﻿66 
  

  

  21 
  (18) 
  Apical 
  margin 
  of 
  second 
  segment 
  not 
  red. 
  

   21a(21b) 
  Basal 
  abdominal 
  segment 
  nearly 
  entirely 
  red. 
  

  

  O. 
  microdemas 
  P. 
  

   21b(21a) 
  Basal 
  abdominal 
  segment 
  with 
  an 
  apical 
  red 
  band, 
  sometimes 
  

   interrupted. 
  O. 
  monobius 
  var. 
  

  

  Propodeum 
  black. 
  

  

  Propodeum 
  rugose. 
  O. 
  erythrostactes 
  P. 
  

  

  Propodeum 
  smooth 
  or 
  punctured. 
  

  

  Propodeum 
  smooth, 
  impunctate 
  or 
  nearly 
  so. 
  O. 
  montivagus 
  P. 
  

   Propodeum 
  densely 
  punctured 
  in 
  the 
  concavity. 
  

  

  O. 
  monobius 
  P. 
  

   Prothorax 
  not 
  red-marked. 
  

   Second 
  abdominal 
  segment 
  with 
  a 
  red 
  apical 
  band. 
  

  

  O. 
  sandwichensis 
  , 
  de 
  S. 
  (O. 
  rubritinctus, 
  Sm) 
  

   Second 
  segment 
  without 
  a 
  red 
  apical 
  band. 
  O. 
  petrobius, 
  P. 
  

  

  Abdomen 
  without 
  red 
  markings, 
  and 
  the 
  mesopleura 
  withotU 
  a 
  

   red 
  spot 
  beneath 
  the 
  tegulae. 
  

  

  31 
  (40) 
  Costae 
  of 
  second 
  ventral 
  segment 
  of 
  abdomen 
  largely 
  effaced 
  

  

  and 
  indistinct, 
  or 
  altogether 
  wanting, 
  the 
  transverse 
  

   sulcature 
  often 
  smooth 
  and 
  shining, 
  the 
  abdomen 
  never 
  with 
  

   two 
  yellow 
  bands. 
  

  

  32 
  (33) 
  A 
  median 
  red 
  frontal 
  spot 
  on 
  the 
  face, 
  and 
  the 
  prothorax 
  always 
  

  

  red-marked, 
  second 
  segment 
  of 
  abdomen 
  above 
  simple, 
  not 
  

   at 
  all 
  strongly 
  convex 
  or 
  raised 
  from 
  the 
  base, 
  beneath 
  

   greatly 
  and 
  abruptly 
  raised 
  behind 
  the 
  sulcature. 
  

  

  O. 
  deinogaster, 
  P. 
  

  

  33 
  (32) 
  No 
  red 
  frontal 
  spot 
  on 
  face, 
  the 
  prothorax 
  at 
  most 
  indistinctly 
  

  

  reddish 
  along 
  the 
  hind 
  margin, 
  second 
  segment 
  above 
  

   always 
  more 
  or 
  less 
  strongly 
  raised 
  from 
  the 
  base 
  or 
  strongly 
  

   convex 
  in 
  profile; 
  beneath 
  of 
  various 
  forms. 
  

  

  34 
  (37) 
  Second 
  ventral 
  segment 
  raised 
  from 
  the 
  sulcature 
  to 
  a 
  height 
  

  

  very 
  much 
  greater 
  than 
  that 
  of 
  its 
  basal 
  portion. 
  

  

  35 
  (36) 
  Propodeum 
  smooth, 
  shining; 
  apex 
  of 
  clypeus 
  red 
  

  

  O. 
  purpurifer, 
  P. 
  

  

  36 
  (35) 
  Propodeum 
  not 
  smooth 
  and 
  shining, 
  but 
  punctate 
  or 
  subrugose 
  

  

  apex 
  of 
  clypeus 
  not 
  red. 
  O. 
  instabilis, 
  P. 
  

  

  37 
  (34) 
  Second 
  ventral 
  segment 
  of 
  abdomen 
  (seen 
  in 
  profile) 
  raised 
  

  

  behind 
  the 
  sulcature 
  only 
  to 
  about 
  the 
  height 
  of 
  its 
  basal 
  

   portion 
  or 
  a 
  little 
  higher. 
  

  

  38 
  (39) 
  Second 
  ventral 
  segment 
  with 
  a 
  rather 
  wide 
  depression 
  behind 
  

  

  the 
  sulcature. 
  O. 
  ecostatus, 
  P. 
  

  

  39 
  (38) 
  Second 
  ventral 
  segment 
  with 
  a 
  narrow 
  depression. 
  

  

  pp 
  O. 
  laevisulcatus, 
  P. 
  

  

  40 
  (31) 
  Transverse 
  sulcature 
  of 
  second 
  ventral 
  segment 
  with 
  distinct 
  

  

  costae, 
  never 
  smooth 
  and 
  shining; 
  if 
  the 
  costae 
  are 
  more 
  or 
  

   less 
  obsolete 
  the 
  abdomen 
  has 
  two 
  yellow 
  bands. 
  

  

  41 
  (42) 
  A 
  median 
  frontal 
  spot 
  and 
  the 
  tegulae 
  always, 
  other 
  markings 
  

  

  sometimes 
  red. 
  O. 
  camelinus, 
  P. 
  

  

  