﻿[24] 
  REPORT 
  UNITED 
  STATES 
  ENTOMOLOGICAL 
  COMMISSION. 
  

  

  end 
  of 
  the 
  respective 
  knot. 
  The 
  hatched 
  fly 
  in 
  such 
  a 
  case 
  may 
  be 
  

   pnzzledj 
  when 
  the 
  upper 
  space 
  of 
  the 
  stubble 
  is 
  shut 
  off 
  by 
  the 
  next 
  

   knot, 
  and 
  no 
  other 
  outlet 
  exists 
  for 
  its 
  escape. 
  

  

  The 
  pupa 
  shells 
  sticking 
  to 
  the 
  stalks 
  usually 
  differ 
  in 
  form 
  and 
  

   sculpture 
  from 
  those 
  occurring 
  on 
  young 
  sprouts 
  in 
  the 
  neighborhood 
  

   of 
  the 
  root. 
  Those 
  show 
  a 
  flattening 
  below 
  and 
  above 
  ; 
  on 
  the 
  suTface 
  

   occur 
  faint 
  wrinkles 
  and 
  tender 
  longitudinal 
  lines. 
  These 
  and 
  similar 
  

   deviations 
  from 
  the 
  typical 
  cylinder-form 
  originate 
  by 
  sinking 
  together 
  

   and 
  drying 
  up 
  of 
  the 
  origioally 
  entirely 
  membranous 
  shell. 
  

  

  Peculiar 
  malformations, 
  such 
  as 
  are 
  usually 
  produced 
  by 
  the 
  attacks 
  

   of 
  gall-gnat 
  maggots 
  on 
  vascular 
  plants, 
  I 
  did 
  not 
  observe, 
  at 
  least 
  

   on 
  wheat 
  and 
  rye, 
  but 
  on 
  barley 
  aftergrowth 
  the 
  spot 
  where 
  the 
  mag- 
  

   got 
  of 
  our 
  fly 
  rested, 
  occasionally 
  exhibited 
  a 
  knotty 
  swelling. 
  

  

  § 
  5. 
  The 
  new 
  cereal 
  gall-gnat 
  as 
  compared 
  with 
  Oecidomyia 
  

  

  secalina 
  loew. 
  

  

  The 
  ex.aminations 
  of 
  our 
  gall-gnat 
  hitherto 
  conducted 
  compel 
  us 
  to 
  

   a 
  comparison 
  w^ith 
  the 
  rye 
  gall 
  gnat 
  (Cecidomyia 
  secalina) 
  described 
  

   by 
  Dr. 
  Loew, 
  as 
  for 
  the 
  former 
  we 
  have 
  not 
  yet 
  found 
  a 
  new 
  scientific 
  

   name. 
  Loew, 
  in 
  the 
  preface 
  of 
  his 
  x^aper 
  ''Die 
  neue 
  Kornmade" 
  [The 
  

   new 
  Corn-maggot], 
  states 
  it 
  as 
  his 
  principal 
  purpose, 
  to 
  give 
  his 
  observa- 
  

   tions 
  on 
  the 
  rye 
  gall-gnat 
  such 
  a 
  direction 
  that 
  the 
  hitherto 
  frequent 
  

   confounding 
  of 
  the 
  maggot 
  with 
  other 
  larvae 
  shall 
  be 
  avoided, 
  and 
  

   that, 
  on 
  the 
  other 
  hand, 
  a 
  full 
  knowledge 
  M 
  the 
  developmental 
  his- 
  

   tory 
  and 
  biology 
  of 
  the 
  insect 
  shall 
  be 
  obtained, 
  as 
  necessary 
  to 
  ener- 
  

   getically 
  fight 
  against 
  this 
  enemy 
  of 
  the 
  (?rops. 
  It 
  is 
  evident 
  that 
  the 
  

   13aper 
  does 
  not 
  pretend 
  to 
  be 
  a 
  complete 
  monograph 
  of 
  the 
  rye 
  gall- 
  

   gnat. 
  The 
  want 
  of 
  illustrations 
  of 
  his 
  described 
  insect 
  shows 
  this 
  

   likewise. 
  The 
  few 
  observations 
  known 
  about 
  the 
  fly 
  at 
  the 
  time 
  of 
  

   writing 
  the 
  paper 
  the 
  author 
  utilized 
  for 
  his 
  description, 
  throughout 
  

   showing 
  a 
  good 
  authority 
  on 
  gall-gnats. 
  

