﻿WAGNER 
  ON 
  THE 
  HESSIAN 
  FLY. 
  [27j 
  

  

  soon 
  afterwards 
  it 
  strikes 
  us: 
  "The 
  two 
  basal 
  joints 
  of 
  each 
  antenna 
  

   are 
  globular." 
  The 
  demonstration 
  in 
  these 
  two 
  points 
  is 
  evidently 
  ina(> 
  

   curate, 
  allowing 
  however 
  scarcely 
  a 
  doubt 
  as 
  to 
  the 
  true 
  meaniug 
  of 
  

   the 
  author. 
  If 
  Fitch, 
  in 
  the 
  first 
  sentence, 
  had 
  included 
  among 
  the 
  10 
  

   joints 
  of 
  cylindric-oval 
  form, 
  the 
  basal 
  joints, 
  he 
  would 
  not 
  have 
  called 
  

   them 
  globular, 
  else 
  we 
  should 
  substitute 
  an 
  absurdity, 
  which 
  would 
  not 
  

   be 
  justifiable 
  in 
  the 
  case 
  of 
  so 
  excellent 
  an 
  entomologist. 
  But 
  if 
  we 
  un- 
  

   derstand 
  by 
  the 
  10 
  joints 
  only 
  the 
  flagellar 
  joints, 
  every 
  scruple 
  passes. 
  

   I 
  must 
  besides 
  recall 
  that 
  the 
  number 
  of 
  flagellar 
  joints 
  in 
  the 
  females 
  

   varies 
  between 
  14 
  or 
  10 
  ; 
  therefore 
  had 
  Fitch 
  really- 
  only 
  decided 
  upon 
  

   14 
  flagellar 
  joints, 
  even 
  this 
  could 
  not 
  yet 
  really 
  make 
  a 
  specific 
  differ- 
  

   ence. 
  

   Loew 
  says 
  further 
  on, 
  in 
  relation 
  to 
  difterences 
  : 
  

  

  According 
  to 
  his 
  description 
  the 
  joints 
  of 
  the 
  antonn<» 
  of 
  the 
  female 
  are 
  connected 
  

   by 
  thin 
  pedicels, 
  which 
  are 
  one-third 
  of 
  the 
  length 
  of 
  the 
  joints, 
  the 
  last 
  joint 
  being- 
  

   at 
  least 
  one-third 
  longer 
  than 
  the 
  i>ennltiniato 
  joint 
  ; 
  in 
  the 
  female 
  rye 
  gall-gnat 
  

   the 
  pedicels 
  connecting 
  the 
  separate 
  anteinial 
  joints 
  are 
  so 
  short 
  that 
  the 
  joints 
  a])- 
  

   pear 
  to 
  ait 
  immediately 
  one 
  upon 
  the 
  other, 
  and 
  the 
  last 
  joint 
  is 
  scarcely 
  longer 
  

   than 
  the 
  penultimate. 
  

  

  A 
  difference 
  is 
  here 
  maintained 
  due 
  to 
  a 
  mistake 
  in 
  translating. 
  It 
  

   says 
  in 
  the 
  description 
  (Fitches) 
  : 
  "The 
  joints 
  are 
  separated 
  from 
  each 
  

   other 
  by 
  very 
  short 
  transluceut 
  filaments, 
  having 
  a 
  diameter 
  about 
  a 
  

   third 
  as 
  great 
  as 
  the 
  joints 
  themselves. 
  The 
  word 
  "diameter" 
  was 
  

   wrongly 
  translated 
  by 
  Dr. 
  Loew 
  as 
  " 
  length," 
  I 
  found 
  the 
  last 
  in 
  all 
  

   my 
  examined 
  specimens 
  also 
  longer 
  than 
  the 
  penultimate; 
  but 
  I 
  take 
  

   Fitch's 
  statement 
  relating 
  to 
  the 
  proijortion 
  of 
  length 
  of 
  the 
  last 
  two 
  

   joints 
  in 
  the 
  given 
  successive 
  meaniug 
  as 
  an 
  exaggeration, 
  

  

