2 R. Takahashi 



Among the parasitic Hymenoptera there ;ire about five very coiiinion 

 species in Formosa. 



Aphids present several unusual and remarkable peculiarities in 

 their life-history and in recent years considerable attention has been 

 paid to them in many parts of tlie world. A large amount of literature 

 has resulted from this studj', but the group still requires a thorough 

 investigation from several aspects. 



In the oriental region Prof, van der Goot and the late Mr. Das 

 made considerable progress in the systematic study of these insects. 

 The study of oriental Aphididae, however, is still quite in its infancj^ 

 less than one hundred and thirty species having been described from 

 Java, Ceylon, British India, Singapore and Hongkong and a con- 

 siderable number of species probably remain to be discovered and 

 worked up. 



From Formosa, Prof. Matsumura, Dr. Shiraki and Mr. Maki 

 have recorded about twenty-five species. 



At present there are about one hundred species known to occur in 

 the island, l)ut this number will be greatlj' increased as further studies 

 are made. 



These studies on the Formosan Apliididae were carried outcliiefly 

 at Taihoku under the direction of Dr. Shiraki, Chief of the Division 

 of Entomology, and the present publication forms only a part . 

 of the entire investigation. The results of further studies will be 

 published later. 



The types of the new species dealt with in this paper are 

 preserved in the collection of the entomological laboratory of lliis 

 station. All the drawings accompanying this paper were made 



by the author. 



The author here wishes to express his sincere thanks to Dr. 

 Shiraki for his kind and valuable help in conducting these investiga- 

 tions. 



The author's most cordial thanks are (hie to the Hon. Dr. K. 



