﻿[10] 
  REPORT 
  UNITED 
  STATES 
  ENTOMOLOGICAL 
  COMMISSION. 
  

  

  Although 
  this 
  table 
  comprises 
  but 
  a 
  small 
  number 
  of 
  individuals, 
  it 
  

   nevertheless 
  elucidates 
  several 
  imj)ortant 
  points, 
  as 
  it 
  just 
  answers 
  some 
  

   questions 
  which 
  are 
  of 
  importance 
  in 
  the 
  characterization 
  of 
  the 
  imago. 
  

   Of 
  the 
  twelve 
  males 
  hatched, 
  nine 
  specimens 
  have 
  antennae 
  with 
  16 
  

   joints, 
  in 
  two 
  of 
  them 
  the 
  number 
  of 
  joints 
  is 
  15 
  and 
  only 
  in 
  one 
  17. 
  

   Most 
  females 
  have 
  15, 
  three 
  have 
  14, 
  and 
  two 
  have 
  16 
  joints. 
  Hence 
  the 
  

   normal 
  number 
  of 
  joints 
  for 
  both 
  sexes 
  is 
  not 
  alike, 
  but 
  16 
  for 
  the 
  male 
  

   and 
  15 
  for 
  the 
  female. 
  

  

  The 
  determination 
  of 
  the 
  numerical 
  proportion 
  of 
  both 
  sexes 
  for 
  the 
  

   time 
  cannot, 
  however, 
  be 
  an 
  accurate 
  one, 
  since 
  chance 
  plays 
  an 
  im- 
  

   portant 
  role 
  in 
  the 
  collection 
  of 
  pupse, 
  and 
  only 
  by 
  a 
  comparison 
  of 
  

   several 
  generations 
  will 
  a 
  result 
  approximating 
  reality 
  be 
  obtained. 
  

   However, 
  this 
  proportion 
  probably 
  scarcely 
  remains 
  unchanged 
  in 
  the 
  

   different 
  seasons 
  of 
  the 
  year, 
  as 
  very 
  likely 
  various 
  circumstances, 
  

   such 
  as 
  unequal 
  duration 
  of 
  some 
  developmental 
  periods, 
  extraordinary 
  

   temperature, 
  &c., 
  influence 
  the 
  sexual 
  development. 
  According 
  to 
  the 
  

   table 
  given 
  that 
  proportion 
  is 
  12 
  : 
  21 
  or 
  4 
  : 
  7. 
  Hence 
  a 
  prevalence 
  of 
  

   females 
  over 
  males 
  may 
  be 
  accepted. 
  Also 
  in 
  catching 
  the 
  adults 
  in 
  

   the 
  field, 
  I 
  captured 
  a 
  larger 
  number 
  of 
  females. 
  

  

  Those 
  33 
  developed 
  flies 
  distributed 
  themselves 
  in 
  the 
  various 
  months 
  

   as 
  follows 
  : 
  August 
  6, 
  September 
  24, 
  October 
  3. 
  The 
  swarming 
  time 
  

   begins 
  toward 
  the 
  end 
  of 
  August, 
  ending 
  in 
  the 
  beginning 
  of 
  October. 
  

   The 
  points 
  of 
  time 
  of 
  the 
  beginning 
  and 
  ceasipg 
  of 
  swarming 
  essentially 
  

   depend 
  upon 
  the 
  climate 
  of 
  the 
  location 
  and 
  the 
  meteorological 
  con- 
  

   ditions 
  of 
  the 
  year. 
  The 
  climate 
  of 
  Fulda 
  is 
  under 
  the 
  predominating 
  

   influence 
  of 
  two 
  neighboring 
  mountains 
  — 
  the 
  Bhon 
  and 
  the 
  Vogel, 
  whose 
  

   foot-hills 
  approach 
  the 
  city, 
  forming 
  a 
  climatologically 
  important 
  belt 
  

   toward 
  the 
  south. 
  Our 
  district 
  rises 
  from 
  the 
  surface 
  of 
  the 
  Fulda 
  

   Eiver, 
  790 
  feet 
  up 
  to 
  1,300 
  feet 
  above 
  sea-level. 
  By 
  all 
  this 
  a 
  consider- 
  

   able 
  deviation 
  of 
  the 
  physical 
  from 
  the 
  mathematical 
  climate 
  is 
  pro- 
  

   duced, 
  which 
  must 
  influence 
  the 
  times 
  of 
  appearance 
  of 
  our 
  insect, 
  so 
  

   that 
  they 
  probably 
  also 
  correspond 
  to 
  the 
  more 
  northern 
  districts. 
  

   That 
  unfavorable 
  weather 
  produces 
  a 
  remarkable 
  retardation 
  in 
  the 
  

   development 
  of 
  insects 
  is 
  an 
  empirically 
  known 
  fact, 
  which 
  novr^adays 
  

   entomologists 
  cannot 
  deny. 
  Jjast 
  year's 
  rsiinj 
  August 
  is 
  still 
  fresh 
  in 
  

   the 
  memory 
  of 
  our 
  farmers, 
  no 
  day 
  having 
  passed 
  up 
  to 
  the 
  26th 
  without 
  

   at 
  least 
  a 
  few 
  hours 
  of 
  rain, 
  sometimes 
  even 
  lasting 
  uninterruptedly 
  for 
  

   several 
  consecutive 
  days. 
  We 
  may 
  therefore 
  assume, 
  with 
  some 
  cer- 
  

   tainty, 
  that 
  owing 
  to 
  the 
  depression 
  in 
  temperature 
  the 
  development 
  of 
  

   the 
  insect 
  was 
  retarded, 
  the 
  swarming 
  time, 
  therefore, 
  appearing 
  in 
  other 
  

   years 
  earlier. 
  

  

  The 
  life 
  of 
  the 
  imago 
  is 
  of 
  short 
  duration. 
  I 
  could 
  not 
  keep 
  the 
  flies 
  

   alive 
  longer 
  than 
  six 
  days, 
  most 
  having 
  died 
  already 
  on 
  the 
  fourth 
  or 
  

   fifth 
  day. 
  

  

  The 
  hatching 
  gall 
  -gnats 
  were 
  usually 
  not 
  leaught 
  before 
  the 
  day 
  fol- 
  

   lowing 
  hatching, 
  and 
  were 
  stux>efied 
  in 
  ether 
  vapors 
  and 
  then 
  micro- 
  

   scopically 
  examined. 
  

  

  § 
  2.^DeSCRIPTI0N 
  of 
  the 
  adult 
  INSECT 
  (iMAGO). 
  

  

  In 
  explanation, 
  I 
  premise 
  the 
  following 
  remarks 
  : 
  

  

  As 
  to 
  the 
  number 
  of 
  segments 
  constituting 
  the 
  abdomen 
  of 
  the 
  gall- 
  

   gnats 
  the 
  views 
  of 
  authors 
  are 
  at 
  present 
  still 
  divided, 
  since 
  a 
  certain 
  

   organ 
  at 
  the 
  end 
  of 
  the 
  abdomen 
  receives 
  various 
  meanings. 
  Espe- 
  

   cially 
  in 
  this 
  respect 
  do 
  the 
  views 
  of 
  those 
  two 
  German 
  dipterologists 
  dis- 
  

   agree, 
  to 
  whom 
  the 
  undeniable 
  credit 
  belongs, 
  by 
  their 
  successive 
  as 
  

  

  