﻿IN 
  AUSTRALIA. 
  39 
  

  

  Another 
  enemy 
  of 
  the 
  adult 
  sheep-maggot 
  fly 
  is 
  the 
  small, 
  metallic 
  dark 
  bronze, 
  

   sand- 
  wasp, 
  a 
  species 
  of 
  the 
  genus 
  Gorytes 
  (family 
  Nyssonidae), 
  known 
  in 
  the 
  bush 
  as 
  

   the 
  " 
  Policeman 
  Fly," 
  on 
  account 
  of 
  the 
  rapid 
  manner 
  in 
  which 
  it 
  can 
  snap 
  up 
  a 
  fly 
  

   from 
  the 
  back 
  of 
  one's 
  hand 
  with 
  its 
  powerful 
  jaws, 
  and 
  carry 
  it 
  off 
  to 
  its 
  nest. 
  The 
  

   sheep-owners 
  report 
  that 
  they 
  often 
  notice 
  these 
  wasps 
  on 
  the 
  sheep 
  catching 
  the 
  

   sheep-maggot 
  flies, 
  but 
  it 
  would 
  require 
  a 
  large 
  army 
  of 
  these 
  insects 
  to 
  do 
  much 
  

   good. 
  

  

  The 
  most 
  important 
  parasite 
  (recently 
  discovered) 
  is 
  a 
  minute, 
  metallic 
  bronzy- 
  

   green 
  Chalcid 
  wasp 
  with 
  yellow 
  legs 
  and 
  antennae 
  that 
  infests 
  the 
  larvae 
  and 
  pupae 
  

   of 
  the 
  Hairy 
  Maggot 
  (Calliphora 
  rufifacies). 
  These 
  tiny 
  little 
  parasites 
  lay 
  their 
  eggs 
  

   in 
  the 
  larva 
  or 
  pupa 
  of 
  the 
  fly, 
  and 
  from 
  a 
  large 
  number 
  of 
  pupae 
  examined 
  an 
  average 
  

   of 
  twenty 
  Chalcid 
  wasps 
  in 
  all 
  stages 
  of 
  development 
  were 
  obtained 
  from 
  each. 
  

   Many 
  thousands 
  of 
  these 
  parasites 
  have 
  been 
  bred 
  out 
  in 
  the 
  Laboratory 
  of 
  the 
  

   Experiment 
  Station 
  at 
  Yarrawin, 
  and 
  at 
  the 
  Insectarium 
  in 
  Sydney, 
  and 
  have 
  been 
  

   supplied 
  with 
  quantities 
  of 
  adult 
  fly 
  maggots 
  which 
  they 
  readily 
  parasitised 
  in 
  the 
  

   breeding 
  cages. 
  Large 
  quantities 
  of 
  these 
  parasitised 
  pupae 
  were 
  obtained 
  under 
  

   the 
  remains 
  of 
  a 
  dead 
  fowl, 
  that 
  had 
  been 
  lying 
  in 
  the 
  paddock 
  about 
  five 
  weeks 
  ; 
  

   they 
  were 
  dry 
  and 
  hard, 
  resting 
  on 
  the 
  surface 
  of 
  the 
  soil 
  under 
  the 
  decomposed 
  

   animal 
  matter, 
  among 
  a 
  number 
  of 
  empty 
  pupa 
  cases 
  from 
  which 
  the 
  sheep-maggot 
  

   flies 
  had 
  emerged. 
  

