II April, 1910.] 



Erinose of the Vim. 



J03 



ERINOSE OF THE VINE. 



G. H. Adcock, F.L.S., Principal, Yiticultural College, Riither^len. 

 {Adapted from a Lecture given to College Students, 21st Fehrnary, igio.) 



During the current season Mr. P. A. Wyatt, my travelling assistant, 

 has brought me from time to time numbers of vine leaves obtained from 

 young imported vines. These leaves had the peculiar galls or swellings 

 which seemed to indicate Erinose which is common enough in Europe and 

 California, but up to the present season was unknown in Victorian vine- 

 yards. To make absolutely sure we appealed to the microscope, and during 

 a careful examination the acarids which are responsible for the appearance 

 of the leaves were distinctly visible. This was further confirmed by Mr. 

 D. McAlpine, Government Vegetable Pathologist, to whom leaves (also 

 thought to be invaded by some fungus) were submitted for investigation. 



The swellings or galls, 

 of which an excellent 

 figure has been drawn 

 from nature by Mr. T. A. 

 Brittlebank, House Mas- 

 ter at the College, are a 

 distingushing feature of 

 Erinose. They are found 

 on the upper page of the 

 leaf, and are generally iso- 

 lated, though in severe 

 attacks the swellings may 

 be confluent. On the cor- 

 responding position on 

 the under surface of the 

 leaf there are depressions, 

 covered with what looks 

 superficially very like the 

 mycelium of a fungus. 

 The microscope, how- 

 ever, reveals no fungus 

 in true Erinose, and the 

 felt-like mass is in reality 

 but an aggregation of 

 abnormal leaf hairs, stimulated into an irregular and unusual growth by 

 the irritation of the tiny parasite. 



From the appearance of these patches on the under surface of the leaf, 

 the name Erinose has been given. It is singularlv appropriate, being 

 derived from a Greek word meaning woolly, and has reference to these 

 apparently woolly patches. In the early stages of attack the hairs are 

 white, but they gradually darken in colour till they become brown. 



Coming now to the minute parasite that is responsible for the appearance 

 of the vine leaves attacked, we find it is not a true insect, but a tiny mite. 

 Though only about i -250th part of an inch in length, it is active and vigor- 

 ous in its movements. It belongs to that division of jointed animals which, 

 from the skill of some representatives in spinning, was dedicated to the 

 mythical Arachne. She regarded herself in her vanitv as holding the 

 world's record in this and kindred arts, and for her presumption and 



LEAF SHOWING ERINOSE. 



