338 Philippine Journal of Science 19 19 



mortar of brick walls vast numbers of soldiers are found. Such 

 being the case, it is said that the soldier of Coptotermes formo- 

 sanus attacks lime mortar by dissolving the lime with the 

 acidulous secretions. 



Damage to railway sleepers. — Coptotermes formosanus attacks 

 railway sleepers as well as buildings. According to a state- 

 ment of the Bureau of the Formosan Government Railway, the 

 life of an untreated, chestnut sleeper is only two years in For- 

 mosa, while in Japan proper it is from eight to ten years. 



In the southern part of Formosa another species of termite, 

 Odontotermes formosanus, also attacks the sleepers, as shown 

 in Plate VIII, fig. 3. The damage it causes is rather more 

 serious than that caused by Coptotermes formosanus. There- 

 fore, in the case of sleepers, it is important to prevent the 

 damage caused by these two species. Usually the length of the 

 spike which is used to fix the rail to a sleeper is a little greater 

 than the depth of the latter, so that its tip always penetrates 

 beyond the bottom of the sleeper, causing some damage to that 

 surface (Plate VIII, fig. 1). This point is most liable to be 

 attacked. As the pests excavate the wooden tissue surrounding 

 the spike (Plate VIII, fig. 2), the latter becomes ineffective. 

 Suppose such damage occurs successively in several sleepers; 

 the results are quite obvious — the rails spread and cause great 

 danger to passing trains. 



Damage to ships. — One can hardly believe that steamships 

 and launches in the water have been attacked by Coptotermes 

 formosanus; but it is an undeniable fact. There are many 

 records of such cases in the harbor of Keelung, Formosa. It 

 happens in this way. In the swarming season, many thousands 

 of winged males and females start from the nests in the vicinity 

 of the shore. Some of them have a chance to fly into the 

 ships moored in the harbor and there start new colonies. The 

 interior of the ship is dark enough to favor the establishment 

 of a nest. Usually the bottom of the ship is constructed of 

 Japanese pine, which is most durable in water; all the timbers 

 contain a favorable amount of water. Thus, all conditions being 

 exceedingly favorable to Coptotermes formosanus, the ravages 

 are extended step by step, until the vessel becomes unseaworthy, 

 because of the unexpected destruction of important parts of 

 the woodwork. In such a case extermination of the pests is 

 very difficult. When the Government trawler Ryokai-maru was 

 found to be infested, it was purposely sunk in the sea in order 

 to destroy the insects. 



