1909.] Summary of Agricultural Experiments. 319 



probably been brought about, not by greater care in the selection of 

 starters, but by making a mild-flavoured butter from pasteurised 

 cream ripened to a low degree of acidity. The presence of O'idium 

 lactis in Australian butter may be considered, not as the cause of 

 fishiness, but merely as an indication that the butter was made from 

 high-acid cream, a condition which is well known to favour the growth 

 of this organism. 



In considering the practical application of these investigations, it 

 may be said that the butter maker who receives whole milk or fresh 

 sweet cream can prevent the appearance of this trouble with certainty. 

 High-grade butter with a low acidity may be made by adding a good 

 starter to pasteurised cream and churning without ripening, or the 

 pasteurised cream may be churned sweet without the addition of any 

 starter. In creameries receiving hand-separator cream in which the 

 acid is well developed, the problem is more difficult, and under such 

 conditions it may be impossible to prevent fishy flavour. The amount 

 of working, however, which the butter receives is almost entirely under 

 the control of the butter maker, and overworking should be avoided. 



Destruction of Red Spider by Spraying (Journal of Economic Ento- 

 mology, Concord, N.H., Vol. L, No. 6, December, 1908). The damage 

 done by red spiders in Great Britain is very extensive (Leaflet No. 41), 

 and any method which is likely to prove effective in controlling their 

 multiplication and spread is of interest to the horticulturist. In the 

 Journal of Economic Entomology Mr. H. M. Russell, of the Bureau 

 of Entomology, Washington, gives a short account of experiments 

 conducted in Florida with a view to control the red spider Tetranychus 

 bimaculatus, Harv. The spring of 1908 being very dry for some weeks, 

 with little rainfall, injury by red spider was very noticeable. The 

 experiments were conducted in a small field of wax beans which were 

 very badly infested. 



On May 22nd a row was sprayed with lime-sulphur at the rate of 

 1 lb. lime and 1 lb. sulphur to 25 gallons of water, the lime and sulphur 

 being boiled together in a portion of the water. A comparison with 

 unsprayed plants on May 28th showed that 76 per cent, of the red 

 spiders had been killed by the one spraying. The plants were uninjured 

 by the spray. 



On May 28th a row of the beans was sprayed with lye-sulphur (1 lb. 

 sulphur and \ lb. lye in 40 gallons of water), and on May 30th com- 

 parison with unsprayed plants showed that no less than 98*4 per cent, 

 of the red spiders had been killed, the plants being uninjured. 



In another case a row was sprayed with sulphur in water (1 oz. to 

 1 gallon of water), and it was found that 91*7 per cent, of the red 

 spiders had been destroyed. 



Kerosene-soap emulsion was also tried, and an examination the 

 following day showed that 95 per cent, of the red spiders were killed. 

 The plants showed a few leaves with burned edges, but this was not 

 serious. 



In all cases the beans were sprayed below as well as above. 



Observation was also made as to the effect of rain on the red spiders, 

 and it was observed that heavy rain for one day only did not seriously 

 affect the pests, but continuous rain for several days appeared to be fatal 

 to a large proportion of them. 



