1130 
ering almond, pecan, potato, nightshade, 
Bermuda grass. 
Control 
Artificial control by sprays and fumiga- 
tion are never practiced because of the 
efficiency of natural enemies. This is the 
one case where nature controls perfectly 
a serious pest. 
Predaceous Enemies 
The common Vedalia (Novius cardi- 
nalis) and the Koebele’s ladybird (Novius 
kKoebeler) are the ladybird beetles which 
keep the cottony cushion scale in com- 
plete subjection. In many localities in 
California the former is the most effi- 
cient, but in some places, and especially 
in Ventura county, the writer found the 
latter doing most of the control work. 
While these ladybirds are usually 
present in limited numbers in most sec- 
tions, yet at times they completely dis- 
appear and the cottony cushion scale in- 
creases so aS to cause considerable dam- 
age before the beetles can again be estab- 
lished. It is always well to keep a close 
watch of this pest, and if it appears 
without being accompanied by the larvae 
of the Vedalias, adults of the latter 
should be obtained and liberated as soon 
as possible. 
True Parasites 
There are two true parasites which 
also prey upon this coccid: the hymen- 
opterous enemy, Ophelosia crawfordi, 
and the dipterous parasite, Cryptochaetum 
(Lestophonus) iceryae Will. The latter 
is often responsible for as much effective 
work as are the Vedalias, though this 
fact is not generally known. 
E. O. Essie 
Corrony Marte Scare. See Apple Pests. 
Curworms. See Index. 
Erinose* 
Erinose is a disease of the vine char- 
acterized by swellings on the upper sur- 
face of the leaves, and corresponding de- 
pressions on the lower surface. These 
swellings, when numerous, cause consid- 
erable deformation of the leaves, but not 
* Revised from Bulletin No. 186, by F. T. 
Bioletti and BH. H. Twight, by H. J. Quayle, 
California Experiment Station. 
ENCYCLOPEDIA OF PRACTICAL HORTICULTURE 
the change of color to yellow or brown 
which is characteristic of most fungous 
diseases. Even very badly affected 
leaves retain almost their normal green 
color on the upper surface until late in 
the season. The depressions on the under 
side are coated with a thick felt-like cov- 
ering, which, at first pure white, grad- 
ually turns rusty and finally becomes 
dark brown. Generally, the swellings 
and corresponding depressions are iso- 
lated and few in number on the affected 
leaves, but In severe cases they are nu- 
merous enough to become confluent and 
the whole lower surface is then com- 
pletely hidden by the felt-like covering. 
Occasionally, indeed, the felt-like mate- 
rial extends to the upper surface in nar- 
row strips bordering the veins, and may 
even be found on the petioles and flower 
clusters. 
Many have the impression that they are 
attacked by a fungus, and, in fact, the 
coating has a strong superficial resem- 
blance to some fungous growths. A mi- 
croscopic examination shows, however, 
that it consists of a mass of hypertro- 
phied hairs or abnormal outgrowths of 
the epidermal cells of the leaf. They are 
larger, more abundant, and more per- 
sistent than the normal leaf-hairs of the 
leaf, and differ also in being often 
branched and usually unicellular. This 
abnormal growth, in common with simi- 
lar growths found on other plants, is 
called an erineum, from a Greek word 
meaning woolly. This is the derivation 
of the word erinose, which means woolly 
disease—a very appropriate name. The 
erinea of leaves were formerly supposed 
to be of fungous origin, but are now 
known to be due to the attacks of minute 
mites. The feeding of these mites exerts 
a stimulating effect upon the epidermal 
cells of the leaf, which causes them to 
grow out into the abnormal hair-like pro- 
cesses already described. The mite caus- 
ing erinose of the vine is known as 
Eriophyes vitis, and is related to the 
mites causing a similar disease of the 
walnut and the leaf blister of the pear, 
both of which are very common. 
The Hriophyes vitis is not a true in- 
sect, but a mite or acarid belonging to 
