﻿IMPERIAL 
  BUREAU 
  OF 
  ENTOMOLOGY. 
  

  

  BULLETIN 
  

  

  OF 
  

  

  ENTOMOLOGICAL 
  RESEARCH. 
  

  

  Vol. 
  X. 
  1919. 
  

  

  A 
  NEW 
  AUSTRALIAN 
  SPECIES 
  OF 
  RIOXA, 
  WITH 
  A 
  REMARKABLE 
  LIFE- 
  

   HABIT 
  (DIPT. 
  ; 
  TRYPANEIDAE). 
  

   By 
  Prof. 
  M. 
  Bezzi, 
  

  

  Turin, 
  Italy. 
  

   Dr. 
  Guy 
  A. 
  K. 
  Marshall 
  has 
  recently 
  submitted 
  to 
  me 
  a 
  Trypaneid, 
  discovered 
  in 
  

   Northern 
  Australia 
  by 
  Mr. 
  G-. 
  F. 
  Hill. 
  The 
  fly 
  is 
  said 
  to 
  have 
  been 
  bred 
  from 
  larvae 
  

   having 
  habits 
  very 
  different 
  from 
  those 
  of 
  the 
  related 
  members 
  of 
  the 
  family 
  ; 
  and 
  

   being 
  moreover 
  interesting 
  from 
  a 
  morphological 
  and 
  biogeographical 
  standpoint, 
  

   it 
  forms 
  the 
  object 
  of 
  the 
  present 
  note. 
  

  

  The 
  Oriental 
  species 
  of 
  Ceeatitinae 
  with 
  6 
  bristles 
  on 
  the 
  scutellum, 
  with 
  a 
  

   complete 
  thoracic 
  chaetotaxy, 
  with 
  a 
  bristly 
  third 
  longitudinal 
  vein, 
  with 
  a 
  not 
  wavy 
  

   second 
  longitudinal 
  vein, 
  and 
  with 
  a 
  wing-pattern 
  consisting 
  of 
  an 
  extended 
  brown 
  

   patch 
  with 
  hyaline 
  spots 
  and 
  hyaline 
  indentations, 
  have 
  been 
  ascribed 
  by 
  me* 
  to 
  

   the 
  two 
  genera 
  Diarrhegma 
  and 
  Rioxa. 
  While 
  the 
  first 
  of 
  these 
  genera 
  is 
  less 
  

   numerous 
  and 
  is 
  well 
  characterised 
  by 
  the 
  form 
  of 
  the 
  head, 
  the 
  second 
  contains 
  

   heterogeneous 
  elements, 
  which 
  have 
  been 
  divided 
  by 
  me 
  into 
  three 
  groups. 
  Fol- 
  

   lowing 
  on 
  this, 
  Prof. 
  Hendelf 
  erected 
  the 
  new 
  genus 
  Hexacinia 
  for 
  the 
  peculiar 
  

   group 
  of 
  stellata, 
  Macq., 
  and 
  divided 
  the 
  remaining 
  species 
  into 
  the 
  genera 
  Rioxa 
  

   (with 
  a 
  pectinate 
  arista) 
  and 
  Rioxovtilona 
  (with 
  a 
  plumose 
  arista). 
  But 
  this 
  last 
  

   distinction 
  seems 
  to 
  be 
  a 
  premature 
  one, 
  as 
  it 
  is 
  impossible 
  to 
  draw 
  a 
  sharp 
  line 
  of 
  

   separation 
  between 
  the 
  species 
  in 
  which 
  the 
  arista 
  is 
  plumose 
  on 
  the 
  upper 
  side 
  alone, 
  

   and 
  those 
  in 
  which 
  it 
  is 
  plumose 
  on 
  both 
  sides. 
  

  

  I 
  have 
  before 
  me 
  two 
  species 
  of 
  Australian 
  Teypaneidae 
  which 
  are 
  referable 
  to 
  

  

  the 
  genus 
  Rioxa, 
  s.l. 
  ; 
  they 
  closely 
  resemble 
  one 
  another 
  both 
  in 
  body 
  coloration 
  

  

  and 
  wing 
  markings, 
  but 
  may 
  be 
  distinguished 
  as 
  follows 
  : 
  — 
  

  

  1(2). 
  Two 
  upper 
  and 
  two 
  lower 
  pairs 
  of 
  orbital 
  bristles 
  present 
  ; 
  arista 
  regularly 
  

  

  pilose, 
  with 
  some 
  short 
  hairs 
  only 
  on 
  the 
  under 
  side 
  ; 
  mesonotum 
  and 
  

  

  scutellum 
  without 
  dark 
  spots, 
  the 
  latter 
  with 
  the 
  middle 
  pair 
  of 
  bristles 
  

  

  weaker 
  than 
  the 
  others 
  ; 
  discoidal 
  cell 
  with 
  two 
  hyaline 
  spots, 
  which 
  are 
  

  

  confluent 
  with 
  the 
  hyaline 
  indentations 
  of 
  the 
  hind 
  border 
  

  

  musae, 
  Froggatt 
  

  

  * 
  Mem. 
  Ind. 
  Mus., 
  Calcutta, 
  1913, 
  iii, 
  pp. 
  53-175, 
  pi. 
  viii-x 
  (vide 
  pp. 
  108 
  and 
  111 
  

   t 
  Wien. 
  Ent. 
  Zeit., 
  1914, 
  xxxiii, 
  pp. 
  73-98 
  (vide 
  pp. 
  78 
  and 
  82). 
  

   (C572) 
  P4|140. 
  1,000. 
  10.19. 
  B.&F.Ltd. 
  G.ll. 
  a 
  

  

  