1128 
poorly the following year or fail to start 
at all. 
“When a new growth of leaves in 
autumn follows summer defoliation by 
hoppers, mildew, or other causes, the ef- 
fect is even worse. The new shoots which 
start exhaust what food reserves the 
vine possesses, and the leaves are killed 
by the early winter frosts before they 
have been able to return the supplies they 
have taken from the canes. Similar, but 
less severe, effects have been observed 
following a bad attack of mildew. 
“This starvation of the canes and buds 
may be brought about in another way, 
namely, by the production of too large a 
crop. It is often possible, by excessive- 
ly long pruning, ie cause a vine to pro- 
duce an abnormally large crop of grapes. 
The larger the crop the more material it 
takes from the vine, and if too large, 
the vine is unable to support it and at 
the same time lay up reserve materials 
in its canes and buds. In consequence, 
an extra large crop is often followed by 
weak growth in the spring, and a con- 
sequent small crop the following autumn. 
Vines of heavy bearing varieties may 
even be killed in this way, by repeated 
long pruning 
“This fact has been long recognized 
by practical grape growers. Lately, Pro- 
fessor L. Ravaz,* of the National School 
of Agriculture at Montpellier, France, 
has advanced the opinion that the death 
of vines, as a consequence of overbear- 
ing, is much commoner than is usually 
supposed. This overbearing may occur 
as a@ consequence of various conditions 
other than long pruning. Some seasons 
are peculiarly favorable to heavy crops. 
Certain diseases and injuries induce tem- 
porary heavy bearing. Whatever the 
cause of abnormally heavy crops, Profes- 
sor Ravaz believes that they may result 
in the death of vines. This is the ex- 
planation he gives of the death of large 
numbers of vines in Southern France, 
Algeria, and other countries, and he 
ascribes our so-called Anaheim disease to 
the same cause. 
* “Influence de la surproduction sur la Vege- 
tation de la Vigne,” by L. Ravaz, Coulet et fils, 
Montpellier, 1906 
ENCYCLOPEDIA OF PRACTICAL HORTICULTURE 
“This is substantially the explanation 
given of the dying of vines in Santa 
Clara, in Bulletin 134, which was pub- 
lished before the region was declared 
infested by Anahewm disease. Whether 
this explanation is sufficient is still doubt- 
ful, though it is rendered probable by the 
fact that healthy young vineyards are 
now growing in Santa Clara, on the 
same soil where vines have been killed 
by Anaheim disease.” 
GRAPE PESTS 
Achemon Sphinx or Hawk Moth 
Pholus achemon Drury 
Family Sphingidae 
Philampelus achemon Drury 
General Appearance 
The adult moth is of a brownish-gray 
color with light and dark variegations 
and well defined dark brown spots. The 
hind wings are rich pink with brown 
border and dark spots. The body is red- 
dish gray with two deep brown triangu- 
lar spots on the thorax. The expanded 
wings measure easily four inches across. 
The larva or caterpillar is first green, 
changing to reddish-brown as it grows 
older. The dorsum is brown with from 
six to eight whitish, oblique bars along 
the sides. The pupae are rich brown. 
Life History 
The eggs are green and round. The 
winters are passed in the chrysalis stage, 
the adults emerging about the time the 
foliage appears upon the grapevines. 
The eggs are glued to the leaves and 
hatch in a comparatively short time into 
small green caterpillars. These are rav- 
enous feeders, grow very rapidly and do 
much damage to the foliage of the vines. 
In about one month they are full grown 
and go into the ground to pass the winter 
in the pupal stage. 
Food Plants 
The caterpillars feed upon wild and 
cultivated grapevines and the Virginia 
creeper. 
EH. O. Essie 
Appts Lear Hopper. 
Brack SCALE. 
Buister Mires. 
See Apple Pests. 
See Apricot Pests. 
See Pear Pests. 
