46 



abated under proper treatment and preventive measures. It is 

 ]jroljably nut endemic in the Territory, the outbreak in question being 

 ]jrobably due to the influx of infected individuals fi'om New Guinea, 

 Patagonia and North Queensland. 



The Culicid, Taeniorhynchus brevicellulus {Chrysoconops acer), has 

 been bred out from larvae obtained from bathroom drainage on 

 premises in Darwin. There has been an increase in the Dytiscid 

 beetle predaceous on mosquito larvae, the efficacy of which was 

 demonstrated in 1914. Since that time it has been widely distributed 

 and has rapidly midtiplied. 



Dickinson (C. G.). Report of the Chief Veterinary OfiBcer. — Northern 

 Territory Australia Rept. Administrator for Years 1915-16 and 

 1916-17, Darwin, 10th January 1918, pp. 42-43. [Received 

 15th January 1919.] 



Bulialo flies {Lyperosia exigua), which are a great pest of horses 

 and cattle during the wet season, can be effectively controlled by the 

 use of Japanese fish-oil, which experimentally renders cattle immune 

 for a period of from 4 to 6 days, though in the bush the protection 

 afforded cannot be relied on for more than 1 to 3 days. 



At one station the stock was found to be tick-infested though not 

 with the true cattle tick, Boophilus, but as far as could be determined 

 fi-om defective specimens, with a species of Haemaphysalis or 

 Amhlyomna. 



% 

 HowLETT (F. M.). Report of the Imperial Pathological Entomologist- 



— Scient. Repts. Agric. Research Inst., Pusa, 1917-18 ; Calcutta, 

 1918, pp. 117-120. [Received 21st January 1919.] 



Attention was chiefly directed during the year to the comparative 

 study of the habits of Tabanid larvae, and to working out the life- 

 histories of certain midges at Pusa belonging to the genera Culicoides 

 and Ceratopogon, a group of which very little is known ; investigations 

 are being continued in view of the possibility that these flies may 

 convey disease. 



Investigations on the trap-breeding of Stegotnyia, i.e., the supply 

 of artificial breeding-places, have been continued, and a number of 

 organic compoimds have been tested as larvicides, without any 

 practical results except in the case of xanthates, which have a very 

 high toxicity for mosquito larvae. Experiments to ascertain the 

 factors which influence mosquitos, especially Stegomyia albopicta 

 (scutellaris), in their choice of breeding- places have shown that tempera- 

 ture has a definite influence, eggs bemg laid more freely in warm 

 water ; various chemical compounds have a deterrent effect when 

 dissolved in small quantities (| to 1 per cent.) in the water ; a few 

 substances, especially sodium citrate and tartrate, have an attractive 

 effect, a far larger number of eggs being laid in dilute solutions of these 

 substances than in pure water. Work is being carried on with the 

 object of discovering a repellent, limited as regards cost, which shall 

 effectively prevent Tabanids from attacking camels, and so help to 

 check the spread of surra among transport and other animals. 



