451 



according to the development of the host, the growth being slow 

 when the host is hibernating. When solitary, Tachinid larvae are 

 able to Hve equally well in small hosts as in large ones. The nmnber of 

 individuals occurring in the same host depends on the size of the host, 

 e.g., ten Viviania cinerea may occur in Procrustes coriacem, and only 

 one in Pterostichus niger ; but this is only seldom decided by the parent, 

 and Winihemia will deposit up to 100 eggs on one Sphingid larva. 



The number of generations a year in Denmark is one or two, possibly 

 more in certain cases, the number being always constant in a given 

 species. Some species exhibit the same number everywhere within 

 their geographical range, but others have more in the south than the 

 north ; thus Tachinafasciata has one generation in Greenland, and two 

 in Denmark. In an Indian species there are 8 or 9 generations a year. 

 The number of generations does not always conform to that of the host, 

 e.g., Pelatachina tibialis infesting larvae of Vanessa has only one 

 generation a year, and the majority of Tachinids that have more than 

 one generation will live in hosts having only one, and thus must 

 change their host. Certain species having two generations however do 

 infest hosts having the same number, and do not change their hosts 

 e.g., Meigenia floralis infesting Gastroidea (Gastrophysa) viridula. 



Tachinids that have one generation emerge in the spring ; their 

 larval stage is very short, and they spend ten months in the puparimn. 

 Viviania cinerea, however, hibernates as a second-stage larva. 

 Tachinids having more than one generation may be met with through 

 the whole summer, and individuals belonging to different generations 

 occur at the same time. 



Most of them hibernate as a puparium, but Subclytia rotundiventris 

 hibernates as a second-stage larva. 



Nielsen (J. C). Undersogelser over entoparasitiske Muscidelarver 

 hos Arthropoder VII. [Researches on endoparasitic IMuscid 

 Larvae in Arthropods]. — Videnskabelige Meddel., Coj^enhagen, 

 Ixx, 1919, pp. 1-3. 



The Tachinid, Plagia ruralis, Fin., has been reared from the cater- 

 pillars of Phytometra (Plusia) gamma, L., and P. iota, L. j ^ j 



Bahk (L.). Paratyfus hos Honningbien [Paratyphus in Honey Bees]. 

 — Skandinavisk Veterindr-Tidsskrift, ix, 1919, pp. 25-40, 45-60. 



An acute enteritis of bees in the vicinity of Copenhagen has been 

 found to be due to Bacillus paratyphi-alvei, the bees showing symptQpis 

 of debility, inability to fly and sometimes diarrhoea, and dying in from 

 24 hours to a few days. The disease was introduced with purchased 

 infected bees, and in eight bee-hives 50 per cent, of the bees 

 succumbed in a fortnight. Bacillus paratyphi-alvei was found in 

 great numbers in the gut of all the infected bees, often almost as a 

 pure culture, and was also found in the blood. It is not identical 

 with the forms of B. imratyphi found in man and domestic animals. 



The feeding of healthy bees and of Vespa with pure cultures dissolved 

 in 5 per cent, sugar solution showed positive results, but mice, guinea- 

 pigs and rats were not susceptible. While the organism is not normally 



