315 



twenty years ago, Japan occupied Formosa, which lies in a semi- 

 tropical region; that is, in the western Pacific Ocean, between the 

 southern and eastern China Seas. In this jjossession the people 

 have been compelled to tight against the common pest of the 

 Tropics, and the investigation of the biology of termites has be- 

 come one of the most important problems of the architect and the 

 entomologist. 



In Formosa and in Japan there are fourteen species of ter- 

 mites, four of which, namely Coptotermes formosanus, Leucoter- 

 mes spcratiis, Lcucotermes flaviceps, and Odontotermes formo- 

 sanus, are known as pests of wooden structures. Coptotermes 

 formosanus, which is distributed in Formosa, Riu Kiu Islands, 

 and in the southern parts of Japan proper, is especially formid- 

 able to buildings. It is certain that the other three attack wood- 

 work, and wooden structures as well, but their ravages are neg- 

 ligible in comparison with those of Coptotermes formosanus. 



During the last ten years. I have been investigating the Japanese 

 termites, especially the habits of Coptotermes formosanus. I ap- 

 proached the ])roblem of the method for prevention with the 

 jfollowing ideas as a working basis : 



1. Some changes are necessary with regard to the construction of build- 



ings in the Tropics in order to prevent damage by termites. 



2. The value of termite-proof building construction is not absolute, 

 unless all sorts of nonresistant timbers are eliminated from the 

 building materials. 



3. If it shall be proved that the elimination of nonresistant timbers 

 is practically impossible, it becomes necessary to treat them 

 chemically or physically in order to confer a special resistant 

 property. 



4. It is necessary to prove whether oi" not there are naturally resistant 



timbers in the Tropics. 



5. If there are naturally resistant timbers, an investigation with tlie 



object of discovering the cause of resistance becomes important. 



6. If the causes are definitely known^ methods of artificially treating 



nonresistant timbers vrill be more easily discovered. 



CERTAIN HABITS OF COPTOTERMES FORMOSANUS 



SHIRAKI 



DIFFERENT CASTES IN THE COLONY 



Generally the members of a termite colony dififer greatly at 

 different times of the year. Eggs and newly hatched larvse of 

 Coptotermes formosanus are most numerous in the summer; 

 winged forms and nymphs are not present after the swarming 

 season (from the end of May to the beginning of June) ; nymphs 

 increase in number in the spring, becoming most abundant in 

 April ; at the end of May the nymph changes to an imago and 

 usually swarms during the first ten days of June. A complete 

 colony contains the follou'ing castes : 



1. Newly hatched larvae. The heads of all are alike in dimensions 

 and provided with 10-jointed antennae. 



