ENTOMOLOGY 377 



treatment if necessary in January and February, the latter just 

 before the flower spurs start, results in no injury. 



How to Use the Emulsions. During the growing period of 

 summer, for most aphides and other soft-bodied insects, dilute the 

 emulsion with 15 carts of water; for the red spider and other plant- 

 mites, the same, with the addition of 1 ounce of flowers of sulphur 

 to the gallon; for scale insects, the larger plant-bugs, larvae, and 

 beetles, dilute with from 7 to 10 parts of water. Apply with spray 

 pump. The greatest dilution noted gives 4 per cent of oil and the 

 lesser dilutions approximately 6 and 8 per cent. 



For winter applications to the trunks and limbs of trees in the 

 dormant and leafless condition to destroy scale insects, stronger mix- 

 tures may be used, even to the pure emulsion, which can not be 

 sprayed successfully but may be applied with brush or sponge. Di- 

 luted with one or more parts of water it may be applied in spray with- 

 out difficulty. The use of the pure emulsion is heroic treatment and 

 only advisable in cases of excessive infestation. 



The winter strengths recommended are the emulsion diluted 

 with either 3, 4, or 5 parts of water, giving approximately 17, 13, 

 and 11 per cent of oil. These dilutions are equivalent in strength 

 to oil-water sprays containing 25, 20, and 15 per cent of oil, because 

 relatively more of the emulsion is held by the bark. The two 

 stronger mixtures may be used on the apple and pear and the 

 weaker one on peach and plum. The winter treatment may be fol- 

 lowed in June by a use of the summer wash to destroy any young 

 which may come from female scales escaping the stronger mixture. 



Cautions Regarding Use of Oil Washes. In the use of kerosene 

 washes, and, in fact, of all oily washes on plants, the application 

 should be just sufficient to wet the plant without allowing the liquid 

 to run down the trunk and collect about the root. Usually, in the 

 case of young trees at least, there is a cavity formed by the swaying 

 of the tree in the wind, and accumulation of the insecticide at this 

 point, unless precautions be taken, may result in the death or injury 

 of the plant. Under these conditions it may be advisable to mound 

 up the trees before spraying and firmly pack the earth about the 

 bases. Care should be taken in refilling the tank that no free oil 

 is allowed to accumulate gradually in the residue left at the bottom 

 when spraying with emulsions or oil-water mixtures. 



Miscible Oils. It will be noted that the difficulty to be over- 

 come in the use of oils is to effect their dilution to render them 

 harmless to the plant. This dilution is effected with great accuracy 

 by the kerosene-soap emulsions, and less accurately by the mechani- 

 cal emulsions of oil and water. There have appeared during the 

 last few years various so-called miscible oils, which readily and per- 

 manently mix with water, and can be applied with the same readi- 

 ness and accuracy of strength as the emulsion of kerosene and soap. 

 These oils have for their principal ingredient some form of petro- 

 leum rendered soluble by the addition of a percentage of vegetable 

 oils and cut or saponified with an alkali, and they are, in fact, a sort 

 of liquid petroleum soap. They are sold under various trade names. 



