1238 
males and females may be also abundant 
during the winter months. 
Food Plants 
Works on a great variety of plants in- 
cluding the citri and cucurbits. The fruit 
as well as all tender growing parts of 
the plant are attacked. 
Control 
The control of this pest has been some- 
what complicated and unsatisfactory, al- 
though at the present time considerable 
or complete success attends the efforts 
of careful work. Without doubt the best 
control measure is the application of a 
carbolic acid emulsion spray, which 
should be applied plentifully, from ten to 
fifteen gallons to an average size tree, 
and under a pressure of 200 pounds. We 
have found that two angle “Bean Jumbo’”’ 
nozzles on a “Y” to each rod give best 
results. Large-holed discs should be used 
in the nozzles to insure a coarse driving 
spray. 
If the mealy bug is present in great 
numbers it may be necessary to make 
two, three or even four applications a 
week or so apart. 
During the winter, when there are large 
numbers of egg-masses, or in the spring 
when the young are hatching, is the best 
time for applying the sprays. 
Fumigation has often given excellent 
killing results, but is not at all recom- 
mended for this pest, unless some other 
destructive scale insect, such as red, yel- 
low, black or purple seale, is present and 
needs that treatment. Experience has 
shown that an excessive dose gives little 
better result than the ordinary black- 
seale dosage. 
Silver Mite of the Lemon 
Eriophyes oleworus Ashm. 
Phytoptus oleivorus Ashm. 
General Appearance 
The adult mites are so small as to be 
invisible except with the aid of a lens. 
They are light yellow in color, long and 
pointed anteriorly with two pairs of legs 
near the head. The eggs are exceedingly 
small, circular and faintly yellow in col- 
or. The presence of the mite is easily 
told by the characteristic silvery chafing 
ENCYCLOPEDIA OF PRACTICAL HORTICULTURE 
of the skin of the lemon, due to the de- 
struction of the oil cells. In Florida the 
oranges are also chafed, causing a rus- 
seting. 
Life History 
The eggs are deposited singly or in 
small clusters on the leaves or fruit. They 
hatch in less than a week in hot weather 
but require twice as long in cold weather. 
After several molts the mites become full 
grown in from two to three weeks. The 
young and adults feed upon the oil in 
the succulent parts of citrus plants, which 
is obtained by piercing the oil cells with 
their beaks. The adults are capable of 
rapid locomotion and move freely. They 
breed from spring until late fall, giving 
rise to many overlapping broods a year. 
Food Plants 
Works upon bark, foliage and fruits of 
citrus trees. In California its attacks 
are usually confined to the lemon. 
Control 
Same as for the citrus red spider. See 
Apple Pests. 
BE. O. Essig 
Lettuce 
Lettuce is a hardy annual, almost uni- 
versally grown in American gardens, and 
is highly esteemed as a salad plant. It 
is generally grown out of doors from 
seed planted early in the spring, or it 
may be grown by a succession of plant- 
ings at different times during the year. 
It is not easily injured by early or late 
frosts. 
Samuel B. Green, in “Vegetable Gar- 
dening,”’ recommends the following: 
Varieties 
There are many varieties and each year 
finds many additions to the list of those 
offered by seedsmen. In the matter of 
quality, those forming a head like the 
cabbage have the preference. Varieties 
that form only a bunch of leaves are 
largely raised by market gardeners to 
supply the common demand, since they 
are more easily grown and are less liable 
to injury in handling than the heading 
varieties. Some of the most desirable 
kinds are as follows: 
