﻿4IO 
  NEW 
  YORK 
  STATE 
  MUSEUM 
  

  

  know 
  whether 
  this 
  abundance 
  of 
  hydras 
  always 
  occurs 
  when 
  the 
  trout 
  are 
  

   newly 
  hatched. 
  

  

  Two 
  fine 
  Diptera 
  belong 
  to 
  the 
  characteristic 
  fauna 
  of 
  Little 
  Clear 
  

   creek, 
  but 
  do 
  not 
  live 
  in 
  any 
  of 
  the 
  situations 
  we 
  have 
  been 
  discussing. 
  

   These 
  are 
  the 
  curious 
  phantom 
  fly, 
  Bittacomorpha 
  clavipes 
  

   Fabr., 
  and 
  our 
  largest 
  crane 
  fly, 
  Tipula 
  abdominalis 
  Say. 
  Both 
  

   live 
  almost 
  out 
  of 
  the 
  water 
  in 
  very 
  shallow 
  bays 
  filled 
  with 
  red-rotted 
  

   vegetation 
  and 
  both 
  are 
  very 
  common 
  in 
  such 
  places. 
  

  

  Gomphus 
  scudderi 
  Selys 
  was 
  common 
  in 
  the 
  creek 
  below 
  the 
  

   wagon 
  bridge, 
  but 
  was 
  not 
  taken 
  above 
  it. 
  

  

  Part 
  J 
  

   INSECT 
  LIFE 
  HISTORIES 
  

  

  In 
  the 
  following 
  pages 
  there 
  is 
  assumed 
  on 
  the 
  part 
  of 
  the 
  reader 
  such 
  

   a 
  knowledge 
  of 
  the 
  external 
  parts 
  of 
  insects 
  as 
  is 
  obtainable 
  from 
  the 
  

   elementary 
  textbook 
  of 
  entomology 
  or 
  of 
  .zoology. 
  He 
  should 
  know 
  

   that 
  the 
  body 
  of 
  an 
  insect 
  larva 
  is 
  composed 
  of 
  successive 
  rings 
  or 
  joints; 
  

   that 
  the 
  first 
  division 
  is 
  the 
  head 
  and 
  bears 
  the 
  eyes, 
  antennae 
  and 
  mouth 
  

   parts; 
  the 
  next 
  three 
  joints, 
  bearing 
  the 
  wing 
  and 
  leg 
  rudiments, 
  con- 
  

   stitute 
  the 
  thorax; 
  and 
  the 
  remaining 
  joints, 
  often 
  with 
  prop-legs 
  or 
  pro- 
  

   legs 
  under 
  them, 
  constitute 
  the 
  abdomen. 
  External 
  gills 
  are 
  arranged 
  in 
  

   delicate 
  whitish 
  tufts 
  when 
  in 
  a 
  sheltered 
  position, 
  or, 
  when 
  exposed, 
  are 
  

   thin 
  plates 
  traversed 
  by 
  delicate 
  air 
  tubes. 
  In 
  addition 
  to 
  these, 
  there 
  

   are 
  at 
  the 
  sides 
  of 
  the 
  abdomen, 
  longer, 
  paired, 
  simple, 
  pointed 
  appen- 
  

   dages, 
  called 
  lateral 
  filaments, 
  which 
  also, 
  when 
  small 
  and 
  delicate, 
  may 
  

   serve 
  the 
  respiratory 
  function. 
  Lateral 
  filaments, 
  gills 
  (with 
  very 
  few 
  

   exceptions) 
  and 
  prolegs 
  disappear 
  with 
  the 
  end 
  of 
  larval 
  life, 
  and 
  are 
  

   absent 
  in 
  the 
  adult 
  insect. 
  

  

  In 
  the 
  immature 
  stages 
  insects 
  differ 
  wonderfully 
  ; 
  but 
  there 
  are 
  two 
  

   types 
  of 
  larvae, 
  which 
  have 
  been 
  distinguished 
  by 
  the 
  degree 
  of 
  differ- 
  

   ence 
  between 
  larva 
  and 
  adult 
  insect: 
  i) 
  those 
  called 
  nymphs, 
  which 
  

   differ 
  but 
  little 
  from 
  the 
  adults 
  in 
  general 
  organization, 
  and 
  when 
  grown 
  

   transform 
  directly 
  to 
  imagos, 
  without 
  having 
  entered 
  on 
  a 
  quiescent 
  

   pupal 
  stage 
  ; 
  and 
  2) 
  larvae 
  proper, 
  which 
  differ 
  very 
  greatly 
  from 
  their 
  

   imagos, 
  having 
  the 
  adult 
  appendages 
  reduced 
  in 
  size 
  or 
  altogether 
  

   wanting, 
  wings 
  never 
  visible 
  externally, 
  and 
  requiring 
  a 
  quiescent 
  pupal 
  

   stage, 
  when 
  they 
  have 
  done 
  feeding, 
  before 
  transforming 
  to 
  the 
  imago. 
  

   These 
  two 
  groups 
  constitute 
  the 
  primary 
  divisions 
  of 
  the 
  table 
  given 
  

   below. 
  ^The 
  student 
  will 
  find 
  in 
  Comstock's 
  Manual 
  for 
  the 
  study 
  of 
  

   insects^ 
  or 
  in 
  his 
  Insect 
  Ufe^ 
  or 
  in 
  a 
  number 
  of 
  other 
  books 
  that 
  are 
  not 
  so 
  

  

  