36 MISC. PUBLICATION 657, U. S. DEPT. OF AGRICULTURE 
If directions for aphid control are given on the container of the 
nicotine solution as purchased, these should be followed. Pyrethrum 
and derris compounds have also been used successfully against aphids. 
Dormant sprays, either oil emulsions or lime-sulfur, applied before 
growth starts in the spring give best control. See formulas for these 
on pages 53—54. 
Nicotine and its compounds are violent poisons, and care should 
be exercised in their use. Exposure to fumes and sprays for any 
length of time causes acute nausea in some persons. Susceptible 
persons should protect themselves with a respirator provided with 
pads saturated with a solution of citric acid. If concentrated 
solutions of nicotine are spilled on the skin they should be 
washed off with water immediately. The operator should not 
continue working in outer clothing which has become wet with 
nicotine-containing sprays, as the body will take up the nicotine 
from the clothing. In mixing the dust avoid inhaling much of it, 
as it may irritate the nose and throat. 
Scale Insects 
Although scale insects are not likely to cause serious damage to 
seedlings that are left in the nursery for only 1 to 3 years, the stock 
should be kept free from scales, since there is danger of transporting 
the pests to the field. The most common control measure is to spray 
with a dormant-strength miscible oil, oil emulsion, or lime-sulfur 
during the dormant period of the trees, preferably in the spring just 
before the buds open. Such sprays are on the market under different 
proprietary names and should be used according to the directions of 
the manufacturers. With the dormant strengths of the heavy oils 
there is a possibility of injury to some of the ‘thin-barked seedlings. 
During the growing season a summer white-oil emulsion or a summer 
strength of lime-sulfur may be used, but these usually are not so 
effective eas the dormant sprays. 
Usually none of these treatments will give complete control in one 
season, and consequently, if only a small part of the nursery stock 
is infested, that part should be destroy ed and not sent to the field. 
Under more serious conditions it is possible that fumigation might be 
needed for some of these scale insects at the time of shipment. 
When using sulfur, especially as a dust, care should be taken 
to avoid getting it into the eyes. If the eyes are affected, do not 
rub them. It is well to wear goggles and a respirator. 
Spittle Bugs 
Often a strong stream of water will effectively control spittle bugs 
by dislodging them from their protective covering of spittle. Contact 
sprays under strong pressure can also be used. 
Recent tests indicate that a 1-percent DDT emulsion or wettable 
powder will control the nymphs of Aphrophora parallela Say and 
A. saratogensis in spittle masses on pines. Promising results have also 
been obtained by applying DDT from the air at the rate of 1 pound 
per gallon of fuel oil per acre, provided it is done when the adults are 
activ e. 
