]^EW York 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 42 G. There are two annual broods. 



Treatment.- — The infested vines should be sprayed with helle- 

 bore, »ne ounce to two gallons of water. If the spraying is not 

 done until the larvae 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, 

 sofo and spongy within and of various sizes, from the size of a 

 pea to the size of a fist. I'hey 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 cro^vn gall. 



