184 INTERNATIONAL CONGRESS OF VITICULTURE 



Spread. 



As there exists in California no aerial form of the insect, there is con- 

 sequently neither sexed form, winter eggs, nor gall louse, as far as present 

 investigations have been able to discover, although these may at rare inter- 

 vals accidentally occur; there is, therefore, practically no danger in spread- 

 ing the pests if cuttings be used for planting vineyards in uninfested districts, 

 even though obtained from an infested one; providing, however, they be 

 made late in the fall of the year, and not buried in infested ground while 

 awaiting shipment. Cuttings are very safe if free of adhering soil, and 

 especially if submitted to the warm water method of disinfection. Rooted 

 vines are dangerous, and require a careful cleaning of the roots for dis- 

 infection to be effective. 



The wanderer, apterous migratory larvae, is the only means of spread 

 due to the natural effort of the insect. 



As already mentioned, the reason the phylloxera is so widely dis- 

 tributed over the State is because of the great activity in planting of vine- 

 yards in different districts which occurred during a period of years extend- 

 ing from 1880 to, and as late as, 1892. First, in the southern portion of 

 Sonoma Valley, and Napa Valley, then in Livermore Valley, and later in 

 the Santa Clara Valley. 



Vineyard troubles in Southern California were due more to other causes 

 than to phylloxera. In Fresno, the Muscat Raisin District, the phylloxera has 

 been present for more than twenty years. The spread is slow, and the 

 vines show a remarkable resistance before dying. In the Stockton district 

 infestation dates back to the early SO's. While in the raisin district 

 of Sutter County, where Thompson Seedless (Sultanina) grapes are almost 

 exclusively used for raisins, the infestation is of more recent date, probably 

 twelve years or so and due to one of the few wine grape vineyards. 



In every instance the spread is slow, and the Vinifera varieties in 

 general give evidence of a longer resistance to the injury of the insect 

 than in Europe. 



Centers of Early Infestation. 



The grape phylloxera is not a native of the Pacific Coast. It was im- 

 ported to California, and contrary to the current impression that the early 

 European importations of grapes to the State are responsible for the intro- 

 duction of this pest, there is greater probability that it was brought over 

 from its native habitat east of the Rocky Mountains prior to that. 



Without consulting any other source of information than the first 

 annual report of the California Commission of Viticulture published in 1881, 

 this fact can be made evident. 



During the early settlement of California the Mission fathers brought 

 over with them, among other European plants, a Vitis vinifera variety of 

 grape, now known as the Mission Grape, and the first cultivated grape to 

 be grown on this Coast. There may have been other varieties brought over 

 during the same period; if so, this one proved itself of superior adaptability, 

 gave better satisfaction and was the only one propagated. The fruit has a 

 delicate flavor, is very sweet and very palatable. The vine is prolific and 

 but little subject to fungus diseases. For years it answered all requirements 

 of both table and wine grape. 



