16 MASS. EXPERIMENT STATION BULLETIN 409 



Grape Flea Beetle — Altica chalybea (Illiger) 



In some parts of Massachusetts the grape flea beetle is a destructive pest of 

 grape buds in the early spring. This greenish-blue jumping beetle about 1/5 

 inch long eats into the buds when they are ready to burst and may materially 

 reduce the crop. The larvae feed on the upper surface of the leaves for three or 

 four weeks during May and June. When the grape flea beetle is abundant, 

 spraying with lead arsenate, 4 pounds in 100 gallons, just before the buds open 

 gives satisfactory control. Usually, however, spraying with arsenicals during 

 the early summer, as for grape berry moth control, kills the larvae and keeps this 

 pest in check. 



Grape Cane Girdler — Ampeloslypter ater (Lee.) 



The grape cane girdler has become increasingly abundant in eastern Massa- 

 chusetts since 1938. This tiny black snout beetle makes a ring of punctures 

 around the new cane a few inches from the tip causing it to break and fall or to 

 hang suspended. The egg is usually laid just below the point of girdlmg and the 

 grub feeds for about a month as a borer in the pith of the new cane. Beetles 

 emerge about the middle of August and go into hibernation under trash soon 

 after. There is one generation annually. 



Spraying with lead arsenate prevents the beetles from girdling the canes but 

 the new canes grow so rapidly that applications must be made every three or four 

 days to protect the new growth. Hand-picking of the girdled canes is the usual 

 method practiced. When this is done the cane should be pinched off two or three 

 inches below the point of girdling in order to destroy the egg or grub. 



Japanese Beetle — Popillia japonica Newman 



In some areas in Massachusetts, especially near the larger cities, the Japanese 

 beetle has become established and grape leaves are one of the favorite foods. 

 The fruit is not attacked. The Japanese beetle is about 3/8 inch long and nearly 

 as wide. It is generally brilliant green in color with reddish brown wing covers 

 and alternate black and white bands or spots on its abdomen. The beetles skele- 

 tonize the leaves during July and August but the grubs, which live in the soil, 

 feed on grass roots and are a serious pest of turf. 



The recommended treatment is spraying with 6 pounds of lead arsenate and 

 4 pounds of flour in 100 gallons of water when the beetles appear, but since this 

 may leave considerable residue en the fruit, a repellent spray composed of 20 

 pounds of hydrated lime and 3 pounds of aluminum sulfate in 100 gallons may be 

 preferred. 



DESTRUCTIVE DISEASES 



Black Rot — Guignardia hidwellii (Ell.) Viala & Ravaz 



Black rot is the most common and destructive disease of grapes in many vine- 

 yards. It attacks all green parts of the vine. Infections on the stems, fruit 

 stalks, and leaf veins develop into small sunken cankers which may cause girdling. 

 On the leaves circular reddish-brown spots which grow together cause large 

 irregular dead areas and are dotted with minute black pustules on the upper 

 surface. On the berries infections appear as circular sunken purplish-brown 

 spots, the centers of which are dotted with small black pustules. Infected berries 

 rot, turn black, and dry into wrinkled mummies that are covered with slightly 



