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MR. A. M. ALTSON OX THE LIFE-HISTORY AND 



The hosts reported from America bv Giraiilt and Saunders (6) 

 are : — 



Musca domestica Linn. 

 Calliphora erythrocejyhala Meig. 

 Phormia regina Linn. 

 Lacilia ccesar Linn. 



,, sericata Meig. 

 Chrysomia macellaria Fabr. 

 Cyitomyia cadaveinnia Desv. 

 ^arcofihaga' species " K " (Spec. nov?i). 



The liosts reported from Australia by Fi'oggatt, jun. (7) are as 

 follows : — 



Fycnosoma rihfi fades. " Mostly in tlie field." 



,, vari2)es. " To a lesser extent in the field." 



Anastellorhina augur. ^ 

 Pollenia stygia. I 



Lucilia sericata. > "In the laboratory." 



Calliphora erythrocephala. I 

 ^arcophaga aurifrons. ^ 



Super-parasitism, or Accidental Secondary Parasitism. 



That JSfasonia hreiiicorrds might be a " Hyperparasite " upon 

 Alysia maiuhicator originally occurred to the writer, when the 

 second lot of puparia were collected from the spot at E-egent's Park 

 whence the original Braconid parasitized material was obtained, 

 and when it was found that this Chalcid was emerging from it. 

 However, no Braconid lining to the puparia was observed, at the 

 time, in any from which the Clialcids had emerged ; and as the 

 initial breeding operations showed that the latter — then undeter- 

 mined — bred freely from healthy host puparium, it was assumed 

 that " hyperparasitism " was not the role of JV. hrevicornis ; 

 although it appeared reasonable to suppose that the Chalcid 

 might act accidentally as a secondary parasite in the early stages 

 of development of the Braconid — that is, during the first or 

 second instar — and when the greater part of the fly-nymph still 

 existed. That secondary parasitism in this early stage could 

 take place appears probable ; and it does not require a great 

 stretch of imagination to conceive the race for life within a 

 puparium, in the fly-nymph of which an early instar larva of the 

 Braconid is slowly feeding, when suddenly one by one a dozen, 

 more or less, Chalcid larvie commence feeding operations from 

 the outside of, and through the enveloping integument of the fly- 

 nymph. That the result of such an unequal contest would be 

 against the Braconid, it seems only reasonable to assume ; and 

 that the latter would eventually be killed by the Chalcids biting 

 into it. No efforts were made to investigate this point; it 

 appeared too obvious a potentiality, and to search the remnants 



