56 



in early August were found to have already hatched. The appearance of 

 G. haemorrhoidalis is probably contemporaneous with that of G. rMsalis. 

 G. intestinalis appears somewhat later and continues active far into 

 the autumn. Of the three species, G. intestinalis causes less appre- 

 hension to the animal than the other two. Farmers in western 

 Canada frequently shield the hps of their horses from G. haemorrhoidalis 

 by means of a wire-screen muzzle of close mesh. As an improvement 

 upon this, an apparatus has been devised consisting of a leather band 

 cut into a series of narrow strips long enough to cover the lips of the 

 horse. The band is buckled under the chin and could also be attached 

 to the head- stall. As a further protection to the nose when the 

 animal raises its head an extra leather flap should be attached to the 

 band dij:ectly over the nose and also cut into strips on the lower 

 margin. As a preventive against G. nasalis, a piece of canvas extend- 

 ing from the nose-band to the throat is attached under the jaws, 

 and can be fastened to the ring of the head- stall on each side by a cord. 



Lodge (0. C). An Examination of i^the Sense-Reactions of Flies. — 



Bull. Entom. Research, London, ix, no. 2, September 1918, 

 pp. 141-151, 4 plates. 



Experiments with various flies, and particularly those concerned 

 in the transmission of intestinal diseases, have been carried out with 

 a view to determining their Ukes and dishkes and their response to 

 stimuli afiecting the senses of smell, sight, touch, taste and the 

 perception of the differences of temperature and humidity. The species 

 tested included Musca domestica (house-fly), Fannia canictdaris 

 (lesser-house-fly), F. scalaris (latrine fly), Calliphora erythrocephala 

 (blue-bottle), C. vomitoria (blue-bottle), Lucilia caesar (green-bottle) 

 and Phormia azurea {groenlajidica). A table shows that the percentages 

 of the sexes coming to various baits is approximately equal. The 

 results of offering various baits to different species of flies are also 

 given in tabulated form. A general similarity of taste was observed 

 between the different species with regard to various chemicals and 

 foods ; the tastes of M. domestica and P. azurea were found to approxi- 

 mate most nearly. The experiments demonstrated extreme curiosity 

 on the part of house-flies and also showed the difficulty of finding 

 any substances that will either attract or repel all those that come 

 near them. Mineral and tar oils seem to be among the most repellent 

 substances, and no flies came near the baits to which a few drops 

 of these oils had been added. This distastefulness frequently dis- 

 appeared, however, after the preparation had been left exposed for 

 a number of hours. The oils of cloves, geraniol, cummin, sassafras 

 and cinnamon bark were found to be the most repellent to house-flies. 



As regards poisons, good results were obtained with sodium iodate ; 

 when small quantities were mixed with the baits the flies feeding upon 

 these died very quickly, in some cases 99 per cent, were dead in 

 21 hours. The results from this poison are given in a table and are 

 contrasted with those obtained from formaldehyde solutions, the 

 former accounting for many more deaths than the latter. Sodium 

 iodate has the disadvantage of being very expensive, but further 

 experiments are desirable before definite conclusions can be reached 

 regarding the importance of the iodates of sodium and other metals 



