XIX] STOMOXYS AND DISEASE 361 



districts, where the removal of manure is impracticable, the 

 manure heaps should be sprayed periodically with some insec- 

 ticide, in order to destroy any eggs, or larvse, that may be 

 present. 



REFERENCES. 



Austen (1909). African Blood-sucking Flies. London : Brit. Mus 

 Bouffard, G. (1907). Compt. Rend. Sac. Biol. vol. lxii. p. 71. 

 Newstead, R. (1907). Ann. Trop. Med. and Parasit. vol. 1. p. 76. 

 Tulloch (1906). Proc. Roy. Soc. vol. lxxvii. B. p. 523. 



CHAPTER XX 



INFECTIONS TRANSMITTED BY STOMOXYS 



I. Trypanosomiases. 



There is no doubt that under experimental conditions the 

 direct transmission of various trypanosomiases from infected to 

 healthy animals, is comparatively easily effected by means of 

 the bites of Sfonioxys, but with regard to the importance of 

 this insect in the spread of disease, opinion is still very divided. 

 Surra {T. evansi) is generally stated to be transmitted by 

 Stomoxys as well as Tabanus, and yet Mitzmain in the Philip- 

 pines made a most exhaustive series of experiments on the 

 transmission of this disease by Stomoxys calcitrans and obtained 

 uniformly negative results. In Africa, Bruce, Grieg and Gray, 

 Bevan, and others have also been unsuccessful in attempts to 

 transmit various trypanosomiases by this insect. Nevertheless 

 a number of observers are of the opinion that Stomoxys plays 

 an important part in the transmission of certain infections. 

 Thus in Java, according to Schat, Surra is mainly spread by 

 the agenc}'^ of Stomoxys calcitrans Linn, and Lyperosia exigua 

 de Meijere, but experimental proof is lacking. Similarly, 

 Musgrave and Clegg stated that in the Philippines it has been 

 *' conclusively shewn that Stomoxys calcitrans B.nd other biting 

 flies transmit the disease," but this statement is somewhat 

 exaggerated. 



