202 



is not transmitted between 7 a.m. and 5.30 p.m. ; but Seidelin and 

 Connal in 1914, and Macfie in 1915, showed that S. fasciata, when in 

 captivity, bites at any hour irrespective of age. 



In the experiments here described, the conclusions reached were 

 that, under natural conditions, S. fasciata will bite either by day or 

 night, for 14 days after the first blood meal. 



Kewstead (R.) & Evans (A. M.). Report on Rat-flea Investigation.— 

 Ann. Trop. Med. & •Parasit., Liverpool, xv, no. 3, 30th September 

 1921, pp. 287-300, 7 tables, 4 charts. 



The investigations here described were undertaken to determine 

 the distribution of fleas occurring on rats in the Port and City of 

 Liverpool, with special reference to those species responsible for 

 transmitting plague. Tables show the number of rats taken on ships 

 and the ports they came from, the distribution of the rats, Mas rattus 

 and M. norvegicits, and of the fleas, of which five species occurred, 

 namely : XenopsyUa cheopis, Rothsch., Lcptopsylla musculi, Duges, 

 Ccratophylliis fasciatiis, Bosc, C. londoniensis, Rothsch., and Cteno- 

 ccphaliis canis, Curtis. The first named occurred freely on rats in 

 ships, and was found on rats from dock sheds ; isolated specimens 

 were also taken from warehouses and in the city. A permanent 

 breeding place was discovered in certain premises in the warehouse 

 zone. Ceratophylliis fasciatiis was universally prevalent. The number 

 of fleas per rat was greatest during the summer months, but the curve 

 of frequency could not be correlated in detail with that of the average 

 temperature. Ceratophylliis londoniensis was found rarely in the 

 city and docks. L. mnscidi seldom occurred on ship rats and was 

 most prevalent on rats from the docks. One individual of Cteno- 

 cephaliis canis was taken in the city. Ctenoplithalmits agyrtes, Heller, 

 was not found. 



Young (C. J.). Natural Enemies oJ Stegomyia calopus, Meigen. — 

 Ann. Trop. Med. & Parasit., Liverpool, xv, no. 3, 30th September 

 1921, pp. 301-313, 2 figs., 2 plates. 



The absence of larvae of Stegomyia fasciata (calopus) from many 

 suitable breeding places in Brazil, attracted attention during their 

 collection in Manaos. They proved capable of developing in such 

 places except where aquatic insects were present, and experiments 

 proved that the larvae are destroyed in varying degrees by the larvae 

 of dragonflies, water beetles and various Rhynchota. The mosquito 

 larvae most commonly found were those of S. fasciata and Culex 

 fatigans. The latter are less liable to attack by predaceous enemies, 

 as they are more active and can remain stationary at the surface for 

 long periods. 



Experiments were carried out with the larvae of dragonflies 

 (Aeschnidae and Libellulidae) and water bugs [Zaitha spp.). The 

 former larvae were found all the year and can live in comparatively foul 

 water. One species used experimentally, Pantala flavescens, destroys 

 larvae and pupae of S. fasciata of all sizes. The water bugs were 

 less common. They feed on aquatic insects and others, such as grass- 

 hoppers, that fall into the water. The results show that dragonfly 

 larvae alone are most eft'ective against S. fasciata, and a combination 

 of water bugs and dragonfly larvae against C. fatigans. In experi- 

 ments under natural conditions, two barrels containing larvae of 



