30 MISSOURI AGRICULTURAL EXPERIMENT STATION BULLETIN 176 



vere the leaves turn brown and drop prematurely. This is perhaps the most 

 common and most injurious pest of grapes in this state. 



The pest passes the winter in the adult winged stage in rubbish in the vine- 

 yard or nearby along fences or where dry grass, leaves or other protection is 

 found. Early in the spring the adults may extract sap from other plants until 

 the grape foliage develops when they attack it and lay their eggs in the lower 

 surface of the leaves. Virginia creeper on buildings is also similarly attacked. 

 In Missouri several generations are developed each year, the pest becoming 

 more abundant and injurious toward fall. 



CONTROL. Clean culture in and near the vineyard especially in the winter 

 to destroy the overwintering adults is the first practical treatment to apply. 

 When the pest is abundant spray with nicotine sulphate using one-half pint to 

 fifty gallons of water when the early brood of nymphs begins to appear on the 

 lower surface of the leaves. Use a penetrating mist spray and make sure that 

 the lower surface of the leaves are thoroughly sprayed. If not entirely effec- 

 tive repeat it later for succeeding generations of nymphs. It is not effective in 

 killing the winged adult. Sticky shields have now largely given way to sprays. 

 In the nursery the pest can be very effectively controlled with the nicotine 

 spray. 



Leaf-feeding Beetles and Caterpillars (Spp.*). In Missouri, the rose 

 chafer and the grape-vine flea-beetle are the two most important beetles attack- 

 ing grape foliage. . The grape root-worm and the adult leaf-feeding beetle is 

 present but thus far has done no appreciable injury. Of the caterpillars, the 

 leaf-folder, the eight-spotted forester, and the plume-moth are most commonly 

 found injuring the foliage of grape. A number of other species feed on grape 

 but only rarely destroy much foliage. In the nursery the leaf-roller is usually 

 the only species that requires attention. 



CONTROL. Where the foliage of grape is being injured by chewing insects 

 one or more applications of an arsenical spray will usually destroy the pest and 

 save the foliage and fruit. In case of the rose-chafer poison sprays are less 

 effective. For this pest use three pounds of powdered arsenate of lead and 

 two quarts of a cheap grade of molasses to fifty gallons of water. The molas- 

 ses hides the taste of the poison and the stronger spray will kill many of the 

 beetles. However, one should supplement the sprays with hand work as the 

 foliage may be badly damaged in a few hours in case of a severe outbreak. 

 Where sprays are to be applied do not wait until the leaves are folded or until 

 the pest has done serious damage. On a few vines hand work will prove en- 

 tirely effective. 



Grape-berry Moth (Polychrosis viteand). This small caterpillar is 

 more or less injurious every year on the fruit. . It is to the grape what the 

 codling moth is to apple. There are normally two generations a year. The 

 winter is passed in the pupa stage on the grape leaves. The adults emerge and 

 lay eggs so that the young worms are ready to begin feeding on the young set- 

 ting fruits. These mature and the second generation of worms work on and 

 in the fruit toward ripening time. 



The caterpillar varies in color from greenish-brown to purple and when 

 full fed is nearly one-half an inch long. The adult is smaller and darker than 

 tho somewhat resembling the codling-moth in general wing markings. The 

 presence of the pest on grape is easily detected by the reddish blotches on 



