118 



duration of the pupal stage of flies reared in the laboratory was 36, 

 37 and 38 days respectively. In its general form the egg of this species 

 strongly resembles that of Gastrophilus equi. 



Takatsuki (A.). Mosquito Control by means of Petroleum.— /iTiyo/o 



Jl. Med. Sci., Kyoto, xiv, no 7, 20th November 1917, pp. 117-118. 

 (Abstract in China Med. Jl.,ShafiqJiai, xxxiu, no. 2, March 1919, 

 p. 166.) [Received 5th May 1919.] 



The action of heavy mineral oils on mosquito larvae is not so much 

 a mechanical process of obstructing the breathing pores of the immature 

 stages as a rather acute intoxication. Other oils that are relatively 

 inert, such as rape-seed oil, etc., do not cause death nearly so readily. 

 The author finds that the breathing siphon does not stain with ordinary 

 water-soluble dyes, but is intensely coloured by Sudan III suspended 

 in petroleum, from which he concludes that some fat-like substance 

 is present in that organ which combines with the petroleum to the 

 injury of the body as a whole. 



According to this hypothesis, there is needed, perhaps, 26 mils of 

 oil per sq. metre of water surface instead of 1/4| [sic] litres as 

 usually recommended. An emulsion makes the spreading much more 

 efficient. It is unfortunate, however, that both larvae and pupae 

 in late autumn were found to be more resistant to the oil than those 

 developed earlier in the summer. 



Hill (G. F.). Relationship of Insects to Parasitic Diseases in Stock. — 

 Proc. R.'Soc. Victoria, Melbourne, xxxi, no. 1, December 1918, 

 pp. 11-107, 7 plates. [Received 5th May 1919.] 



The first part of this paper deals with the life-history of Habronema 

 muscae, which has been known for some years as the result of investi- 

 gations made in the United States, and with those of H. microstoma 

 and H. ?negastoma, nothing concerning which is definitely known 

 in Australia or elsewhere. Such knowledge has become important 

 owing to the belief that the larvae of Habronema are the causative 

 agents of disease in the horse, and that splenic and stomach abscesses 

 due to H. megastoma have been of more frequent occurrence in Australia 

 during the past few years, the mortality caused in stock under certain 

 conditions being considerable. 



As a result of numerous experiments, the details of which are given, 

 it was found that the embryos of H. muscae that are passed out in 

 the faeces of the horse, are taken up by the larvae of Musca domestica, 

 reared from eggs deposited by adults on them. These remain infective 

 in this respect up to at least 8 days after leaving the rectum, and the 

 fly larvae are known to react to infection when from 48 hours to 9 days 

 old. After a slight amount of development in the faeces, the embryo 

 of H. muscae enters the larva of M. domestica, where it continues to 

 develop through its various stages until in the adult fly it is ready 

 to develop in the stomach of the horse, where such stages have been 

 met with. 



The infection of the horse probably takes place by the ingestion 

 of both living and dead infected flies, it being beyond question that 

 these are quite commonly ingested by horses from drinking troughs 

 and mangers. In summer the fodder is frequented by great nu^mbers. 



