GRAPE PESTS 15 



generation. The larvae of the second brood feed in ripening berries, often enter- 

 ing several berries before building a winter cocoon in the fold of a leaf. 



Control of the grape berry moth is greatly facilitated by regular burning of 

 the fallen leaves in early winter and cultivation under the vines in the spring. 

 The recommended spraying treatment is an application just after the blossom 

 period and again when the young grapes are nearly touching in the cluster, using 

 l}4 pounds of lead arsenate in a 4-4-50 bordeaux mixture. The addition of J^ 

 pint of fish oil or raw linseed oil as a sticker and spreader is very advantageous. 

 These sprays to combat the first generation caterpillars should be applied very 

 thoroughl)' and carefullj' because later sprays to combat the second generation 

 caterpillars may leave an undesirable residue and should be avoided if possible. 



Grape Lea/hopper — Erythroneura comes (Sa\) 



The grape leafhopper is usually present in Massachusetts vineyards but it is 

 not abundant every year. The hoppers suck the plant juices from leaves, giving 

 them a mottled appearance, and badly infested vines usually produce small 

 and poorly flavored fruit. The adult is about 1/8 inch long and very agile, hop- 

 ping and flying in quick darts or running rapidly in any direction. It is light 

 yellow in color with several red spots and bands which vary in pattern with 

 individuals. 



The insect hibernates as the adult, emerging in the spring and laying eggs in 

 the veins on the under surface of the leaves in June. The young nymphs, which 

 are white with red eyes, feed on the leaves until midsummer when they develop 

 into adults. A second brood of nymphs usually develops in September but many 

 of these do not become fully grown before cold weather. 



The grape leafhopper is controlled by spraying with 40 percent nicotine sul- 

 fate at the rate of 1 pint in 100 gallons, or IJ^ teaspoonfuls in 1 gallon. The 

 nicotine sulfate is usually added to bordeaux mixture and lead arsenate to make 

 a combination spray (See Spray Schedule). It is most effective if applied when 

 the nymphs are about one-half grown, usually in late June. It may need to be 

 repeated about Sept. 1 at which time the lead arsenate and bordeaux mixture 

 should be omitted. 



Grape Root-worm — Fidia viticida Walsh 



The grape rootworm is a potential pest of grapes in Massachusetts but is 

 seldom destructive here. The beetle is small, hairy, and chestnut brown in 

 color. Injury by the beetles consists of chainlike holes eaten in the foliage, and 

 the grubs feed on the roots. 



Calcium arsenate or lead arsenate, preferably combined with bordeaux mixture 

 as for grape berry moth, controls the beetles if applied when the adults first appear, 

 soon after the grapes have blossomed. 



Brown Grape Aphid — Macrosiphum illinoisensis (Shimer) 



This insect attacks the tender growing shoots and leaves, but occasionally it 

 becomes so abundant that the honeydew which is secreted falls on the fruit and 

 makes it sticky and gummy. Tb's aphid spends the winter in the egg stage on 

 the hawthorn from which the winged migrants fly to the grape where seven or 

 eight generations may develop throughout the summer. Ladybird beetles and 

 other natural enemi^ greatly reduce the populations of the brown grape aphis. 

 It can be well controlled by spraying with 40 percent nicotine sulfate at the rate 

 of 1 pint in 100 gallons. 



