302 



The Supplement to the Tropical Agriculturist 



the depth of the water level, say two feet, and 

 should be examined the nest day when it will 

 often be found that the termites have made their 

 way across by means of a mud casing, thus 

 determining the direction of attack. 



It is a tedious matter at the best to follow up 

 these tunnels and it is on this account that I 

 have found it 



EXPEDIENT TO EXAMINE ALL TIMBER 



which 1 know to be likely to contain termitaria 

 before resorting to this means thereby saving 

 much time and expense. 



At first I gave rewards for the Queens and have 

 collected in thi3 way upwards of seventy un- 

 doubted specimens, but I find that by this method 

 the coolies waste much of their time in break- 

 ing up every smaller piece of the termitaria in 

 order to find the Queen cells. 



When a log or root containing the termitarium 

 has been discovered and destroyed and the 

 ground around it dug up it may safely be con- 

 cluded that the Queen has perished with the rest 

 of the individuals. Usually it is only necessary 

 to trace up the runs in the case of a nest occurring 

 in a buried stump or root, 



The first field I systematically cleared of all 

 timber five months ago has since shown no sign 

 of the pest. This field was planted with Ram- 

 bong about six years ago, it wus allowed to lapse 

 into°blnker and was interplanted with para in 

 L9U6. The only remaining timber was Kumpas 

 of which there was a considerable quantity. The 

 attack on both Para and Ram bong trees was 

 particularly virulent in this block but has now 

 entirely ceased. 



As Mr Pratt very truly says, owing to the cryp- 

 tic habits of termites it is very difficult to de- 

 termine when a tree is attacked until it falls 

 down; but during the wet season in October, 

 November, December and January the termites 

 frequently make their appearance above ground 

 and this fact I think should be taken advantage 

 of, by marking in some way all the trees on which 

 the termites make their appearance, for even if 

 they cannot be attended to at once, one would at 

 least know where to look for them in the future. 



I am afraid that some planters are lulled into 

 a sense of security by the fact that none of their 

 young trees have been attacked; it would be well 

 worth their while to make a search for T. ges- 

 hoi in the timber lying in clearings and if found, 

 take steps to eradicate the pest, for although 

 trees may not be attacked now, or perhaps for 

 a year or two to come, they will be attacked 

 sooner or later if T. gestroi is present 



I have not found a single tree attacked so far 

 in my forest clearings, but I know that T. ges- 

 troi is present. On the other hand in reclaimed 

 land, owing to the decay of most of the 

 timber, T. gestroi has wandered forth in search 

 of fresh fields and pastures new it has made 

 its presence evident by attacking young rubber 

 trees. 



On Fotore Clearings.— In these again the 

 importance of discovering the forest trees most 

 favoured by T. gestroi is evident. I cannot 

 speak from practical experience, but the obvious 

 course to p ursue would be tocut down all trees 

 known to harbour T. gestroi and allow them to 



dry for as long a period as possible, prior to 

 the felling of the land. Many of these 

 trees would be then destroyed in the burn 

 and those which remained could be burnt out by 

 piling over them the surrounding timber. This 

 would of course enhance the cost of clearing 

 perhaps by $10 or even $20 per acre, a small con- 

 sideration in comparison to the damage that 

 may be effected by T. gestroi. 



Further advantages of more thorough clearing 

 would be less likelihood of vacancies caused by 

 Forties semitostns and a saving in the cost of 

 weeding, in fact of every other work carried on 

 in the clearing together with easier and 



consequently more efficient supervision 



Drains as affecting Termes Gestroi.— I have 

 not in a single instance found the runs of ter- 

 mites crossing a sub-soil drain, excepting by 

 means of a fallen log or wooden bridge. It fol- 

 lows, therefore, that the more frequent the 

 drains, the more circumscribed will be the attack 

 of the termites, provided that iron or concrete 

 bridges are used instead of wooden ones and 

 that all timber lying across drains be removed. 



The mound termites, T. Malay anus, and T, 

 carbonarius seem to prefer the edge of a drain 

 for the construction of their termitaria but ges- 

 troi apparently considers the suitability of timber 

 only and not that of soil in choosing its home 



When nearing a drain the T. gestroi runs are 

 usuallyfound at a greater depth than elsewhere. 

 This is no doubt due to the facility with which 

 the termitoB are able to penetrate the soil which 



has become freer owing to good drainage 



Insecticides for, the Eradication of Termes 

 Gestroi. 



To anyone who has followed up a T. gestroi 

 tunnel, ramifying as it does sometimes for hun- 

 dreds of feet, or has seen the interior of a termi- 

 tarium with its myriads of individuals, the utter 

 futility of attempting to eradicate the pest by 

 means of insecticides must be apparent, but 

 insecticides will be found useful in killing the 

 comparatively few individuals which continue 

 their attack for some time after their terrai- 

 tarium is destroyed. I see that the custom of 

 applying lime to the tree attacked still continues 

 on some estates. This is utterly useless as a 

 preventative, or even as a means of keeping the 

 termites in check ; but it is useful as a means of 

 marking the trees attacked. 

 Crotalaria and Green Manures as Affecting 

 T. Gestroi. 



Crotalaria is undoubtedly of great advantage 

 as a green manure, but it has yet to be proved 

 if it is a means of cheapening the cost of weed- 

 ing. There are two objections to it which can 

 however be overcome. 



Firstly, 'the difficulty which is experienced in 

 eradicating gestroi and Fomes semitostns, will 

 be enormously increased by the fact that all 

 timber is hidden by growth rendering it neces- 

 sary to closely inspect each rubber tree and to 

 search about amongst the crotalaria for timber 

 containing T. gestroi. This can be overcome 

 by first eradicating the pest and then planting 

 green manure. Secondly when the green manure 

 is eventually killed out by shade, the rubber 

 tree will experience a shock from their custo 

 tnary supply of nitrogen bring^cut off. This can 



