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 V 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- 
