﻿OF THE STATE ENTOMOLOaiST. 163 



failure to find here what has been found in France, may be due to 

 the comparative scarcity of the insect with us in 1875, and while I 

 would by no means conclude from it that there is any difference of 

 habit in the insect here and there, it shows how very rare these winter 

 eggs may sometimes be. 



PRACTICAL CONSIDERATIONS GROWING OUT OF THESE LATEST DISCOVERIES. 



Since the announcement that the impregnated egg winters under 

 the loose bark, a number of French writers have proposed plans for 

 its destruction, and urged that such was the readiest way to avert 

 Phylloxera injuries. The plans mostly consist of the decortication of 

 the vines and burning of the bark, and the application to the wood of 

 some oily liquid such as kerosene, that may be applied so as to pene- 

 trate and destroy the egg and not irjure the wood. While granting 

 that the destruction of such eggs in such manner is desirable, espe- 

 cially in a vineyard in an infested neighborhood, but not yet suffer- 

 ing, I doubt whether it is suflBciently important to warrant the labor 

 involved ; for those who advocate such a preventive system most 

 earnestly, forget that by far the larger number of the insects hiber- 

 nate as young larvae on the roots, and that according to Balbiani this 

 same impregnated egg may be produced on the roots from sexed in- 

 dividuals born of hypogean, wingless mothers. 



While it is always best to know the truth, in the present instance 

 it certainly does not give us any advantage over our enemy. Now 

 that we have obtained a full survey of his powers we find no especial 

 weak point by attacking which he can be destroyed. He has too 

 many resources at command. From the practical side it seems to me 

 that the lessons taught by these late discoveries are more discourag- 

 ing than otherwise. There is no chance of managing in any general 

 way the destruction of the eggs on the leaves, and it is evident now 

 that the insect may be imported from one country to another on cut- 

 tings as well as on rooted plants ; and that winter submergence will 

 not eradicate the pest. We furthermore get a better understanding- 

 of the fact that in so few instances the insect has been eradicated by 

 insecticides applied to the soil. One valuable lesson is taught by 

 these facts : it is that the season in which insecticides applied to the 

 roots will do most good, is in the interval between the hatching of 

 the impregnated winter egg and the appearance of the winged females, 

 i. e., during May and June. 



PHYLLOXERA RAVAGES IN CALIFORNIA. 



There is no longer any doubt whatever of the occurrence of Phyl- 

 loxera in California. It has during the year made its presence but too 



