492 



MTSS O. C. LODGE ON THE 



casein, banana, and brown sugar ; or casein, banana, and golden 

 syrup; or casein and brejid — all of which weie mixed with 

 sufficient Avater to make into a paste. These mixtures, more- 

 over, generally required a day or two in which to ripen before 

 reaching their most attractive stage, which then lasted for a 

 considerable time. 



They were tested, amongst others, against the well-known 

 reci2")e of beer and sugar, which was found to be immediately 

 attractive, though it did not remain so for any length of time, 

 only about two or three days. It was subsequently seen that the 

 addition of beer, or preferably stout, to the casein, sugar, and 

 banana mixtures, or to casein alone, made them immediately 

 attractive, and that, when the effect of the beer or stout had 

 gone off, the casein mixtures were themselves attractive and 

 remained so for many days. 



Several of these casein mixtures were also tested in the kitchen, 

 but only a certain number of the flies were caught. This was 

 probably due to the various counter-attractions present, though 

 on one occasion * twenty house-flies were caught between 5 p.m. 

 and 10 A.M. the next morning. This number was well over half 

 the flies in the kitchen, though on other occasions fewer were 

 generally caught. Yet these baits, even in the greenhouse, where 

 as many as 600 have been caught in 6-7 hours, never by 

 any means caught all the flies, but only a proportion of them. 

 Other methods are likely to be found more effective in ridding 

 kitchens of flies than the use of baited traps, e. g. spraying or fly- 

 papers. 



Other casein baits were also placed in difterent parts of the 

 garden, as well as b}^ the dust-bin, when various flies were caught, 

 including Mtcsca, Calliphora, Lucilia, Fannia, a few Sarcopliaga 

 and many i?or6orMs ; though more blow-flies were always caught 

 with meat baits. 



A summary of the results obtained from the experiments on 

 House-fly Baits is given below (J-0). The substances are 

 classified according to their attractiveness. 



(N.B. — The days only are given on which the largest 

 number of flies were caught. In most cases 

 fewer flies were caught on the other days as well.) 



(J) S'uhstances fotmd to be the most attractive to House-flies. 



Days on ivltich most flies were cavght 

 Saits. (i.e. approximately 90-100 or more 



flies at each of the counts). 



Casein -I- golden sj'rup + bread + water 9-10 



„ + brown sugar -I- water 3-8 



„ -I- bread + water 3-6 



„ -(-brown sugar -f- dried blood -1- water 3-6 



" + J) ;> + » „ + „ -I- maggots . 1-4 



* The bait consisted of casein -I- brown sugar -I- beer (3 daj's old). 



