APHIDIDAE OF FORMOSA— 3. 



By 



Ryoichi Takahashi 



Introduction 



The present paper is a continuation of the author's studies published as part 

 one (Agricultural Experiment Station, Formosa, Report Xo. 20, 1921) and part 

 two (Government Research Institute, Department of Agriculture, Formosa, Report 

 No. 4, 1923) under this general title. 



The study of the immature stages of Aphididae has been practically neglected, 

 and in the present report the author has presented the results of his studies on the 

 nymphs of these insects, and also will describe certain species from Formosa, as well 

 as others from Japan. Moreover, notes on certain species and keys for the identi- 

 fication of the nymphal instars are given. The species which are added in this 

 paper to the aphid-fauna of our island are as follows : 



3Iacrosiphum sniilacicola n. sp. 



M. perUlar n. sp. 



M. spp. 



Myms varians Davidson. 



M. plantagineus Pass? 



CajjitojjJiorus hragr/ii Gillette. 



a sp. 



Aphis petcmticola n. sp. 

 Aimrapliis artemisiae n. sp. 

 Ht/alopterus chenopodii Schrank. 

 Greenidea tenuicorpus Okajima. 

 MyzocalUs /ormosauus n. sp. 

 Dilaclmus formosamcs n. sp. 

 Unilachnus orientalis n. sp. 

 Aiceona osugii n. sp. 



Eriosoma dematicola n. sp. 



