62 



order with which the Siphonoptera have affinities. Infection of the 

 ahmentary canal at the larval period has been shown to persist to 

 the adult stage in the case of the house-fly {Mvsca domestica), Calli- 

 'phora erythrocejphala and a species of Sarcophaga. 



Bacot (A. W.). The Effect of the Vapours of various Insecticides upon 

 Fleas {Ceratophyllus faseiatus and Xenopsylla cheopis) at each 

 Stage in their Life-History and upon the Bed-Bug [Ciinex leclu- 

 larius) in its Larval Stage. — Jl. Hygiene, Cambridge, Plague 

 Svp'pleinent III. 14th Jan. 1914, pp. 665-681, 1 fig. 



The author carried out a series of experiments in order to test the 

 relative efficiency of various insecticides and disinfecting fluids, and 

 the effectiveness of the vapour under conditions permitting free 

 access of air. In the experiment a small tin box without its lid was 

 placed at the bottom of the jar to contain the insecticide, and the fleas 

 in their various stages were placed in boxes fastened about two inches 

 above the insecticide. The insecticides used were solutions of pure 

 phenol, lysol and formalin, commercial benzine and paraffin oil, flake 

 naphthalin and crushed camphor. The fleas experimented with 

 were Xenopsylla cheopis and Ceratop)hyllus faseiatus; a few experiments 

 were also made with the bed-bug, Cimex lectularius. Details of the 

 experiments are given and also tabulated summaries of the results. 

 Naphthalin was found to be the most generally effective agent in killing 

 fleas in all stages, and dissolved in benzine could be poured into cracks 

 and crevices. For use in rat-holes, especially in foundations, a soap- 

 carbolic or soap-petroleum emulsion (duly watered down) might be 

 used with the addition of flake naphthalin. Adult fleas or bugs are 

 best treated with some liquid insecticide, and whether crude phenol 

 or petroleum be the basis of the insecticide, it should be always made 

 into an emulsion with soap, so that contact with the insect may be 

 secured. The vapours of both phenol and lysol solutions are also 

 efficacious, aft'ecting the intestinal tract. Benzine is uncertain as 

 a vapour, some fleas recovering after the benzine has evaporated. 

 A few experiments were made for the purpose of testing the effect of 

 a strongly smelling ointment in preventing fleas and bugs from biting. 

 A saturated solution of naphthalin in benzine was added to melted 

 vasehne. The ointment killed a number of Pulex irritans, and a number 

 of second instar Cimex lectularius did not feed, but were not otherwise 

 affected. The death of the fleas was j^robably due to the benzine 

 vapours. Subsequent tests showed that the ointment was onl\- a 

 partial protection against the bugs. 



Bacot (A. W.). A study of the Bionomics of the common Rat Fleas 

 and other Species associated with Human Habitations, with special 

 reference to the influence of Temperature and Humidity at various 

 periods of the Life-History of the Insect. — Jl. Hygiene, Cambridge, 

 Plague Supplement III, 14th Jan. 1914, pp. 447-654, 8 pis., 

 12 charts, 3 figs. 



In this paper Mr. Bacot reports an extensive and elaborate investi- 

 gation of the effect of external conditions on the development of the 

 eggs, larvae, pupae and adults of various fleas, viz., Ceratophyllus 



