IN'JURIOUS VERTEBRATES 1391 



IXjrRIOUS VERTEBRATES. 

 1056 - The Control of Field Voles in Italy. — Splen-dore alfoxso, in Rcndiconti ddic scdutc 



delta Rcale Accademia dci Lined, Classc di Scienze fisiche, matematiche e naturali, Series 5, 

 Vol. XXV, 2nd Half Year, Part I, pp. 46-49. Rome, Juh' 1916. 



In Capitanata (province of Foggia) and the adjoining provinces (i) 

 which have been invaded by field voles, the Italian Government has inter 

 alia appointed a Committee instructed to take such measures as mav 

 be best adapted to combat this scourge. 



Technical experts have been sent to the region over-run, both in order 

 to study the effects on the spot and to undertake control measures by all 

 possible means. Ditches have been excavated and traps used to prevent 

 or at any rate limit the spread of the field voles from the fields to the vine- 

 3'ards. Different poisoned baits have been put down, and different kinds 

 of virus have also been used. 



The ditches and traps proved eft'ective, but insufficient to achieve the 

 purpose in view of the extent of the infested parts and the considerable 

 number of the rodents. 



Among the poison used, zinc phosphide alone proved efficacious (2). 



The dift'erent viruses gave negative results undoubtedly owing to loss 

 of their virulence. 



It is well known that the viruses which have been recognised as suita- 

 ble for field vole control are Loffler's bacillus and Danysz's bacillus (3). They 

 ma}- be transmitted to field voles either bj* subcutaneous injections 

 or through the digestive passages, but the drawback is that the cultures 

 easily lose their virulence. The Ministry of Agriculture therefore instructed 

 the writer to undertake investigations with the object of producing a new 

 virus of sufficient acti^'ity for the case in question ; the investigations were 

 carried out partly in Capitanata and parth' in the Laboratory of Agric- 

 ultural Entomology of the Royal University of Rome. 



In field voles {Pytymys savii) captured at Cerignola, the writer obser\-ed 

 the constant presence of a micrococcus, both in the circulating blood and 

 in the various internal organs, and the lymphatic glands in dift'erent parts 

 of the body. In some of these rodents, for which a microscopic examination 

 of the internal organs had given negative or almost negative results, the germ 

 was found in large quantities in the lymphatic glands of the axillae. The 

 micro-organism is readily stained with aniline dye and Gram's stain. In the 

 tissues, where it occurs both within and without the cells, it often has the coc- 

 ciform and even diplococcal appearance ; in artificial cultures (agar and ord- 

 inary- bouillon) it retains this appearance for some time ; later on, it takes 

 on a more and more bacillary aspect, and occurs likewise in short and thick- 



(i) See B. August 1916, No. 921. (Ed.) 



(2) See B. Januar\' 1914, No. 89, 



(3) See B. Tan. 1911, No. 362; B. June 1911, No. 2016 ; B. Oct. 1012, No. 1488 ; B. Nov. 

 1912, N. 1567 ; B. July 1913, No. 897 ; B. Jan. 1915, No. 132. (Ed.) 



