﻿453 
  

  

  ON 
  AN 
  INTERNAL 
  PARASITE 
  (HYM.-CHALCIDOIDEA) 
  OF 
  

   A 
  THRIPS 
  FROM 
  TRINIDAD. 
  

  

  By 
  James 
  Waterston, 
  B.D., 
  D.Sc. 
  

  

  During 
  the 
  past 
  summer 
  Mr. 
  F. 
  W. 
  Urich, 
  Government 
  Entomologist, 
  Trinidad, 
  

   B.W.I. 
  , 
  succeeded 
  in 
  rearing 
  a 
  number 
  of 
  small 
  Chalcids 
  from 
  larvae 
  of 
  a 
  thrips 
  in 
  

   the 
  prepupal 
  stage. 
  The 
  following 
  description 
  is 
  based 
  on 
  part 
  of 
  this 
  material. 
  

  

  An 
  examination 
  of 
  this 
  Chalcid 
  emphasises 
  the 
  chaotic 
  condition 
  of 
  the 
  classi- 
  

   fication 
  of 
  the 
  subfamily 
  (Tetrastichinae) 
  to 
  which 
  it 
  belongs. 
  For 
  the 
  present 
  

   it 
  may 
  be 
  placed 
  in 
  the 
  genus 
  Tetrastichus, 
  Hal. 
  Amongst 
  its 
  noteworthy 
  features 
  

   are 
  (a) 
  the 
  shape 
  and 
  sculpture 
  of 
  the 
  head 
  and 
  the 
  mandible 
  ; 
  (b) 
  the 
  swollen 
  junction 
  

   of 
  the 
  veins 
  of 
  the 
  fore-wing 
  ; 
  (c) 
  the 
  structure 
  of 
  the 
  propodeon 
  ; 
  (d) 
  the 
  short 
  

   ovipositor 
  and 
  somewhat 
  abrupt 
  reduction 
  of 
  the 
  posterior 
  segments. 
  

  

  Fig. 
  1. 
  Tetrastichus 
  thripophonns, 
  Wtrst., 
  sp. 
  n. 
  : 
  a, 
  head 
  ; 
  b, 
  clypeus 
  and 
  labrum 
  ; 
  c, 
  mandible 
  

  

  d, 
  fore-wing. 
  

  

  Genus 
  Tetrastichus. 
  

   Tetrastichus 
  thripophonus, 
  sp. 
  n. 
  

  

  $.— 
  A 
  moderately 
  shining, 
  blackish 
  brown 
  species, 
  with 
  legs, 
  antennae 
  and 
  a 
  

   large 
  basal 
  abdominal 
  blotch 
  pale. 
  Head 
  dull 
  dark 
  brown. 
  Thorax 
  darkest, 
  with 
  

   faint 
  purplish 
  reflections. 
  The 
  basal 
  abdominal 
  spot 
  extends 
  both 
  dorsally 
  and 
  

   ventrally 
  over 
  two 
  segments. 
  Antennae 
  with 
  scape 
  yellowish 
  ; 
  pedicel 
  sometimes 
  

   a 
  little 
  embrowned 
  dorsally 
  at 
  base 
  ; 
  funicle 
  and 
  legs 
  (except 
  coxae) 
  yellowish 
  brown. 
  

   Coxae 
  infuscated 
  (decidedly 
  so 
  in 
  hind 
  legs) 
  but 
  indistinctly 
  and 
  narrowly 
  pale 
  at 
  

   apex. 
  Wings 
  hyaline, 
  nervures 
  brown. 
  In 
  the 
  fore-wings 
  there 
  is 
  an 
  extremely 
  

   narrow 
  darker 
  line 
  connecting 
  the 
  bases 
  of 
  the 
  fringing 
  cilia 
  and 
  throwing 
  the 
  latter 
  

   more 
  into 
  relief. 
  

  

  (8455) 
  

  

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