  I 
  believe 
  now 
  that 
  I 
  have 
  sufficiently 
  demonstrated 
  the 
  unten 
  ability 
  

   of 
  the 
  differences 
  put 
  forth 
  by 
  Loew 
  between 
  his 
  rye 
  gall-gnat 
  and 
  the 
  

   Hessian 
  fly. 
  That 
  in 
  reality 
  our 
  cereal 
  gall-gnat 
  is 
  identical 
  with 
  the 
  Hes- 
  

   sian 
  fly 
  everybody 
  can 
  convince 
  himself 
  who 
  is 
  not 
  afraid 
  to 
  make 
  the 
  

   study 
  of 
  natural 
  history 
  of 
  the 
  insect 
  for 
  a 
  long 
  time 
  a 
  special 
  matter 
  of 
  

   inquiry, 
  and 
  who 
  will 
  compare 
  the 
  results 
  obtained 
  by 
  thorough 
  and 
  ex- 
  

   tensive 
  observations 
  and 
  examinations, 
  which, 
  as 
  I 
  sincerely 
  expect, 
  will 
  

   deviate 
  only 
  in 
  irrelevant 
  points 
  from 
  those 
  stated 
  in 
  this 
  brief 
  disserta- 
  

   tion 
  regarding 
  the 
  manner 
  of 
  life 
  and 
  the 
  characters 
  of 
  the 
  American 
  

   species 
  in 
  its 
  various 
  stages 
  of 
  growth. 
  

  

  In 
  concluding 
  this 
  paragraph 
  I 
  will 
  not 
  neglect 
  to 
  dwell 
  upon 
  the 
  very 
  

   closely 
  related 
  question 
  whether 
  the 
  Hessian 
  fly 
  has 
  been 
  already 
  earlier 
  

   observed 
  in 
  Europe. 
  

  

  Herrick 
  i)ublished 
  in 
  Silliman's 
  Journal 
  (vol. 
  XII, 
  p. 
  154), 
  that 
  Dana, 
  

   " 
  who, 
  in 
  company 
  with 
  him, 
  made 
  a 
  thorough 
  examination 
  of 
  the 
  pecu- 
  

   liarities 
  of 
  the 
  Hessian 
  fly," 
  collected 
  in 
  1834, 
  in 
  a 
  field 
  of 
  wheat, 
  on 
  the 
  

   island 
  of 
  Minorca, 
  larvae 
  and 
  pupse, 
  from 
  which 
  latter 
  insects 
  issued, 
  

   which 
  he, 
  assisted 
  by 
  a 
  drawing 
  of 
  the 
  Hessian 
  fly, 
  declared 
  to 
  be 
  Ce- 
  

   cidomyia 
  destructor. 
  In 
  the 
  same 
  year 
  Dana 
  found 
  the 
  same 
  insect 
  also 
  

   at 
  Mahon, 
  near 
  Toulon 
  and 
  Najdes. 
  Dana 
  forwarded 
  specimens 
  of 
  the 
  

   imago 
  and 
  pupae 
  from 
  ^lahon 
  to 
  Herrick 
  in 
  America, 
  about 
  which 
  the 
  

   latter 
  says 
  : 
  "They 
  arrived 
  in 
  safety, 
  and 
  after 
  a 
  careful 
  examination 
  I 
  

   saw 
  no 
  good 
  reason 
  to 
  doubt 
  the 
  identity 
  of 
  this 
  insect 
  with 
  the 
  Hes- 
  

   sian 
  fly." 
  It 
  seems 
  to 
  us 
  that 
  Herrick's 
  (not 
  Fitch's) 
  judgment 
  on 
  the 
  

   insect 
  received 
  from 
  Europe 
  is 
  not 
  expressed 
  in 
  so 
  "extremely 
  uncer- 
  

   tain" 
  a 
  way 
  as 
  Loew 
  thinks. 
  Acquainted 
  with 
  the 
  always 
  inevitable, 
  

   often 
  indistinguishable 
  modifications 
  of 
  the 
  insect 
  post 
  mortem^ 
  and 
  the 
  

   often 
  considerable 
  differences 
  of 
  the 
  pupa-shell 
  of 
  the 
  typical 
  form, 
  a 
  

   more 
  determined 
  formulation 
  of 
  judgment 
  could 
  scarcely 
  appear 
  admis- 
  

  

  