194 DISEASES OF TROPICAL PLANTS CH . 



Asterina tenuissima, Fetch, is a fungus which 

 occurs on the fruits and stems of Hevea in the Straits 

 Settlements, causing a blackening discoloration and later 

 a great number of minute black points. It is superficial 

 and does not do much damage. 



Fruit Disease. A species of Phytophthora 1 in the 

 Straits Settlements attacks the fruits of the Para 

 rubber, causing them to turn black. This disease and 

 the organism which causes it are very similar to the 

 black rot disease of the cacao, and should be treated 

 in the same way (see page 188). 



Seedling Disease. Pestalozzia guepini, Desm., is 

 the cause of a leaf disease known as the grey blight. 

 It occurs on the leaves of mature trees of Hevea, but is 

 of no importance. However, it sometimes attacks the 

 stems of the seedlings and becomes very destructive. It 

 has been reported from Java, Ceylon, and probably has 

 a very much wider distribution in the eastern tropics. 



Pestalozzia palmarum, Cooke, which is also a leaf 

 parasite on the coco-nut, tea, and gutta percha, attacks 

 the Para rubber in Java, Ceylon, and other places. 



Helminthosporium hevea is a leaf - spot disease 

 which attacks the large Hevea seedlings in the nursery 

 in Ceylon and the Straits. It occurs as a small circular, 

 semi-transparent spot bordered by a purple brown 

 line. 



A very severe seedling disease has also been reported 

 from Borneo, but without data as to its character. 



Other leaf diseases are Phyllachora Huberi, P. 

 Henn., Dothidella Ulei, P. Henn., Aposphaeria Ulei, 

 P. Henn., Ophibolus hevea, P. Henn., and Parodiella 

 melioloides, P. Henn, on the Para rubber in Brazil, 

 Diplopeltis Zimmermanii, P. Henn., Gloeosporium 

 brunneum, Colletotrichum hevea, Zimm., C. elasticae, 

 Kood and Zehn., C. ficus, Kood and Zehn, Phyllosticta 

 ramicola, P. hevea, in various parts of the East Indies, 

 but are thus far of little or no importance. However, 

 Gloeosporium alborubrum, Petch, on Para rubber in the 



1 P.fdberi. 



