480 



Termes umbrinus. 



This species nests in the stumps of dead trees and is often 

 seen on the march in enormous numbers frequently travelling a 

 distance of two or three hundred yards in columns a couple of 

 inches wide. It apparently feeds on dead leaves, twigs, etc., and 

 is occasionally seen in houses situated near jungle, but does not 

 do any harm. 



V. — Natural Habitat and Surroundings of 

 Termes Gestroi. 



Under normal conditions — i.e., on unopened land — Termes 

 gestroi, the only white ant with which we are concerned as an 

 agricultural pest, is by no means a common species in the 

 Federated Malay States. 



It has been met with, but only sporadically, in low-lying 

 jungle in the Kuala Selangor and Kuala Lumpur districts, and 

 is fairly common in the neighbourhood of Rantau Panjang and 

 behind Morib. 



So far as has been observed, it is scarce or does not occur on 

 granite and limestone soils, nor at any great elevation. Low 

 laterite hills, covered with small jungle, and older jungle growing 

 on land with a heavy clay sub-soil are the most favoured localities, 

 but as it has been met with outside the zone of cultivation only 

 on some twelve or fourteen occasions it is unwise to dogmatise 

 on the point. It is evident that wherever it exists some natural 

 cause must keep it rigidly in check, as otherwise the trees on 

 which it feeds would probably become extinct. 



VI. — Reasons for Present Abundance. 



Its present abundance is only an instance of what frequently 

 happens when the balance of nature is interfered with by the 

 operations of man, and one has only to mention as a case in 

 point, the plague of voles which occurred some years ago in the 

 South of Scotland and which was directly traced to high game 

 preserving and the consequent destruction of owls and hawks, 

 the natural enemies of the insectivore. 



The Phylloxera, too, originally an American insect, was never 

 seriously dangerous to American vines, whose roots possessed the 

 power of accommodation to the insect's attack. But when the 

 American vine stocks, and with them the Phylloxera, were intro- 

 duced into Europe, the native vines, which had not acquired this 

 resisting power, were rapidly attacked and destroyed. 



The conditions under which Para rubber is reputed to grow 

 in its native forests are not such as would favour the co-existence 

 of any great number of termites. The tree, therefore, when 

 transported to this country, has to contend with difficulties to 

 which the native Malayan trees have, under the stimulus of natu- 

 ral selection, become largely immune, and the increase of an 

 otherwise unimportant member of the local insect fauna is 

 abnormally stimulated. 



