1908.] Insect, Fungus, and other Pests. 



509 



to be infested with the mildew Phyllactinia coryles, Karst. 

 The fungus first appears on the leaves, but subsequently 

 renders the fruit useless. All fallen leaves should be collected 

 and burned. The fungus grows on many different kinds of 

 wild and cultivated plants, and there is the chance of its passing 

 from one plant to another. 



Diseased Montbretia Tubers. — These were found to be injured 

 by Mystrosporium adustum, Mass. Several closely allied species 

 of Mystrosporium attack corms, bulbs, tubers, rootstocks and 

 fleshy underground parts of plants generally, and are recognised 

 by the blackened or scorched appearance of the part attacked. 

 The plants in this case started to grow freely and looked well 

 up to the end of July, after which the leaves and stems 

 became brown and withered. 



When a plant is once attacked it should be removed at once 

 and burned, before spores are formed. The earliest symptom 

 of the presence of the parasite is the wilting of the foliage, 

 accompanied by blackened stains on the surface of the under- 

 ground portion of the plants. 



Diseased Pear Leaves. — A specimen of pear leaves from 

 Winchester was affected with the fungus Gymno sporangium 

 clavariceforme, Jacq. The spermogonise are situated on the upper 

 surface of the leaf, the secidia or cluster-cups on the under sur- 

 face. The teleutospore condition grows on localised portions of 

 the branches of the common juniper, the affected parts becoming 

 thickened and distorted. The mycelium is perennial in the 

 tissues of the juniper. The teleutospores ooze through the 

 bark in the form of slender orange gelatinous bodies up to half 

 an inch in length. They germinate in situ, and the minute 

 secondary spores are conveyed to pear leaves by wind, insects, 

 &c. (see also Journal, May, 1908, p. 115). 



English Potato Scab. — Potatoes from Ceinws (Mont.) were 

 affected with the English scab (Spongospora scabies, Mass.). 

 This fungus was in 1846 named Tuburcinia scabies, Berk., by 

 Berkeley. In 1877 Fischer de Waldheim removed the fungus 

 to the genus Sorosporium? and it became Sorosporium scabies, 

 Fisch. In 1886 Brunchurst described a destructive organism 

 on potatoes as Spongospora solani, Brunch., and this species 

 was in reality the pest previously named by Berkeley, although 

 not recognised as such by Brunchurst. Under the circumstances 



