New Yorx AGRICULTURAL EXPERIMENT Station. 437 
GRAPE-VINE SAW FLY. 
(Blennocampa pygmaea. ) 
Description.— The larva of this saw fly is a yellowish green 
slug, with numerous rows of black dots across the body. They 
feed together principally upon the under sides of the leaves. The 
life history of this species is similar to that of the currant saw-fly. 
See page 426. There are two annual broods. 
Treatment.— The infested vines should be sprayed with helle- 
bore, one ounce to two gallons of water. If the spraying is not 
done until the larvee are half grown or over, use one pound of hel- 
lebore to one gallon of water. Much pains should be taken to wet 
the under surfaces of the leaves. Paris green, one pound to 150 
gallons of lime and water, may be used before the grapes are 
half grown. 
PEACH DISEASES. 
Caution.— Before discussing the diseases and insect enemies of 
the peach, attention should be called to the fact that the foliage 
of stone fruits and especially of the peach is peculiarly liable to 
injury from Paris green, London purple or copper in solution. 
For this reason the former should not be used stronger than one 
pound to about three hundred gallons of water and at least two 
or three times as much freshly slaked lime as poison should be 
used. It is doubtful whether more than two sprayings with Paris 
green or London purple should be given even if diluted to the 
strength just stated. If Bordeaux mixture is used especial care 
should be taken to have an excess of lime in the mixture. 
CROWN GALL OR ROOT KNOT. 
Description, etc.— In this disease large knots appear on the 
roots. The knots are irregular in form, rough on the surface, 
sofe and spongy within and of various sizes, from the size of a 
pea to the size of a fist. They may occur on any part of the root 
system, but are found most commonly at the point where the 
roots branch off from the trunk; hence the name crown gall. 
