HoRi: Tow Nfw Species of Ai'iiids Parasitic on Poi-lak in Hokkaido III 



General measurements : 



Body length 2.760-3.375 mm. (av. 3. loSmni). Bodywidlh 1.013-1.229 mm. Antennae 1.688- 

 1.913mm. (av. 1.838 mm). Kore-wing 4.500 mm. Cornicles 0.281-0.319 mm. (av. 0.309); Max. width 

 0.096 mm. Min. width 0.051 mm. Fl.inge 0.074 mm. Cauda 0.210 mm; Width at the base 0.263 mm, 

 Thoracic horn 0.065 mm. Hind-tarsi 0.150 mm. 



(Apterous viviparous female) — Colouration and general appearance nuich 

 similar to those of the alate form. Antennae with no secondary senSoria, short, 

 a half length of the body; joint III the longest, slightly shorter than joints 

 IV and V ; IV etiiial to V ; unguis of VI much shorter than twice as long as 

 base. Rcstrum reaching between 2nd and 3rd coxae. Cauda broad and short, 

 a half length of the width at base. 



Meisurements of the antennal joints 



General measurements 



Body-length 3.243 mm. Body-width I.3i3mni, Antennae 1.388-1.781 mm. (av. 1.574 mm). Cor- 

 nicles 0.300-0.319 mm.; .Max. width 0.104 mm., Min. width 0.C64 mm., FLinge o.oSo mm. Cauda 0.150 

 mm.; Width at base 0.319 mm. Hind tarsi 0.150 mm. 



Food-plants — Popiihis spp. {Popiilus Maxiiiio-inc::ü, P. uionilifera, P. 

 nigra and P. alba). 



L o c a 1 i t y — Hokkaido (Sapporo and Kotoni). 



Observation s — This large aphid parasites on tne tender shoots and 

 the branches of the several species belonging to the genus Pofiiilus. During 

 early summer, numerous alatc forms migrate to the secondary host plant, which 

 we are unable to detect up to the present. Sexual forms, alate male and apter- 

 ous oviparous female, occur in November. Many eggs are laid on the buds 

 and rough barks. 



Remark s — This species somewhat resen.bles to MclanoxanthelUim bicolor 



