A fe:w orchard pdant dice 15 
above trade name and which has become very popular among the 
orchardists of Delta County as a spray for all plant lice in their 
orchards. Purchased in car load lots, it is one of the cheapest, 
and most easily prepared, of all spray materials used, and has 
given remarkable satisfaction, and in our experiments it has given 
splendid results. Aside from the fact that it does not penetrate 
the woolly covering of the lice quite so readily as the kerosene emul¬ 
sion, we are inclined to place it about on a par with that insecti¬ 
cide in its killing effects. When this, or any other spray, is used, 
special care must be taken to throw the spray from all directions 
and under high pressure, 140 to 180 pounds, if possible, to get 
best results. The manufacturers write us that they take great pains 
to put out a uniform product of Black Leaf so far as the nicotine 
content is concerned, and that this is the only ingredient that it 
contains that has any special insecticidal value. This being the 
case, if the manufacturers keep up the present standard of quality 
in this dip, we predict that it will come into very general use fol* 
the destruction of all aphids upon out-of-door plants. 
While the orchardists have been using Black Leaf, in most 
cases, in the proportion of i gallon to 65 gallons of water, we 
have found in our experiments, where we know that thorough 
treatments have been made, that i gallon to 75 gallons of the 
watery mixture is very uniformly successful in killing all the lice, 
and I to 100 (a i per cent, mixture) seldom fails to give excel¬ 
lent results. 
It is a good plan for the orchardist to treat a few trees with 
varying strengths of his mixture a day or two before taking up 
liis spraying in an extensive way, and note carefully the results. 
In this w^ay he may save many dollars, either from using the in¬ 
secticide in strengths that are unnecessarily strong, or by throw¬ 
ing away a large amount of time and material in the application 
of a spray that is too weak to give satisfactory results. 
TOBACCO DECOCTIONS. 
Some may prefer to make their own tobacco sprays, either by 
using tobacco stems, tobacco dust, or whole-leaf tobacco. AVhile 
fruit growers do not report very uniform results from their own 
tobacco preparations, our experience has been different. When we 
have steeped tobacco stems, or tobacco dust, in w^ater in the pro¬ 
portion of I pound to two gallons, or the whole-leaf tobacco in 
the proportion of a pound to four gallons of water, we have been 
very uniformly successful in getting a decoction that would kill 
the lice. See directions for preparing tobacco decoction near the end 
of this bulletin. 
Mr. W. S. Coburn, President of the Colorado State Board of 
