226 NEBRASKA STATE HORTICULTURAL SOCIETY 



if used iu the proportion of one gallon of the Black Leaf in sixty-five 

 to seventy gallons of water. In fact, we have usually been successful 

 when using Black Leaf as weak as one gallon to 100 gallons of water. 

 This strength, however, requires very thorough application. It would 

 be a good plan for anyone to treat a few trees with varying strengths of 

 this or any other insecticide for the destruction of lice a day or two 

 before taking up his general spraying work, for the purpose of deter- 

 mining whether or not the strength that he contemplates using is suffi- 

 cient to kill the lice. In this way he may save many dollars, from using 

 the insecticides in a strength that will not do the work or in a propor- 

 tion unnecessarily strong. 



Tobacco Decoction. — If any prefer to make their own tobacco de- 

 coctions, they may use tobacco stems or tobacco dust or whole leaf 

 tobacco. Fruit men, however, have not reported very uniform resuls 

 from their own preparations. This may be due to adulterations in the 

 tobacco or from different methods of preparing the decoction. For the 

 preparation of tobacco decoctions see under Preparation of Insecticides, 

 below. 



Lime-Sulphur Sprays. — The lime-sulphur sprays have not been suc- 

 cessful in destroying the woolly aphis during the summer season when the 

 body is covered with the woolly secretion. It has been fairly successful 

 when applied two or three weeks before the buds open for the de- 

 struction of the little lice that live over v/inter upon the trees and which 

 do not have their bodies protected by the secretion. 



Late lYiiiter or Early Spring: Work 



So far, the remedies mentioned have been for summer treatment, 

 when the bodies of the lice are more or less covered with the waxy se- 

 cretion. We believe the best time to get results in the treatment of this 

 louse is late in the winter or early in spring before the buds open. This 

 is not bepause the lice get protection from the opening buds, but because 

 by the time the buds have opened, the lice have their bodies more or less 

 covered by the waxy secretions that protect them to some extent from the 

 effects of the insecticides. 



.• Orchards in the Grand valley, Colorado, treated eary in the spring 

 of 1907 for the destruction of the eggs of the green-apple aphis were 

 also largely freed from the woolly aphis. The insecticides that were 

 found successful in the destruction of these little overwinter lice were: 

 Lime fifteen pounds, sulphur fifteen pounds, water thirty gallons. Lime 

 fifteen pounds, sulphur fifteen pounds, water forty-five gallons. Rex 

 lime-sulphur one gallon, water seven gallons, lump lime two pounds. 



Lime fifteen pounds, sulphur fifteen pounds and water sixty gallons 

 was a little weak and did not give results that were fully satisfactory, 

 and the same was ti'ue of Rex one gallon, water seven gallons, without 

 the addition of lime. 



Trealnieut Below Ground 



Thte treatment below ground is all aimed at the lice that are within 



