388 



has been caused during the past few years. The insect feeds by sucking 

 the sap from the under-surface of the leaves, causing a whitish or 

 yellowish-brown discoloration, or the complete withering of the leaf 

 in severe cases. Where the host plant is shaded, feeding may also take 

 place on the upper surface of the leaf. Adults and nymphs were found 

 between 7th July and 1st September ; there may be two generations 

 annually and hibernation may take place in the adult stage. 



Green (E. E,). On some Animal Pests of the Hevea Rubber Tree. — 



Reprint frmn Trans. 3rd International Congress Trop. Agric, 

 London, 1916, pp. 608-636. [Received 14th July 1916.] 



Insect pests of hevea rubber [Hevea braziliensis] include : — • 

 Orthoptera : Autarches militaris (spotted locust) may appear in 

 injurious numbers in certain parts of Ceylon and cause the partial 

 defohation of young rubber trees. The habit of the adults of con- 

 gregating in large numbers for the purpose of egg-lapng renders their 

 capture easy. The ground beneath should then be broken up to a 

 depth of six inches and covered with quick-hme. Tropidacris cristata 

 is destructive to fohage in British Guiana, and Zonocerus elegans and 

 Z. variegafus attack the trees in a similar way in the Belgian Congo. 

 In the Straits Settlements Brachytrypes achatimis, Gymnogryllus 

 elegans and Cyrtacanthacris sp. bite through the stems and twigs of 

 seedhngs and carry the shoots into their burrows. In Java Cleandrus 

 sp. may split young stems for purposes of oviposition. 



Termites are not serious pests of rubber in Ceylon, the following 

 species having been occasionally met with : — Termes horni, T. obsairi- 

 ceps, T. redemanni and Eutermes inanis. Coptotermes (T.) gestroi is 

 important in Borneo, Java and Sumatra, where it attacks the heart- 

 wood of living trees, which are then liable to be broken off by 

 wind. C. marahitanos in Brazil is said to attack the areas of wood 

 exposed by tapping. 



Among the Hymenoptera, small bees and wasps frequently tunnel 

 in the ends of stumped plants, the cut ends of which have died back as 

 far as the node below. This condition can be remedied by stumping 

 the plant about half an inch above the node. 



Several Coleopterous pests are known. A Melolonthid, Lepidiota 

 pinguis, attacks the roots of hevea rubber, coffee and cinnamon in 

 Ceylon in the larval stage, injury being mainly confined to young 

 plants. The use of nitrate of soda or vaporite is recommended for 

 controlhng this species. A Rutelid, Cingala tenella, injures the 

 foliage of young plants to some extent. A species of Xylotrupes has a 

 similar habit in the Malay States, but with more serious results. The 

 Longicorn, Batocera ruhiis, has recently become a pest of hevea rubber 

 in Ceylon. Injury may take the form of a hollowing out of the tap 

 root or the destruction of the bark and wood at, or below the surface 

 of the soil. The normal method of entry of the larva is probably 

 through diseased areas in the bark. Methods of control include the 

 collection of adults, the removal of diseased parts and the tarring of 

 exposed surfaces. Maechotypa verrucicollis and Niphona sp. have been 

 recorded as feeding on the bark of young trees. Species of Curcu- 

 LiONiDAE which are occasionally injurious are, Astycus chrysochlorus 

 and Hypomeces squamosus in Malaya ; Dereodes curtus and Phytoscaphus 



