100 



punctures and sucks up blood through the proboscis alone while on 

 the wing ; or the insect alights and punctures with its proboscis ; or 

 the insect aUghts, punctures with its other trophi, and then sucks up 

 blood through its proboscis. 



From a consideration of the structure of the mouth-parts, it must 

 be concluded that the male could only suck blood which was flowing 

 from a wound already present on an animal, such as might be caused 

 by the bite of a female Tabanid. This is merely a possibility, but not 

 a probability, since there is no authentic record of a male feeding 

 except on the nectar of flowers. The female can likewise feed in this 

 way, but also sucks blood, probably by the last of the methods enu- 

 merated above. It is possible that certain species feed only while 

 hovering, and others only when settled, but further investigations are 

 needed on this point. It is improbable that a puncture is ever effected 

 by the proboscis itself, since in the living insect the apex is flexible, 

 and has not the rigidity usually associated with piercing organs. 



Davidson (Capt. J.). Some Practical Methods adopted for the Control 

 of Flies in the Egyptian Campaign. ^ — Bull. Entom. Research, 

 London, viii, no. 3-4, February 1918, pp. 297-309, 7 figs. 



Flies are present in Egypt practically all the year round, though 

 they are less numerous during the height of the hot weather and again 

 about December. Since they are the means of spreading diarrhoea, 

 dysentery, typhoid and cholera, it is of the utmost importance that 

 they should be vigorously suppressed. Flies of the house-fly type 

 {Musca) are the most troublesome, although bluebottles {Calliphora), 

 greenbottles {Lucilia) and Sarcojyhaga are found, these last being 

 often met with in the desert in small clumps of palm trees. 



During 1916-17 the work of the sanitary section consisted in the 

 special treatment of breeding places and the destruction of flies by 

 spraying, poisoned bait, traps, etc. The three favourite breeding 

 places for flies of the house-fly type are (1) horse manure, (2) accu- 

 mulation of camp and cook-house refuse, (3) latrine trenches ; those 

 of the bluebottle type prefer putrefying animul matter. 



The disposal of horse manure was effected in three ways : by close 

 packing and spraying, by incineration, and by spreading it to make 

 manure roads. The first of these is specially suited to a large camp, 

 a site about 2,000 yards away from the camp being selected and staked 

 out in two areas, 25 yards long and 10 yards wide, separated by 

 a strip 2 yards wide. All horse manure and burnt refuse from inciner- 

 ators was deposited daily on this site, the areas being used alternately, 

 and the load being immediately raked level. In the late afternoon 

 this surface was thoroughly drenched with a rough emulsion made 

 of crude tar oil, or green oil when available, mixed with water in an 

 adjacent 300-gallon tank, and applied by means of watering cans at 

 the rate of 1 gal. per square yard. It was then covered with large 

 pieces of sacking sewn together, though this was later discontinued 

 as being unnecessary. A number of empty oil-drums were placed 

 upside down round the heaps, the bottoms, which were made concave 

 like saucers, being filled every morning with a solution of 1 per cent, 

 sodium arsenite in water containing 12 per cent, glycerine and 5 per 

 cent, sugar. Flies were killed in such enormous numbers by this means 

 that at the end of a few days hardly any remained, the treatment 



