RUBBER 639 



timber on the land had rotted. T. gestroi as a pest of 

 the Para rubber tree is dying a natural death, and its rise 

 and fall is directly attributable to the exceptional facilities 

 offered when immense tracts of jungle were felled. 



Many hundreds of nests of T. gestroi, both in rubber 

 trees and in dead wood, have been examined care- 

 fully for queens, and there can be no doubt that the 

 queen is extremely rare. The majority of nests are 

 without queens, although both young and eggs may be 

 present. Haviland's opinion that the eggs are carried 

 from nest to nest seems the only feasible explanation of 

 their presence in so many nests without their being any 

 indication of a queen. The general construction of the 

 nest is always the same, but its extent varies consider- 

 ably. No mounds are ever made. As a rule the nest is 

 formed inside dead stumps, buried trees, or within fallen 

 trees on the surface of the ground. The main nests, of 

 which there may be ten or more in a single colony, are 

 formed of thin laminae of comminuted woody matter, and 

 are as fragile as the honeycombs formed by those species 

 which cultivate fungi. The nests are entire, but from 

 them proceed burrows which often connect with other 

 nests situated considerable distances away. On the coast 

 lands some of these runs have been traced for 600 ft. in 

 one direction, the separate nests of the colony being 

 anything from 25 to 200 ft. apart. These extensive 

 underground runs which link together the various nests 

 are flat and fairly broad, forming a passage into which 

 a microscope slide could be inserted. Within them 

 workers and soldiers are usually present, although a nest 

 may be 100 ft. away. Such extensive nests are met with 

 only on flat lands, but it is curious that even with such 

 large nests no queens were found. Should root diseases 

 be at all prevalent on an estate where there are large 

 connected underground colonies of T. gestroi, it is to be 

 expected that many trees will be attacked by this insect. 

 On the other hand, it is remarkable that this species is 

 the only termite found eating the living portions of a 

 rubber tree, although T. travians possesses many habits 

 in common with it, and is frequently found on rubber 

 estates. 



