161 



Leproy (H. M.). Fly Sprays.— r^f/fs. Son. Trop. Med. & Hyg., 

 London, xiii, no. 1, IGth May 1919, pp. 1-9. [Received 18th 

 August 1919.] 



Extensive work carried out witli numerous substances as sprays 

 for flies is described and details of the results are given. 



The following formula proved to be the most efficacious : 2 lb. 

 pyrethrum, 1 gal. spirit, 1 gal. safrol and enough soap to make the 

 mixture emulsify (about 10 oz.). This mixture should be diluted 

 at 1 to 30. Although sprays have proved of great value hi hospitals 

 and private houses, they are of no use in the open, where the only 

 possible means of fly control is the prevention of breeding. 



The above formula failed completely when used in hot climates, 

 but proved effective with the addition of |^ to 2 per cent, of castor oil. 



O'Connor (F. W.). An Outbreak of Itch due to a predaceous Mite, 

 occurring in England amongst Men engaged in unloading Cotton 

 Seed from Egypt. — Trans. Soc. Trop. Med. & Hyg., London, xiii, 

 no. 1. 16th May 1919, pp. 10-13, 2 figs. 



This outbreak of the mite, Pedicidoides ventricosus, in 1913 at the 

 London docks, has already been recorded [see this Review, Ser. B, 

 ii, p. 163]. The irritation caused in man is probably due to the 

 bite of the mite and its numerous bristle-like hairs, as no individuals 

 were noticed burrowmg either in the cases presented for examination 

 or in the experimental ones. The mite is described. Similar infections 

 may arise from sleeping on newly made straw mattresses. 



MuNRO (J. W.). Report of Scabies Investigation.— J?. R.A.M.C., 



Ljondon, xxxiii, no. 1, July 1919, pp. 1-11, 6 figs. 



The observations and experiments detailed in this report deal 

 chiefly with Sarcoptes scabiei var. hominis, Megn., which is the variety 

 that most usually infests man, although attacks by var. equi, Megn., 

 var. capreae, Megn., var. cameli, Megn., var. suis, Megn., var. cmiis, 

 Raill., var. cameli, Raill., and var. leonis, Raill., have been reported 

 at different times. 



The variety of mite infesting man is described and its relation 

 to disease is reviewed. Patients suffering from scabies seem especially 

 susceptible to inoculation with trench fever, owing to the continual 

 scratching that it gives rise to. The egg-stage lasts about 2J to 

 3| days, the larval 1|- to 3, the 1st nymphal 1|^ to 2|, and the 2nd, 

 2 to 4. The adults may live 3 to 5 weeks. The eggs, between 40 

 and 50 in number, are deposited in the burrows made by the female 

 in the epidermis of the host. The larvae on hatching bury them- 

 selves in the floor of the original burrow and give rise to vesicles. 



Particulars of the first nymphal stage are not known, but the second 

 is found in burrows smaller than those of the adult female and 

 unaccompanied by vesicles. Small pockets may be found alongside 

 of these burrows which frequently contain a male Acarid. It is 

 beUeved that pairing takes place during this stage. 



The mite may be conveyed from one individual to another by body 

 contact, blankets or clothing. The clothing of infested persons may 

 remain infective for at least fourteen days. 



