and Magazine of the Geylon Agricultural Society. 



time termites are found to be doing real damage 

 to the roots, the application of " vaporite " will 

 soon drive them away. 



(3) Longicom Beetles. — A few instances have 

 come to my notice of the destruction of a 

 Hevea tree by the work of the grub of some 

 longicom beetle in the root. This grub is an 

 elongate worm-like creature of a whitish colour 

 with a reddish brown head, immediately behind 

 which the body is distinctly swollen. It tunnels 

 into the tap root and bores upwards into the 

 stump, causing the tree to snap off at or below 

 ground level. It is impossible to determine the 

 particular species ; but the adult insects would 

 probably bo largish beetles with very long 

 jointed antennae. Any beetles of this descrip- 

 tion that may be found frequenting the rubber 

 clearings should be treated as potential enemies. 

 It will be practically impossible to detect the 

 presence of the grub in the root before the 

 damage is done. 



II. — The Collar and Stem. 



Termites (White Ants). — Many stems riddled 

 by white ants have been received for report. In 

 every case it was evident that the termite attack 

 was of a secondary character. The parts had 

 been dead for a considerable time, and there 

 were abundant signs of fungus disease (of several 

 kinds) in the tissues. 



A single instance of a colony of Termcs inani? 

 inhabiting the hollow stem of a tree has come to 

 my notice. The insects were devouring the 

 wood inside, but left the bark above. The his- 

 tory of this tree was as follows: — The original 

 stem had been broken off by the wind and had 

 subsequently thrown up several strong suckers. 

 The termites were occupying a cavity in the old 

 stem at the base of the suckers. .At my recom- 

 mendation as much of the pest as possible was 

 scooped out, and the cavity was flooded with 

 naphthalin dissolved in petrel. This treatment 

 proved successful and the termites vacated 

 the tree. 



The " Gestroi Ant " ( Vermes gedroi) has fortu- 

 nately not been observed in Ueylon. It is said to 

 be a serious pest in the Federated Malay 

 States, and to be responsible for the death of 

 many well-grown trees. Mr E V Carey asserts 

 (Agricult. Bull, of Straits, No. 6, March, 190-2) 

 that they can be driven away by digging to a 

 depth of 2 or 3 feet for 10 feet round the affected 

 tree. Flooding the land (when practicable) has 

 also been suggested, but I have no records of the 

 results of such treatment. 



The common mound-building termites (Tcr- 

 ■ines rcdemanni and T. obsburideps) sometimes 

 construct galleries and screens of earth over the 

 stems of living rubber trees, but this need cause 

 no alarm if the tree is sound and healthy. They 

 merely eat off the functionless dead outer sur- 

 face of bark, leaving the stem smooth and clean. 

 As soon as thev have cleaned off the dry outer 

 bark, the insects will desert the tree of their own 

 accord. But if their presence on the stem is 

 considered undesirable, they may be prevented 

 by sprinkling the soil around the base of each 

 tree with a mixture of refuse petroleum and 

 water, as suggested by a writer in the "Indische 

 Mercuur" of July 30, 1907. About 1 part of the 

 oil to 20 of water are shaken up' together and 

 sprinkledonthe soil. This plan has been adopted 

 in Java, where it is said to be quite successful . 



(2) Bark-eating Tine.id Comceritis pieria, 

 Meyr.).— The caterpillars of this little moth 

 feed on the outer bark of living rubber trees, 

 but seldom penetrate far enough to cause any 

 flow of latex. They conceal themselves beneath 

 ascreen composed of fragments of bark and 

 their own excreta fastened together with silk 

 web. The insect can scarcely be called a pest, 

 as it does little or no appreciable damage. The 

 silken galleries can be easily brushed off by hand 



(3) Boring Uect'cs (Xylopzrtha mutilata. 

 VVlk.. — I have frequently received dead stems 

 of Hr-vea riddled by neat round holes of about 

 one-teenth of an inch in diameter. On splitting 

 the stem a small dark brown cylindrical beetle 

 isfound in each gallery. It is of a cylindrical 

 fo rm, rather more than a fourth of an inch in 

 length, and the hinder part of the body is 

 abruptly sloped off, as if it had been cut off 

 with a knife. The front is rounded and 

 roughened like a rasp. This beetle has been 

 observed only in dead or diseased wood, and 

 cannot be hold responsible for the original in- 

 jury. Appearances are deceptive in this as 

 in many other occurrences. The top of a tine 

 Hevea tree may be found to be dead and riddled 

 by these beetles ; and it is only natural that the 

 insects should be credited with the injury. But 

 one fact will show that the attack must have 

 been of a secondary nature. The entrance to the 

 burrow of Xylopcrtha will be found to be either 

 clear or (in still weather) marked by projecting 

 columns of powdered wood, which crumbles at a 

 touch. This could not have occurred if latex had 

 been present at the time of attack. In that case 

 the fragments would have been agglutinated to- 

 gether and would have formed irregular conglo- 

 merations outside the tunnels. The same and 

 allied species have attacked dry sections of rub- 

 ber stems exposed in the verandah of the 

 laboratory. 



Various small Scoli/tidcc (allied to but quite 

 distinct from the "Shot-hole Borer" of tea) are 

 often found in the dead stems, often in company 

 with the Xytapertha. In every case that has 

 come to my notice there is abundant evidence of 

 the previous existence of DipLodia or some other 

 parasitic fungus. In one instance it appoared at 

 lirst sightas though the beetles had really pene- 

 trated the living bark. There was an extensive exu- 

 dation of latex at the spot, and some of the beetle 

 holes were actually plugged with coagulated 

 latex. This led the superintendent of the estate 

 to believe that the latex was actually exuding 

 from the perforations made by the beetles ; 

 but a careful examination proved that the 

 latex had issued from cracks above the injured 

 part and had flowed over and into the perfora- 

 tions. Several of the insects were found en- 

 tangled in the clot of latex, killed in their 

 endeavour to force their way out through the 

 obstruction. In this case the sequence of events 

 was probably as follows :— A small area of bark 

 had been attacked by Diplodia ; boring beetles 

 had attacked the diseased spot ; the living bark 

 above the dead patch became fissured and 

 exuded latex, which flowed over the dead area, 

 imprisoning the insects. 



It is quite possible that small boring insects 

 may gain an entrance into the exposed wood 

 or depleted bark after a severe tapping, and that 



