348 
Philippine Journal of Science 
1919 
Certain species of wood are said to be naturally highly re- 
sistant to the termite. According to Thomas E. Snyder, forest 
entomologist of the United States Department of Agriculture, 
teak ( Tcctonci grandis) from Siam and Burma, greenheart 
( Nectandra rodiae) from South America and the West Indies, 
peroba (several species of Aspidosperma) from South America, 
and mahogany ( Sivietena mahogani ) from tropical America 
seem to be immune from the attack of the North American 
termites. 3 Hagen also states that teak ( Tectona grandis) and 
iron wood ( Sideroxylon ) of India are immune from attack by 
termites. 4 George P. Ahern, formerly director of the Philippine 
Bureau of Forestry, states that the following woods are not 
subject to attack by the anay, a native Philippine termite: 
Dinglas ( Eugenia bracteata Roxb. var. roxburghii Duthie), ipil 
( Intsia bijuga Gray), molave ( Vitex littoralis Dene.), and yacal 
( Hopea plagata Vidal). In addition to these, Cedrus deodar 
from India, Cedrus atlantica from northern Africa, Callitris 
glauca (cypress pine) from Queensland, Eucalyptus marginata 
from Australia, and Erythrophloeum lim from Cochin China are 
reported to be immune from termite attack. 
As a first step in the investigation it was necessary to prove 
whether these so-called immune timbers are really elfective in 
preventing termite attack or not. To do this, forty-five species 
of native and exotic woods were selected and the test carried on 
as follows: 
Method of investigation. — Each timber was cut into small 
blocks of definite size, 2 by 2 by 15 inches (about 5 by 5 by 38 
centimeters) ; hundreds of these blocks were buried in the 
infested ground; different kinds of timbers were mingled, care 
being taken not to group the same species in one place; from 
time to time all the blocks were dug out for inspection, and 
after eliminating the infested ones the others were buried again. 
Locality of the experiment stations. — Tainan, southern part of 
Formosa; and Matsubase, Kiushiu, Japan proper. 
Materials. — The woods that were used are enumerated in 
Table VIII. 
Result of the test at Tainan. — The ground was infested with 
Odontotermes formosanus (Shiraki), which is very common in 
the southern part of Formosa. The blocks were buried on 
November 17, 1912, and the final inspection was made on July 
15, 1913 . 
3 Bull. U. S. Bur. Ent. 94 s (1916) 79. 
4 Monogr. Term. 10: 44, 45. 
