MORE ABOUT THE GRAPE-VINE PEST. 



169 



The American Oak Phylloxera [Phylloxera Rileyi). — There are 

 several described and undescribed species of Phylloxera in this coun- 

 try, most of them inhabiting leaf-galls made on our different hickories. 

 The species herewith figured is the only external* feeder known in 

 America, and it is briefly alluded to in this connection to show that, 

 as with the grape Phylloxera, it does not need a "winter ^^%^^ to 

 enable it to hibernate, but passes the winter in the larva state (as at 



Fig. 9. 



Phylloxera Rileyi.— a, pupa ; 6, winged 

 female ; c, antenna greatly enlarged ; 

 d^ portion of infested leaf. 



Fig. 10. 



Phylloxera Kileyi.— a. b. dorsal and ventral 

 views of larva as seen hibernating ; c, d, 

 highly-magnified leg and antenna of same. 



Fig. 9), firmly attached to the tender bark of the younger twigs, and 

 thus braving all the vicissitudes and inclemencies of that season. In 

 the summer it is found on the underside of the leaves of our white 

 and post oaks, fixed in the centre of a yellowish spot caused by its 

 puncture, and showing most on the upper surface, so that on a badly- 

 infested tree the leaves all look speckled, and seared, and withered. 

 It presents all the different forms and the same biological character- 

 istics that I have described and detailed of the grape Phylloxera. 



CONCLUSION. 



We have, in the history of the grape Phylloxera, the singular 

 spectacle of an indigenous American insect being studied, and its 

 workings understood in a foreign land, before its presence in its most 

 injurious form was even suspected in its native home. The Franco- 

 Prussian War, with all its fearful consequences to France, has passed 

 away; the five milliard francs (one thousand million dollars) have 

 been paid, as indemnity to her victors, in so short a time that the 

 civilized world looked on in wonder and astonishment. Yet this little 

 Phylloxera, sent out, doubtless, in small numbers, by some- American 

 nurseryman, a few years since, continues its devastating work, and 

 costs that unfortunate country millions of francs annually. The last 

 German has been removed from French soil — at terrible cost, it is true 

 — but the Phylloxera army remains ; and, if another five milliard francs 



