10 BULLETIN 903, U. S. DEPARTMENT OF AGRICULTURE. 



port the insect from one district to another. At times grapes are de- 

 livered to the wineries in greater quantities than can be handled, 

 and boxes of grapes are unloaded and left at the winery instead of 

 their contents being emptied into the elevators and the empty boxes 

 returned to the same wagon. Boxes are exchanged, and some from 

 infested districts find their way to uninfested vineyards. Wander- 

 ing larvae (wanderers) easily shelter themselves in cracks and joints 

 of boxes while these remain strewn throughout the vineyard waiting 

 to be filled with grapes, and when the "boxes are transferred to other 

 vineyards, after having been emptied at the winery, the insects may 

 be released by the shock of the empty box against the ground in 

 the process of unloading. 



In their practical experience, certain grape growers have noticed 

 that the first signs of phylloxera in their vineyards appear at places 

 where they have been in the habit of dumping boxes for the con- 

 venience of grape pickers. 



There were a number of wineries, reputed for the excellence of 

 their wines, in the early-infested district around Glen Ellen, Sonoma, 

 and Los Guillicos, and grapes were hauled to them from afar at 

 about the time vines were dying rapidly in their vicinity. This 

 accounts, no doubt, for the several early centers of infestation which 

 appeared in a short period of time in Napa County. 



The pest spread into Napa County from Sonoma County not only 

 along the highway to and beyond the vineyards cited in Prof. Hil- 

 gard's report, but also over the ranges of hills referred to in the same 

 report by means of a mountain road which ran over the divide from 

 Sonoma and descended into a long narrow valley (Brown Valley), 

 which itself opened out into Napa Valley quite close to the city of 

 Napa. At the head of Brown \ alley and almost on the county 

 boundary line is the Dell vineyard. From the owner. Mr. C. Dell, 

 the following information was obtained : In 1867, 20 acres of Mission 

 grapes were planted with cuttings obtained from the Wing vineyard 

 (then owned by Buhman Bros.), material for which formerly had 

 been secured from the Buena Vista district at Sonoma. After seven 

 years the Dell vineyard began to show signs of phylloxera in small 

 patches, but bore good crops for four years. The Wing vineyard, 

 located close by, began to die at the same time. 



The phylloxera was introduced in this case probably by means of 

 picking boxes, or else by rooted vines planted to fill out places where 

 the cuttings had failed. If the dates are correct, the infestation 

 would have been noticed, without the cause being known, in 1874, or 

 about the time it was discovered along the Sonoma highway. 



The above data are recorded to indicate how important a role this 

 Sonoma Creek district played in the first introduction of the insect 

 into California and how the spread occurred through different chan- 



