27 



1,435 gram rabbit in 3]; minutes. So far as can be determined, the 

 insects contain a nenro-toxin, which has a direct effect upon the 

 action of the heart of both chickens and rabbits and is excessively 

 dangerous as a food for chickens. It is essential that chickens be kept 

 in mowed fields and away from grape vines and shrubs upon which 

 the rose chafers may be abundant. 



Theiler (Sir A.). The Problem of Horse-Sickness. — South African Jl. 

 Sci., Cape Town, xii. no. 3. October 191-3, pp. 65-82. [Received 

 29th December 1915.] 



Facts collected up to the present time tend to show that horse- 

 sickness is transmitted by winged insects and experience has shown 

 that the exclusion of such insects from stables prevents infection, 

 though attempts to transmit the disease with various insects have failed. 

 The negative results obtained are attributed to the difficulty of keeping 

 winged insects alive in an insect-proof loose-box together with a horse 

 for a sufficiently long time, or even in a glass cylinder when feeding 

 them individually. In experiments undertaken to find out the source 

 of infection of the insect host, the results were negative, but it was 

 ■observed that other domestic animals are probably also susceptible 

 to this disease. Horse-sickness occurs throughout Central and East 

 Africa to the Red Sea. The question of immunity is discussed, as 

 well as prevention of the disease by protecting the animals from 

 infection. 



Poison Bait for Biting Flies. — South African Jl. Sci., Cape Town, xii, 

 no. 3, October 1915, p. 94. [Received 29th December 1915.] 



It has been found possible to destroy Stomoxys calcitrans by means 

 of a liquid poisoned bait, containing 1 per cent, of sodium arsenite 

 and 10 per cent, of sugar. The possibility of destroying other biting 

 flies in South Africa, such as tsetse-flies and Tabaxidae, in the same 

 way, is suggested. 



Macfie (J. W. S.). Observations on the Bionomics of Stegomyia 

 fasciata. — Bull. Entom. Research. London, vi, no. 3, December 

 1915, pp. 205-229, 2 tables. 



In investigating the habits of Stegomyia fasciata only recently 

 emerged adults were used. They were kept in glass jars with water 

 at the bottom. A fold of paper was fixed in the middle of the jar for 

 the insects to rest on. and on the upper surface of the paper drops of 

 honey were placed. Human blood was supplied daily. The maximum 

 length of life of the males was 28 da vs. and that of the females. 62 da vs. 

 Several females showed signs of senescence after laying a number of 

 batches of eggs. The first blood-meal taken by the female was on 

 the second or third day after emergence from the pupa. Fertilisation 

 and a blood-meal preceded oviposition, and fertilisation preceded the 

 blood-meal. Eggs were laid on the sixth or seventh day. After this, 

 they fed regularlv once, soon after each batch of esfcrs was laid. Three 

 or four days elapsed between each act of oviposition. Egg-laying 

 continued throughout life, the number in each batch varying greatly. 



