﻿46 
  PROCEEDINGS 
  OF 
  THE 
  NATIONAL 
  MUSEUM 
  vol. 
  67 
  

  

  30. 
  MICROBRACON 
  TENUICEPS, 
  new 
  species 
  

  

  Fig. 
  7 
  

  

  Very 
  similar 
  in 
  structure 
  to 
  rudbeckiae, 
  but 
  is 
  almost 
  completely 
  

   black, 
  has 
  the 
  second 
  abdominal 
  tergite 
  wholly 
  smooth 
  and 
  polished, 
  

   and 
  differs 
  in 
  numerous 
  details 
  ; 
  also 
  resembles 
  nuperus, 
  but 
  differs 
  as 
  

   noted 
  in 
  the 
  key. 
  

  

  Female. 
  — 
  Length, 
  3 
  mm. 
  Head 
  thin 
  antero-posteriorly, 
  scarcely 
  

   thicker 
  at 
  insertion 
  of 
  antennae 
  than 
  at 
  the 
  clypeus, 
  the 
  face 
  not 
  or 
  

   hardly 
  receding; 
  the 
  frons 
  almost 
  vertical; 
  face, 
  frons, 
  vertex, 
  and 
  

   temples 
  smooth 
  and 
  polished; 
  eyes 
  nearly 
  twice 
  as 
  long 
  as 
  broad, 
  

   faintly 
  hairy; 
  transverse 
  diameter 
  of 
  opening 
  between 
  clypeus 
  and 
  

   mandibles 
  not 
  twice 
  the 
  length 
  of 
  the 
  malar 
  space; 
  post-ocellar 
  Hue 
  

   not 
  distinctly 
  twice, 
  the 
  ocell-ocular 
  line 
  not 
  distinctly 
  three 
  times, 
  

   as 
  long 
  as 
  the 
  diameter 
  of 
  an 
  ocellus; 
  antennae 
  23-segmented, 
  the 
  

   basal 
  flagellar 
  segment 
  nearly 
  three 
  times 
  as 
  long 
  as 
  broad, 
  the 
  

   following 
  gradually 
  decreasing 
  in 
  length, 
  but 
  most 
  of 
  them 
  fully 
  

   twice 
  as 
  long 
  as 
  broad 
  ; 
  thorax 
  rather 
  stout, 
  completely 
  smooth 
  and 
  

   polished 
  ; 
  parapsidal 
  furrows 
  sparsely 
  hairy 
  anteriorly, 
  more 
  thickly 
  

   so 
  posteriorly 
  ; 
  propodeum 
  entirely 
  polished, 
  without 
  even 
  a 
  stub 
  of 
  

   a 
  median 
  longitudinal 
  ridge 
  at 
  apex; 
  first 
  abscissa 
  of 
  radius 
  longer 
  

   than 
  the 
  recurrent 
  vein 
  ; 
  second 
  abscissa 
  of 
  radius 
  much 
  less 
  than 
  twice 
  

   the 
  first, 
  only 
  half 
  the 
  third, 
  and 
  but 
  very 
  slightly 
  longer 
  than 
  the 
  

   first 
  intercubitus 
  ; 
  radius 
  attaining 
  wing 
  margin 
  distinctly 
  before 
  the 
  

   apex; 
  last 
  abscissa 
  of 
  cubitus 
  a 
  little 
  longer 
  than 
  the 
  preceding 
  ab- 
  

   scissa 
  ; 
  legs 
  slender, 
  the 
  posterior 
  femora 
  at 
  least 
  four-fifths 
  as 
  long 
  as 
  

   their 
  tibiae 
  ; 
  abdomen 
  about 
  as 
  long 
  as 
  the 
  thorax, 
  completely 
  smooth 
  

   and 
  highly 
  polished; 
  the 
  chitinized 
  plate 
  of 
  first 
  tergite 
  broad, 
  and 
  

   with 
  two 
  fine 
  impressed 
  curved 
  lines 
  converging 
  toward 
  base; 
  sec- 
  

   ond 
  abdominal 
  tergite 
  with 
  a 
  small 
  but 
  conspicuous, 
  more 
  or 
  less 
  tri- 
  

   angular, 
  membranous 
  area 
  at 
  either 
  side 
  joining 
  the 
  lateral 
  membran- 
  

   ous 
  margins 
  of 
  the 
  first 
  tergite 
  ; 
  second 
  tergite 
  much 
  shorter 
  than 
  the 
  

   third 
  ; 
  hypopygium 
  attaining 
  apex 
  of 
  last 
  dorsal 
  abdominal 
  segment 
  ; 
  

   ovipositor 
  sheaths 
  fully 
  as 
  long 
  as 
  the 
  entire 
  body. 
  Black 
  ; 
  head 
  and 
  

   thorax 
  wholly 
  black; 
  wings 
  strongly 
  infuscated; 
  legs 
  deep 
  black, 
  

   except 
  the 
  anterior 
  femora 
  at 
  apex, 
  their 
  tibiae 
  within, 
  and 
  the 
  

   middle 
  and 
  posterior 
  tibiae 
  at 
  extreme 
  base, 
  where 
  they 
  are 
  brownish 
  ; 
  

   abdomen 
  black 
  except 
  the 
  membranous 
  margins 
  along 
  first 
  tergite, 
  

   the 
  membranous 
  areas 
  in 
  the 
  basal 
  lateral 
  angles 
  of 
  the 
  second, 
  and 
  

   a 
  very 
  small 
  spot 
  in 
  the 
  basal 
  lateral 
  angles 
  of 
  the 
  third, 
  which 
  are 
  

   bright 
  yellow, 
  contrasting 
  strongly 
  with 
  the 
  deep 
  black 
  of 
  the 
  re- 
  

   mainder 
  of 
  the 
  abdomen. 
  

  

  Type.— 
  Cat. 
  No. 
  27142, 
  U.S.N.M. 
  

  

  Type-locality. 
  — 
  Chester, 
  Virginia. 
  

  

  Host. 
  — 
  f 
  Phytonomus 
  nigrirostris 
  Fabricius. 
  

  

  