OHALCID PARASITES OF MUSCID FLIES IN AUSTRALIA. 
(5) Pachycrepoideus dubius (Girault and Sanders). 
This chalcid parasite, belonging to the Pteromalide, was recorded 
by Girault in 1913 as having been caught on windows at a number of 
North Queensland localities. It was originally described as a house- 
fly parasite in United States of America. No doubt it attacks and 
destroys various flies in Queensland. 
ReMARKS ON GERTAIN OTHER HymENnoprrrous PARASITES CAPABLE OF 
CONTROLLING THE SPREAD OF FLIES, AND WHICH MIGHT BE UTILIZED 
IN AUSTRALIA AGAINST “ Suemp-maGccor Frres.” 
Graham-Smith, in two excellent papers containing his observations 
on the habits and parasites of common flies in England (1916, 1919), 
has published interesting information regarding the Hymenoptera which 
attack fly pupe or larve, ultimately destroying them. ©The most 
important as fly-controllers seem to be Alysia manducator, Aphereta 
cephalotes Hal. (both belonging to the Braconide), and Melittobia acasta 
Walker (Chalcidide). = pet 
Alysia manducator.—Graham-Sinith’s observations on this rela- 
tively large Braconid, which is as long as-a house fly, show that it is 
fairly common in England, parasitizing as many as 83 per cent. of fly 
pup collected at certain times, especially during autumn. He stated 
that—* These facts reveal the extraordinary destruction wrought by 
these parasites, and indicate that larvee feeding in warm and sunny situa- 
tions are more liable to attack than those living in shady places.” The 
female, which lives only a few days in confinement, attacks and ovi- 
posits in larger living larvee, not waiting for them to pupate. In one © 
experiment, this author found that a female deposited eggs in at least 
206 out of 544 larve provided; that 80 other larvme died, possibly due 
to infection caused by the insertion of the ovipositor; and that no less. 
than 348 eggs were still contained in the wasp’s ovaries. “ Under more 
natural conditions, it is likely that she would haye infected a greater 
number, as the ovaries contained at least 549 eggs.” This wasp over-— 
winters as a pupa, emerging in the spring. Its habits should make it a 
very desirable insect for use against sheep-maggot flies in Australia. 
Aphereta cephalotes (Hal.)—This is a much smaller Braconid, 
béing only half the length of the preceding wasp. From each parasi- 
tized blowfly pupa a number (7 to 14) of these insects have been bred 
out. The species appears to prefer sunny situations for oviposition, 
small larve being selected. for the purpose. It passes through the 
winter while within the fly puparium. .From the information available, 
. it does not seem to be as valuable a fly-controller as the preceding 
species (Graham-Smith, 1916, 1919). 
Melittobia acasta (Walker).—This is a tiny Braconid, whose habits 
are described in an interesting account by the same author. There 
is a very marked sexual dimorphism, the males possessing rudimentary 
wings and eyes, as well as peculiarly modified antenne. The female can 
live in confinement for a long period (33 to 86 days—95 the maximum . 
noted), and lay up to 300 eggs. The males are short-lived, and do not 
leave the puparium in which they have been developed. 
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