148 PARA RUBBER. 



occasionally turn black and dry up, and it has been suggested that 

 this may be due to some plant-sucking bug. A species of weevil, 

 allied to if not identical with Astycus lateralis, has been known to 

 eat the leaves of Para rubber in the Straits,* and the only remedy 

 is to collect and destroy the weevils. 



Green has also recorded in the T. A. and Mag. C A. S., Decem- 

 ber, 1905, a new species of scale bug (Coccid) upon the leaves, 

 belonging to the geuus Mytilaspis, but he considers that it is un- 

 likely to cause any serious trouble. 



" Mites " in rubber nurseries have also been reported from the 

 Straits. f Arden states that in some cases the young leaves fall from 

 the plant before they are fully developed, and in other cases the 

 mature leaves present a crinkled appearance, are yellowish -green in 

 colour, and appear to be dotted with numerous punctures. He 

 compares it to " Red Spider/' and believes that the disease is mainly 

 limited to plants growing under unfavourable conditions. 



Spotted locusts have also been reported to do considerable dam age 

 to the young rubber plants in Ceylon and the Straits. 



Locusts have been reported from various districts in Ceylon, and 

 are said to destroy the seedlings and also the leaves of mature 

 plants. According to Green (Tropical Agriculturist, November, 

 1905) poisoned baits have been found effective in such cases, one of 

 the best being "Arsenic salt horsedung " mixture, made b} 7 com- 

 pounding one part of Paris green or white arsenic with two parts 

 salt and forty parts fresh horsedung. It is recommended that this 

 should be broadcasted among the affected plants or wherever the 

 locusts may be noticed. 



Fruit Disease. 

 Para rubber planters in many parts of Ceylon have occasionally 

 been alarmed at the curious behaviour of certain fruits ; some dry 

 up and remain attached to the twigs, and others of all ages fall to the 

 ground without expelling the seeds. The fall of the unexploded fruits 

 is often due to wind, and there is no parasitic fungus to be found 

 in the tissues. It has been stated that the fruits are subject to 

 the attack of a parasitic fungus belonging to the genus Nectria, and 

 CarruthersJ reports having successfully inoculated Para rubber fruits 

 with this fungus, but was not certain as to whether it attacked the 

 fruits when on the tree or only when they fell to the ground. Petch§ 

 subsequently stated that the disease on Para rubber fruits is due to 

 a parasitic fungus similar to, if not identical with, that which causes 

 the decay of cacao pods. All the Hevea fruits examined were 

 attacked by a species of Phytophthora, which permeates the soft outer 

 tissues of the fruits ; the seeds dry up later when the supply of food 

 and water is cut off. In addition to the ordinary spores which infect 



* Wray, Perak Museum Notes, 1897. 



j Stanley Arden, Agr. Bull, of the Straits and F.M.S., June, 1905. 

 t J. B. Carruthers, Circular of the R.B.G., Peradeniya, January, 1905. 

 § T. Fetch, Mycological Notes, Tropical Agriculturist, 1905. 



