CMALCID PARASITES OF AUSTRALIAN SHEEP MAGGOT-FLIES. 105 



The total period from egg deposition to the emergence 

 of the wasp was 21 to 28 days during midsummer, and never 

 more than one wasp developed from a single pupa (Jolmston 

 and Bancroft, 1920). With Sarcophaga impatiens during 

 February the period varied considerably, being between 23 

 and 30 days ; and no more than one wasp appeared from even 

 these large pupae. 



This chalcid appears to be widely distributed over Southern 

 Queensland, though probably not common. 



4, Dirhinus sarcophagse Froggatt. (Figs. 2, 10, 23, 24, 34.) 



This wasp was iirst described and figured by Froggatt 

 (1919), who bred it from pupae of Sarcophaga aurifrons Macq. 

 It occurs also in Brisbane and is most common about February. 

 It will parasitize any of the common sheep-fly pupae, Pycnosoma 

 (both species), Lucilia spp., and Sarcophaga spp. being readily 

 attacked. During oviposition the wasp assumes a most 

 remarkable, uncouth attitude (fig. 2), remaining in this position 

 for about fifteen minutes, and seems obHvious to everything 

 going on around it, so that the pupa with the parasitizing 

 Avasp can readily be lifted without disturbing the latter. After 

 oviposition is completed the wasp settles on the pupa in a 

 crouching attitude for a long time, and then wanders off, 

 usually to attack another. 



The egg measures -68 mm in length and -17 in breadth 

 (fig. 34). The egg period has not been observed. The maggot 

 is a large whitish legless creature (fig. 23 ; Froggatt, 1919, 

 p. 854, fig. 1) which feeds on the outside of the fly-nymph 

 just as Nasonia does. It measure from 3 to 4 mm. in length. 



The third instar does not appear to possess jaws. Its 

 head is a curious structure and is provided with two prominent 

 lips (fig. 10), the action of which causes the liquid contents 

 of the disintegrating fly larva to flow into the mouth. The 

 larvae appear to be predaceous ; for on several occasions two 

 larvae were found within a fly-pupa, yet not more than one 

 wasp was observed to emerge from each fly-pupa. The wasp- 

 pupa is a large white creature (fig. 24), with the characteristic 

 Dirhinus appearance. The pupal period has not been deter- 

 mined but it is more than 7 days. The total period from ovi- 

 position to emergence during November, 1920, was found to 

 be 25 days ; but during January, 1921, as much as 28 days. 



