34: Journal of Agriculture, Victoria. [10 Jan., 1919. 



The tobacco wash, being a vegetable product, is not injurious to the 

 foliage, but, being sufficiently caustic in its nature, acts as an efficacious 

 remedy against the aphides, and for these reasons it is used during the 

 period of growth. Old leaf tobncco or stems are used at the rate of 

 about 1 lb. to 3 gallons water. The tobacco is steeped in the water for 

 ,three or four days, then the mixture is violently agitated, and the solu- 

 tion carefully strained off into the spraying vat. Soap added at the 

 rate of about 1 lb. to every 20 gallons of the tobacco water increases 

 its killing powers, makes it more adhesive, and leaves a heavier deterring 

 residual deposit on the bark. The interstices in which many of the 

 insects reside, as well as the woolly covering on their bodies, protect 

 them, and render the application of the solution as a spray under high 

 pressure essential. By this means the woolly covering is destroyed, 

 and the insects, smeared with the solution, are washed out of the crevices 

 and cast on the ground to die. The nozzle should- be specially directed 

 at the parts where the insects are most plentiful until thoroughly 

 drenched. If it be found that to complete the eradication of the pest 

 from the orchard, a second application is necessary, this should not be 

 neglected. 



Of the oils used against woolly aphis during the dormant stage of 

 the trees, red oil is regarded as the most efficacious. It is sprayed on 

 the trees in the form of an emulsion, and at strength ranging from 

 1 in 15 to 1 in 25, and soap is made the combining agent. To make 

 1 gallon of oil into a stock solution, 1 lb. of hard soap, or its equivalent 

 of soft soap, is boiled in 2 gallons of water until it is dissolved. Then 

 the oil is poured in, and the mixture put into the bucket spray-pump 

 and forced through the nozzle back on itself, until emulsified, when 

 water may be added to bring the solution to the strength desired. 

 Should the oil show a tendency to separate, this may be prevented by 

 adding a little crystallized carbonate of soda solution, and by keeping 

 the mixture well agitated. Spraying with red oil emulsion may be 

 commenced as soon as the leaves have fallen, and continued while 

 occasion demands it; but as the Bordeaux mixture is applied in early 

 spring, the interim should be as long as possible, so that a comparatively 

 active residual deposit of the former may not be present to impair the 

 efficiency of the latter spray. 



Trees should hot be sprayed for woolly aphis with red oil, especially 

 at the ordinary strength, after the leaves appear. This refers more 

 particularly to those which have become debilitated through being 

 water-logged, or owing to the attack of root borers, or when they have 

 become the hosts of fungi, especially Armillaria mellea. 



Plate 186, illustrating a Eokewood tree affected by woolly aphis, 

 and weakened by root borer as well, clearly shows the evil effects of late 

 spraying. This variety is one most subject to woolly blight, which 

 largely attacks the fruit spurs. The strong oil emulsion injuriously 

 affected the young foliage, as well as the extensive areas of tender bark 

 on the numerous intersticed and developing excrescences. The tree 

 was sprayed the year before being photographed. The main leaders have 

 all been killed, but the basal growths, which supervened on root 

 borer infection, were not injured. 



Although Gargoyle and other prepared soluble oils make good insect 

 destroyers, the most generally satisfactory results are obtained from the 



