177 /.V^'»«"- 



Paillot (A.). Deux Microsporidies nouvelles, Parasites des CJbentlles (Ig ^^ 



Pier is hrassicae. [Two new Microsporidian Parasites of th«7'^' ^J 

 Larvae of Pieris hrassicae.] — C.R. Soc. Biol., Paris,^xxi, no. 2, "^J, 



26th January 1918, pp. 66-68, 1 fig. " <^''?/ Um^'^''^.'^-^' 



During the occurrence of a severe infestation of Pieris brasstcde'm 

 the neighbourhood of Lyons in 1917, the author has had ample oppor- 

 tunity of studying the parasitisation of these larvae, and has discovered 

 two new parasitic microsporidia, one of which, Perezia mesnili, sp. n., 

 forms the subject of the present note. The other will be described 

 in a later paper. 



LizER (C.). Un Coccido nuevo para la Republica Argentina : Saissetia 

 hemispha erica, Targ. [A Coccid new to the Argentine RepubHc : 

 Saissetia hemisphaerica, Targ. J — Physis, Buenos Aires, ii, no. 12, 

 30th December 1916, pp. 422-423. 



Saissetia hemisphaerica, Targ., has now extended its distribution 

 into the neighbourhood of Buenos Aires, where it has been found on 

 ferns. 



Barbae! (B.). Estado actual de los Estudios sobre el Coccohacillm 

 acridiorum, d'H6relle. [The Present Situation of Investigations 

 regarding Cocccohacillns acridiorum, d'Herelle.]. — Rev. Instit. 

 Bacteriohgico, Buenos Aires, i, no. 1, November 1917, pp. 107-113. 

 [Received 26th February 1918.] 



This paper reviews the experimental work that has been undertaken 

 with the object of determining the possible value of d'Herelle's Cocco- 

 baciUus acridiorum in the destruction of locust swarms. From the 

 results arrived at, the conclusions are^awn : ( 1 ) That the Coccohacillus 

 considered by d'Herelle as the cause of the epizootic in Yucatan in 

 1909 is innocuous to the locust after passing a certain length of time 

 in culture media. (2) The organism can however be rendered more 

 \nrulent by its passage through locusts, until it is capable of kilhng 

 these by injection in 4 or 6 hours. (3) This virulence is rapidly lost 

 when the organism is exposed to an exterior medium. (4) This viru- 

 lence, according to the Argentine Commission, is not sufficient to destroy 

 locusts even when the culture is ingested by them in enormous quan- 

 tities ; even at its best the Coccohacillus destroyed only 40 per cent, 

 in these circumstances. 



Natural epizootics are known to occur among locusts and to cause 

 a definite degree of mortality, which is very difficult to estimate when 

 the disease has been artificially increased. In locusts that have 

 contracted this natural infection, and even in those that show no sign 

 of disease, organisms identical in morphology and bionomics with 

 C. acridiorum have been observed, and these can be brought to an 

 equal degree of virulence in the same manner. 



There are still many points remaining to be elucidated. It is still 

 disputed whether the Coccohacilhis isolated from dead locusts is the 

 principal cause of the spontaneous epizootics observed by d'Herelle 

 in Yucatan and by other investigators elsewhere. These epizootics 

 show greater severity of infection and rapidity of dissemination than 

 can be produced artificially. The possibility of killing in the laboratory 



(C463) Wt.P2/137: 1.500. 5.18. B.&F.Ltd. Gp.11/3. a 



