﻿328 
  

  

  JAMES 
  WATERSTON. 
  

  

  Thorax 
  with 
  coxae 
  and 
  propodaeum 
  dark 
  metallic 
  green, 
  notal 
  and 
  pleural 
  surfaces 
  

   entirely 
  evenly 
  and 
  moderately 
  raised, 
  reticulate. 
  

  

  Legs 
  transparent 
  yellow, 
  with 
  a 
  slight 
  tinge 
  of 
  brown 
  on 
  femora 
  ; 
  the 
  fifth 
  tarsal 
  

   joints 
  and 
  claws 
  blackish 
  brown. 
  

  

  Abdomen 
  not 
  triangular, 
  but 
  swollen, 
  spindle-shaped, 
  very 
  dark 
  and 
  smooth, 
  three- 
  

   fourths 
  formed 
  by 
  the 
  large 
  second 
  and 
  third 
  segments. 
  Petiole 
  long, 
  extending 
  

   to 
  the 
  distal 
  end 
  of 
  the 
  trochanter. 
  

  

  Length, 
  1| 
  mm. 
  ; 
  alar 
  expanse, 
  over 
  3 
  mm. 
  

  

  Host 
  : 
  the 
  bean 
  fly 
  (Agromyza 
  phaseoli, 
  Coq.). 
  

  

  Described 
  from 
  a 
  series 
  of 
  3 
  <?<? 
  and 
  2 
  $?. 
  

  

  Holotype 
  — 
  a 
  (J. 
  

  

  Trigonogastra 
  megacephala, 
  sp. 
  nov. 
  (fig. 
  2). 
  

  

  (J. 
  — 
  Head 
  large 
  and 
  broad, 
  with 
  wide 
  frons 
  and 
  vertex, 
  closely 
  punctate 
  or 
  reticu 
  

   late, 
  gleaming 
  or 
  shining, 
  and 
  nowhere 
  metallic. 
  Colour 
  almost 
  black, 
  with 
  greenish 
  

   tinge 
  on 
  the 
  frons 
  and 
  purplish 
  on 
  occiput 
  and 
  vertex. 
  The 
  head 
  of 
  the 
  single 
  <J 
  is 
  

   so 
  embedded 
  in 
  the 
  fixative 
  as 
  to 
  render 
  comparative 
  measurements 
  of 
  length 
  and 
  

   breadth 
  unsafe. 
  

  

  Antennae 
  (fig. 
  2, 
  a) 
  similar 
  to 
  those 
  of 
  T. 
  rugosa, 
  (J, 
  but 
  the 
  joints 
  are 
  not 
  longer 
  

   than 
  broad, 
  and 
  much 
  more 
  sparsely 
  haired. 
  The 
  antennae 
  as 
  a 
  whole 
  are 
  rather 
  

   short 
  and 
  dark, 
  the 
  scape 
  being 
  lighter. 
  Scape 
  four-and-a-half 
  times 
  as 
  long 
  as 
  

   broad, 
  pre-apically 
  a 
  little 
  expanded. 
  Pedicel, 
  a 
  little 
  over 
  one-third 
  of 
  the 
  scape 
  

   and 
  hardly 
  longer 
  than 
  broad. 
  Two 
  ring 
  joints, 
  the 
  first 
  narrower 
  and 
  shorter 
  

   than 
  the 
  second. 
  First 
  funicular 
  joint 
  square, 
  narrower 
  than 
  the 
  others 
  (4 
  : 
  5), 
  

   second 
  joint 
  longer 
  than 
  broad, 
  3 
  to 
  6 
  square. 
  The 
  club 
  is 
  a 
  little 
  expanded, 
  

   but 
  not 
  very 
  appreciably, 
  with 
  joints 
  in 
  the 
  proportion, 
  10 
  : 
  9 
  : 
  8. 
  There 
  are 
  few 
  

   sensoria 
  ; 
  the 
  second 
  and 
  third 
  joints 
  have 
  one 
  each 
  ; 
  the 
  fourth 
  and 
  fifth, 
  two 
  each 
  ; 
  

   the 
  sixth 
  has 
  four 
  and 
  the 
  club 
  joints 
  four, 
  two, 
  one 
  respectively. 
  Length 
  of 
  antenna, 
  

   •65 
  mm. 
  

  

  Fig. 
  2. 
  Trigonogastra 
  megacephala, 
  sp. 
  n. 
  ; 
  a, 
  antenna 
  of 
  $ 
  ; 
  b, 
  antenna 
  of 
  $. 
  

  

  Thorax 
  broad 
  and 
  depressed, 
  with 
  the 
  dark 
  purple 
  colour 
  of 
  the 
  head 
  and 
  the 
  same 
  

   reticulation 
  ; 
  the 
  pattern 
  on 
  the 
  scutellum 
  finer 
  than 
  in 
  front 
  of 
  the 
  suture. 
  Meta- 
  

   thorax 
  gleaming, 
  purplish 
  blue 
  ; 
  propodaeum 
  entirely 
  reticulate, 
  dull. 
  

  

  