CHALCID PARASITES OF A[-STRALIAN SHEEP MAGGOT-FLIES. 107 



8. Chalcis dipterophaga Girault and Docld. 

 Syn. : C. calliphorce Johnston 1921 (from Brisbane). 



This rather large wasp, which seems to differ from C. calli- 

 phorce only in the lighter colouration of the antennae and 

 abdomen, AA^as found on one occasion in Brisbane to be 

 attracted to blowfly maggots. There is little doubt that the 

 species is a parasite of the latter. Girault (1915) reported that 

 this Chalcid Avas bred from dipterous puparia in North 

 Queensland. 



9. Australencyrtus giraulti Johnston and Tiegs. 

 (Figs. 1, 9, 11-17, 25-2G.) 

 This Encyrtid wasp, of which a description is giA^en at 

 the end of the paper, was first discovered attacking sheepfly 

 maggots in Brisbane in October, 1920. It was soon found that 

 it could be bred AAith comparatiA^e ease and in large numbers. 

 On one occasion many thousand individuals AAere obtained 

 after several generations from a single female. During Feb- 

 ruary, 1921, the wasp AAas again seen in the open, AA'hile during 

 April it was quite common around decaying meat. A few 

 specimens were seen during July, 1921. 



The female attacks all the common sheep bloAA'flies in 

 their larval state, seeming to prefer smooth maggots {Chry- 

 somyia dux, Lucilia spp., Paracalliphora augur), but AA'ill quite 

 readily attack the " hairy " Pycnosoma larvae (P. riififacies 

 and P. varipes) as aa^cU as those of the thick-skinned Sarcophaga 

 spp. The wasps are exceedingly actiA^e, especially the females, 

 Avhich settle on any part of the maggots (fig. 1), and immediately 

 begin to OAdposit after shoAving great dexterity in cHnging to 

 the maggot as the latter crawls or wriggles. As a rule they 

 do^ not appear to hurt the maggot in any Avay during the 

 operation, though sometimes the latter is seen to Avrithe a 

 little, no doubt when the oAdpositor happens to injure a nerve. 



Under artificial conditions numerous wasps commonly 

 attack a maggot at once. When some decaying meat is exposed 

 these wasps can often be seen close to the living maggots, 

 and they will cA^en attempt to parasitize those AA'hich are 

 wrigghng about immediately beneath the soil. OA^position 

 lasts from a quarter to half a minute, but at times Avhen the 

 maggot is quiet it will take considerably longer. Usually about 

 seven eggs appear to be laid at each act of OA^iposition. Some- 

 times as many as twenty-nine wasps emerge from a pupa 

 (artificially infected, probably by seA^eral Avasps), the insects 