  

  What 
  Loew 
  states 
  on 
  the 
  biology 
  and 
  the 
  characters 
  of 
  his 
  rye-gnat 
  

   agrees 
  even 
  in 
  the 
  most 
  minute 
  details 
  with 
  my 
  experiences 
  on 
  the 
  

   above 
  described 
  gall-gnat, 
  so 
  that 
  it 
  is 
  not 
  necessary 
  for 
  me 
  to 
  give 
  proof 
  

   of 
  the 
  unity 
  of 
  his 
  with 
  our 
  species. 
  I 
  arrived 
  at 
  a 
  diverse 
  result 
  

   only 
  in 
  regard 
  to 
  a 
  few 
  rather 
  irrelevant 
  points. 
  Thus, 
  for 
  instance, 
  

   Loew 
  calls 
  the 
  color 
  whitish 
  in 
  middle 
  of 
  October 
  ; 
  at 
  that 
  time 
  I 
  only 
  

   found 
  the 
  external 
  surface 
  to 
  be 
  so, 
  the 
  inner 
  reddish-yellow. 
  Other 
  

   differences 
  relate 
  almost 
  exclusively 
  to 
  the 
  coloration 
  of 
  some 
  parts 
  of 
  

   the 
  body 
  of 
  the 
  female 
  (the 
  male 
  was 
  unknown 
  to 
  Loew). 
  Kot 
  too 
  much 
  

   stress 
  should, 
  I 
  think, 
  be 
  put 
  on 
  those 
  latter 
  differences, 
  as 
  the 
  judg- 
  

   ment 
  of 
  color 
  depends 
  nowadays 
  uiDon 
  subjective 
  conceptions 
  and 
  on 
  

   diverse 
  causes. 
  

  

  I 
  have 
  yet 
  to 
  add 
  that 
  the 
  pupae 
  of 
  his 
  Cecidomyia 
  secalina 
  sent 
  to 
  me 
  

   by 
  Loew 
  perfectly 
  agree 
  with 
  those 
  of 
  our 
  gall- 
  gnat, 
  which 
  is 
  again 
  an- 
  

   other 
  proof 
  of 
  the 
  identity 
  of 
  his 
  species 
  with^urs. 
  

  

  § 
  6. 
  Comparison 
  of 
  Cecidomyia 
  secalina 
  Loew 
  with 
  Cecido- 
  

   myia 
  DESTRUCTOR 
  SAY. 
  

  

  Li 
  most 
  standard 
  zoological 
  books 
  we 
  find 
  a 
  gall-gnat 
  mentioned, 
  usually 
  

   under 
  the 
  name 
  of 
  Hessian 
  fly 
  [Cecidomyia 
  destructor 
  Say), 
  which 
  for 
  a 
  

   long 
  time 
  has 
  caused 
  great 
  devastations 
  in 
  wheat 
  in 
  JS^orth 
  America. 
  

   The 
  devastations 
  were 
  in 
  some 
  districts 
  of 
  the 
  United 
  States 
  at 
  times 
  

   so 
  great 
  that 
  the 
  thought 
  of 
  giving 
  up 
  wheat 
  culture 
  was 
  entertained.* 
  

  

  *As 
  -was 
  the 
  case 
  in 
  Ohio, 
  1857; 
  John 
  Klippart, 
  Jahresheiicht 
  iiber 
  die 
  Verhandlungen 
  der 
  Acker- 
  

   baugesellschaften 
  in 
  Ohio, 
  1858, 
  "Aushmd," 
  Is^o. 
  14, 
  1860. 
  

  

  