THE AMERICAN ENTOMOLOGIST, 



95 



by the decreased efficiency of its natural 

 enemies. Aside from the parasites men- 

 tioned, the worm is beset on all sides by 

 enemies which cannot work so well during 

 wet weather, and whenever the natural 

 checks are hindered in their work the great 

 prolificacy of the plant-feeder soon gives 

 it the advantage in the struggle for exist- 

 ence. The conclusion is also arrived at, 

 from certain futile attempts made to intro- 

 duce the English sparrow into the South, 

 that this bird cannot be acclimated there, 

 and that while it will extend into the cot- 

 ton belt during winter time it returns fur- 

 ther north in summer, and dies when the 

 temperature exceeds loo'' Fahrenheit. 



FURTHER NOTES ON THE GRAPE PHYLLOXERA 

 IN CALIFORNIA. 



We have received from Prof. E. W. 

 Hilgard of the University of California 

 a supplement to the biennial report of the 

 Board of Regents, which contains over 

 loo pages of very interesting reading, and 

 indicates the thoroughness and energy 

 which the Professor of Agriculture and 

 Botany has brought to the College of 

 Agriculture. We quote some passages of 

 his remarks on the Grape Phylloxera, 

 which indicate the true status of things 

 there, and are suggestive : 



The situation a year ago may be summed 

 up as follows : The ravages of the enemy have 

 become manifest in a greater or less degree, 

 from about six and a half miles above Sonoma 

 Town to the lower end of the valley, a length of 

 ten or eleven miles in all. Within these limits 

 large tracts have been completely destroyed, the 

 vines having been uprooted and grain sown in- 

 stead for several years. It is difficult to ascertain 

 the total area of vineyard that has disappeared, but 

 it counts many hundreds of acres. On a still larger 

 area, probably, the condition of the vines has be- 

 come such as to render them unprofitable, so that 

 they are being pulled up and used for firewood in 

 the wineries. So far, no material difference in 

 respect to the resistance of the several varieties has 

 been reported, all those grown being of the type 

 of the European vine ( J^itis vinifcra), grown on its 

 own or kindred stock. The Mission vine, nat- 

 uralized for over a century in California, is at 

 least as badly attacked as is the Riesling, Zin- 

 fandel. Rose of Peru, or any other grown. 



Amid the general devastation, nevertheless, 

 there are some exceptions — green islands, ap- 

 parently of healthy vines in good bearing, 

 yet surrounded on all sides by defunct vine- 

 yards. This is even the case in the vineyard which 

 first succumbed, where, nevertheless, some of the 

 original vines still remain, apparently in good 



condition. A close study of these exceptions 

 could not fail to lead to highly valuable results ; 

 but to do so would require the whole time of a 

 thoroughly qualified person for at least an entire 

 season. In general it appears that great care of 

 the vines, good tillage, and manuring have been 

 practiced in all these cases ; but there are many 

 others in which no amount of care or manuring 

 has seemed to possess any perceptible efficacy, 

 and where the destruction has been as swift as in 

 the doomed vine3'ards of France. 



Whatever may be the true explanation of these 

 remarkable exceptions, the general fact remains 

 that in four years the insect has spread no more 

 than about two and a half miles up the valley, 

 from a point of great virulence, notwithstanding 

 the fact that this is the prevalent direction of the 

 summer winds. 



The natural inference from this fact would 

 seem to be that from some climatic cause, the 

 Phylloxera in California does not develop into 

 the winged form, which evidently mediates its 

 rapid progress in Europe ; and that its progress 

 is here altogether dependent upon the transporta- 

 tion or migration of the wingless forms. 



It would be most important practically, as 

 well as most interesting theoretically, to verify 

 this inference by observation ; but I have been 

 unable as yet to obtain any observations on the 

 subject, save as regards the general statement 

 that no one has noticed about the infested vines 

 any very small flies in July and August. 



If it were definitely known that the winged 

 form does not make its appearance, then it 

 would follow that the pest can be stamped out 

 by a concerted effort, by using those insecticides 

 which, though locally effective, have failed to 

 prevent the spread of the insect in Europe. 

 Although too costly to be carried out by each 

 one, such method could well be afforded by a 

 community for the purpose of putting an end to the 

 fearful evil, once for all. I mention in this con- 

 nection the sulpho-carbonates, and the clay cubes 

 impregnated with carbon bi-sulphide. It is true 

 that a few dozen of the latter have been tried in 

 a vine3'ard near Sonoma, with no perceptible ef- 

 fect ; but this cannot be a matter of surprise, 

 since the mistake was made of putting them 

 around alternate vines, so that the one intended 

 to be relieved would in any case be promptly 

 restocked fron its neighbors. The vines to be 

 treated should, of course, have been entirely 

 isolated, in order to render the experiment de- 

 cisive. 



As to the presence of the Phylloxera in other 

 portions of the State, extensive inquiries have 

 failed to satisfy me that it exists outside of the 

 Sonoma Valley, save at one point, in Fresno 

 County, where it was introduced with cuttings of 

 choice grape varieties from Europe. The pro- 

 prietor, recognizing the fact in time, and con- 

 scious of the danger incurred by one of the fore- 

 most industries in the State, has used every eflfort 

 to confine the pest within his own vineyard, at a 

 considerable pecuniary sacrifice. 



It must be a subject of congratulation, that 

 with the introduction of such a great number of 

 grape varieties from foreign countries, a larger 

 number of insect pests and diseases has not 

 been introduced. On the whole it may be said 

 that the vines of California are remarkable for 

 their rapid growth, vigor and thriftiness. 



It is noteworthy, in this connection, that so far 

 the varieties derived from the native American 

 grape, which are alrnost exclusively relied on in 