  

  The 
  importance 
  of 
  the 
  discovery 
  of 
  this 
  valuable 
  indigenous 
  parasite, 
  attacking 
  

   another 
  native 
  insect 
  under 
  natural 
  conditions, 
  and 
  that 
  can 
  be 
  readily 
  transported 
  

   and 
  bred 
  in 
  captivity, 
  can 
  hardly 
  be 
  over-estimated. 
  Here 
  there 
  is 
  every 
  condition 
  

   that 
  should 
  lead 
  to 
  the 
  balance 
  being 
  restored 
  in 
  the 
  sheep 
  paddocks, 
  particularly 
  if 
  

   we 
  can 
  assist 
  the 
  parasite 
  ; 
  for 
  the 
  chances 
  of 
  success 
  are 
  far 
  greater 
  than 
  if 
  we 
  had 
  to 
  

   depend 
  upon 
  the 
  establishment 
  of 
  an 
  introduced 
  parasite. 
  The 
  practical 
  way 
  for 
  

   our 
  sheep-owners 
  to 
  utilise 
  this 
  discovery 
  of 
  the 
  officers 
  of 
  the 
  Experiment 
  Station 
  is 
  

   for 
  them 
  to 
  examine 
  the 
  remains 
  of 
  every 
  dead 
  animal 
  they 
  find 
  in 
  going 
  round 
  these 
  

   paddocks, 
  and 
  to 
  ascertain 
  whether 
  the 
  pupae 
  of 
  the 
  sheep-maggot 
  fly 
  are 
  being 
  

   parasitised. 
  If 
  parasites 
  are 
  present, 
  the 
  pupae 
  will 
  be 
  found 
  to 
  contain 
  a 
  number 
  of 
  

   small 
  maggots 
  or 
  small 
  winged 
  ant-like 
  creatures, 
  instead 
  of 
  the 
  remains 
  of 
  a 
  single 
  

   fly. 
  In 
  that 
  case, 
  the 
  best 
  way 
  to 
  help 
  in 
  the 
  propagation 
  of 
  the 
  parasite 
  is 
  to 
  sweep 
  

   up 
  all 
  the 
  pupa 
  cases 
  found 
  under 
  the 
  remains 
  of 
  dead 
  animal 
  and 
  the 
  earth 
  just 
  under- 
  

   neath 
  (which 
  often 
  contains 
  pupae) 
  and 
  place 
  them 
  in 
  a 
  bag 
  made 
  of 
  mosquito 
  netting 
  ; 
  

   then 
  tie 
  up 
  the 
  neck 
  of 
  the 
  bag 
  and 
  hang 
  it 
  in 
  the 
  branch 
  of 
  a 
  tree 
  or 
  on 
  a 
  fence. 
  The 
  

   sheep-maggot 
  flies 
  on 
  emergence 
  from 
  the 
  pupae 
  are 
  caught 
  in 
  the 
  mesh 
  of 
  the 
  net 
  

   and 
  die, 
  while 
  the 
  smaller 
  parasites 
  can 
  easily 
  creep 
  through 
  the 
  holes 
  and 
  fly 
  away 
  

   to 
  seek 
  fresh 
  prey 
  in 
  which 
  to 
  lay 
  their 
  tiny 
  eggs. 
  

  

  At 
  the 
  time 
  of 
  our 
  discovery 
  of 
  this 
  parasite 
  in 
  the 
  North- 
  West 
  district 
  of 
  New 
  

   South 
  Wales, 
  a 
  similar 
  parasite 
  was 
  recorded 
  from 
  Longreach, 
  Central 
  Queensland, 
  

   so 
  that 
  the 
  range 
  of 
  this 
  useful 
  insect 
  may 
  be 
  very 
  wide, 
  and 
  though 
  at 
  present 
  we 
  

   know 
  little 
  of 
  its 
  habits, 
  it 
  may 
  have 
  always 
  been 
  a 
  destroyer 
  of 
  blow-fly 
  maggots. 
  

   In 
  some 
  instances 
  it 
  may 
  have 
  been 
  the 
  cause 
  of 
  the 
  marked 
  diminution 
  or 
  complete 
  

   disappearance 
  of 
  sheep-maggot 
  flies 
  that 
  has 
  sometimes 
  been 
  recorded 
  from 
  districts 
  

   which 
  were 
  previously 
  badly 
  infested. 
  

  

  