 
  

  

  prothorax. 
  Another 
  black 
  line 
  incircles 
  the 
  head 
  and 
  prothorax, 
  running 
  

   through 
  the 
  base 
  of 
  the 
  Y, 
  passing 
  obliquely 
  downward 
  to 
  the 
  gula 
  

   which 
  is 
  of 
  the 
  same 
  color. 
  The 
  mesothoracic 
  shield 
  is 
  spotted 
  with 
  

   black 
  and 
  brown. 
  The 
  legs 
  are 
  hght 
  brown, 
  the 
  coxa, 
  trochanter, 
  

   and 
  proximal 
  part 
  of 
  the 
  femur 
  being 
  margined 
  with 
  black. 
  The 
  

   first 
  and 
  second 
  pairs 
  of 
  legs 
  each 
  have 
  one 
  prominent 
  spur 
  on 
  

   the 
  tibia. 
  The 
  third 
  pair 
  of 
  legs 
  is 
  more 
  slender 
  and 
  hairy 
  than 
  

   the 
  others, 
  and 
  the 
  tarsi 
  are 
  terminated 
  by 
  small, 
  feathery 
  brushes 
  

   instead 
  of 
  hooks. 
  Two 
  rows 
  of 
  respiratory 
  filaments 
  occur 
  on 
  the 
  dorsal, 
  

   and 
  two 
  on 
  the 
  ventral 
  side. 
  The 
  number 
  of 
  filaments 
  issuing 
  at 
  the 
  same 
  

   spot 
  on 
  the 
  dorsal 
  side 
  is 
  o, 
  4, 
  4, 
  4, 
  3, 
  2, 
  2, 
  o, 
  o, 
  and 
  on 
  the 
  ventral 
  side 
  

   Oj 
  3j 
  3) 
  3) 
  2, 
  2, 
  o, 
  o, 
  o, 
  the 
  figures 
  representing 
  the 
  segments 
  in 
  order. 
  

   These 
  filaments 
  are 
  placed 
  at 
  the 
  anterior 
  margins 
  of 
  the 
  segments. 
  The 
  

   hooks 
  terminating 
  the 
  body 
  are 
  supported 
  on 
  two-jointed 
  prolegs. 
  

  

  Pupa. 
  (PI. 
  13, 
  fig. 
  3) 
  Length 
  12 
  mm. 
  Width 
  2 
  mm. 
  Antennae 
  

   10 
  mm. 
  Wings 
  7 
  mm. 
  Head 
  and 
  thorax 
  white; 
  abdomen 
  pink 
  or 
  

   green. 
  Two 
  black 
  lines 
  run 
  the 
  length 
  of 
  the 
  body 
  both 
  above 
  and 
  

   beneath. 
  Respiratory 
  filaments 
  persist 
  on 
  both 
  dorsal 
  and 
  ventral 
  sides. 
  

   The 
  lateral 
  fringe 
  which 
  forms 
  a 
  loop 
  under 
  the 
  eighth 
  segment 
  is 
  com- 
  

   posed 
  of 
  soft 
  black 
  hairs. 
  The 
  spurs 
  on 
  the 
  tibiae, 
  which 
  appear 
  as 
  

   feathery 
  brushes, 
  number 
  2, 
  4, 
  4 
  on 
  the 
  first, 
  second 
  and 
  third 
  pairs 
  

   of 
  legs 
  respectively. 
  Hooks 
  pointing 
  backward 
  occur 
  in 
  two 
  rows 
  on 
  the 
  

   dorsal 
  side 
  of 
  the 
  third, 
  fourth, 
  fifth 
  and 
  sixth 
  segments 
  at 
  the 
  anterior 
  

   edge 
  of 
  the 
  segments. 
  Two 
  plates 
  with 
  spikes 
  pointing 
  forward 
  are 
  at 
  

   the 
  posterior 
  edge 
  of 
  the 
  fifth 
  segment. 
  

  

  Poly 
  centr 
  opus 
  lucidus 
  Hag. 
  ? 
  

  

  Plate 
  13, 
  figures 
  7-11 
  

  

  Habitat. 
  Larvae 
  and 
  pupae 
  were 
  found 
  in 
  sandy 
  bottoms 
  with 
  Httle 
  

   or 
  no 
  vegetation. 
  Adults 
  were 
  commonly 
  found 
  resting 
  on 
  vegetation 
  

   in 
  the 
  creek 
  and 
  on 
  the 
  side 
  of 
  the 
  hatchery 
  near 
  the 
  stream. 
  

  

  Occurrence. 
  Abundant 
  throughout 
  the 
  period 
  of 
  work. 
  

  

  Case. 
  (PI. 
  13, 
  fig. 
  10) 
  Very 
  soft 
  tubular 
  case 
  of 
  fine 
  sand. 
  It 
  is 
  

   frequently 
  branched 
  and 
  where 
  the 
  insect 
  lies 
  has 
  two 
  distinct 
  layers. 
  

   The 
  tube 
  is 
  much 
  longer 
  than 
  the 
  larva 
  and 
  is 
  not 
  portable. 
  The 
  

   position 
  of 
  the 
  larva 
  or 
  pupa 
  is 
  readily 
  recognized. 
  They 
  lie 
  in 
  a 
  part 
  of 
  

   the 
  case 
  twice 
  the 
  diameter 
  of 
  the 
  rest 
  of 
  the 
  tube. 
  

  

  Larva. 
  (PI. 
  13, 
  fig. 
  7) 
  Length 
  14 
  mm. 
  Width 
  2 
  mm. 
  Head 
  

   yellow 
  ; 
  prothorax 
  yellow 
  with 
  black 
  line 
  incircling 
  its 
  rear 
  margin. 
  The 
  

  

  