621 



less numerous. In Gironde, for example, where C. amhiguella was 

 formerly abundant, it is now quite rare, although the popular name 

 for it is still used to designate both species. 



The original habitat of these two pests is unknown, but C. amhiguella 

 tends to adapt itself more easily to cool and moist regions and is 

 abundant in the plains, while P. botvana prefers the warm hill-sides, 

 though it is also found in company with the former species in the 

 northern vine-growing regions of Europe, such as on the Rhine and 

 ]\Ioselle. 



Keuchenius (P. E.) & CoRPORAAL (J. B.). Dierlijke Vijanden van 



Hevea brasiliensis. [Animal Enemies of H. bmsiliensis.] — Reprint 

 from Handboek voor de Rubbeycultimr in Nederlandsch- Indie, 

 n.d., sine loco, pp. 216-229, 17 figs. [Received 20th October 1922.] 



Hymenopterous pests of Hevea brasiliensis in the Dutch East Indies 

 are Oecophylla smaragdina, an ant much feared by workers because 

 of its painful bite, and which protects some species of scales infesting 

 rubber, and Ceraiina viridissima, a bee which bores into the cut surface 

 of young stumps after they have been planted, but is of very slight 

 importance. 



Among Coleoptera, the larvae of Dihammus fistidator. Germ., bore 

 into the wood and must be picked out. Xylotrupes gideon feeds on 

 the latex at tap- wounds, but does not rank as a pest. Scolytid beetles 

 attack the trees at points where the bast has been killed or injured, 

 and finally attack the wood in the case of sickly trees. Wounds 

 should be protected with tar, and if the wood is already attacked, the 

 spot may be bandaged with jute material soaked in kerosene, or a 

 coating of tar mixed with fine sand may be used. 



In Sumatra the Psychid moth, Acanthopsyche snelleni, sometimes 

 occurs in large numbers on Hevea and causes injury by feeding on the 

 bark where it has just been tapped. The larval cases should be collected. 



Rhynchota include the following Coccids common on Hevea : 

 Saissetia (Lecanium) nigra. Coccus {L.) viridis, Pseudococcus virgatus 

 and P. citri. There is no record of a definitely injurious infestation 

 by these scales, and it is seldom that they occur so abundantly on the 

 ends of the branches as to prevent growth. The white Flatid, Lai&ana 

 Candida, sometimes appears in Eastern Java in such masses that the 

 trees seem covered with snow. In spite of its sucking the sap no 

 harm appears to result. 



A termite, Coptofermes gestroi, is one of the worst pests of rubber. 

 It does not limit itself to dead wood, and not only infests Hevea but 

 other plants also, such as coconut, kapok and Ficus elastica. Its 

 nests should be traced and destroyed immediately it is observed. 

 A poison-bait composed of 100 parts sawdust and 1 of Paris green 

 is effective, or recourse may be had to an apparatus that pumps in 

 the fumes generated by placing a mixture of 3 parts arsenic and 1 part 

 sulphur on glowing wood charcoal. Other termites found in rubber 

 plantations are harmless. 



The locust, Cyrtacanthacris nigricornis, sometimes occurs in large 

 numbers in forests of teak and other wild trees and may spread to 

 plantations of Hevea. 



Injury to nursery plots and plantations by mites has often been 

 reported. Great damage is sometimes done to the young leaves, which 

 fall in such numbers as to cover the ground. In the plantations nothing 

 can be done, but on the seed-beds dusting with sulphur is effective. 



